# -*- coding: utf-8 -*-
"""
/***************************************************************************
 DsgTools
                                 A QGIS plugin
 Brazilian Army Cartographic Production Tools
                              -------------------
        begin                : 2018-10-04
        git sha              : $Format:%H$
        copyright            : (C) 2018 by João P. Esperidião - Cartographic Engineer @ Brazilian Army
        email                : esperidiao.joao@eb.mil.br
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
"""

from builtins import range
from itertools import combinations, chain
import math
from math import pi
from .geometryHandler import GeometryHandler
from .layerHandler import LayerHandler
from qgis.core import (
    QgsMessageLog,
    QgsVectorLayer,
    QgsGeometry,
    QgsField,
    QgsVectorDataProvider,
    QgsFeatureRequest,
    QgsExpression,
    QgsFeature,
    QgsSpatialIndex,
    Qgis,
    QgsCoordinateTransform,
    QgsWkbTypes,
    QgsProject,
    QgsVertexId,
    Qgis,
    QgsCoordinateReferenceSystem,
    QgsDataSourceUri,
    QgsFields,
    QgsProcessingMultiStepFeedback,
)
from qgis.PyQt.Qt import QObject
from qgis.PyQt.QtCore import QVariant


class NetworkHandler(QObject):
    (
        Flag,
        Sink,
        WaterwayBegin,
        UpHillNode,
        DownHillNode,
        Confluence,
        Ramification,
        AttributeChange,
        NodeNextToWaterBody,
        AttributeChangeFlag,
        NodeOverload,
        DisconnectedLine,
        DitchNode,
        SpillwayNode,
    ) = list(range(14))

    def __init__(self):
        super(NetworkHandler, self).__init__()
        self.geometryHandler = GeometryHandler()
        self.layerHandler = LayerHandler()
        self.nodeDict = None
        self.nodeTypeDict = None
        self.nodeTypeNameDict = {
            NetworkHandler.Flag: self.tr("Flag"),  # 0
            NetworkHandler.Sink: self.tr("Sink"),  # 1
            NetworkHandler.WaterwayBegin: self.tr("Waterway Beginning"),  # 2
            NetworkHandler.UpHillNode: self.tr("Up Hill Node"),  # 3
            NetworkHandler.DownHillNode: self.tr("Down Hill Node"),  # 4
            NetworkHandler.Confluence: self.tr("Confluence"),  # 5
            NetworkHandler.Ramification: self.tr("Ramification"),  # 6
            NetworkHandler.AttributeChange: self.tr("Attribute Change Node"),  # 7
            NetworkHandler.NodeNextToWaterBody: self.tr("Node Next to Water Body"),  # 8
            NetworkHandler.AttributeChangeFlag: self.tr("Attribute Change Flag"),  # 9
            NetworkHandler.NodeOverload: self.tr("Overloaded Node"),  # 10
            NetworkHandler.DisconnectedLine: self.tr("Disconnected From Network"),  # 11
            NetworkHandler.DitchNode: self.tr("Node next to ditch"),  # 12
            NetworkHandler.SpillwayNode: self.tr("Spillway"),
        }
        self.flagTextDict = {
            NetworkHandler.Flag: self.tr(
                "Segments must be connected and with correct flow."
            ),
            NetworkHandler.AttributeChangeFlag: self.tr(
                "Segments with same attribute set must be merged."
            ),
            NetworkHandler.DisconnectedLine: self.tr("Line disconnected From Network"),
            NetworkHandler.NodeOverload: self.tr("Node with flow problem"),
        }

    def identifyAllNodes(self, networkLayer, onlySelected=False, feedback=None):
        """
        Identifies all nodes from a given layer (or selected features of it).
        The result is returned as a dict of dict.
        :param networkLayer: target layer to which nodes identification is required.
        :return: {
            node_id : {
                start : [feature_which_starts_with_node],
                end : feature_which_ends_with_node
                }
            }
        """
        nodeDict = dict()
        isMulti = QgsWkbTypes.isMultiType(networkLayer.wkbType())
        iterator = (
            networkLayer.getFeatures()
            if not onlySelected
            else networkLayer.getSelectedFeatures()
        )
        featCount = (
            networkLayer.featureCount()
            if not onlySelected
            else networkLayer.selectedFeatureCount()
        )
        size = 100 / featCount if featCount else 0
        for current, feat in enumerate(iterator):
            if feedback is not None and feedback.isCanceled():
                break
            nodes = self.geometryHandler.getFeatureNodes(networkLayer, feat)
            if nodes != []:
                if isMulti:
                    if len(nodes) > 1:
                        # if feat is multipart and has more than one part, a flag should be raised
                        continue  # CHANGE TO RAISE FLAG
                    elif len(nodes) == 0:
                        # if no part is found, skip feature
                        continue
                    else:
                        # if feat is multipart, "nodes" is a list of list
                        nodes = nodes[0]
                # initial node
                pInit, pEnd = nodes[0], nodes[-1]
                # filling starting node information into dictionary
                if pInit not in nodeDict:
                    # if the point is not already started into dictionary, it creates a new item
                    nodeDict[pInit] = {"start": [], "end": []}
                if feat not in nodeDict[pInit]["start"]:
                    nodeDict[pInit]["start"].append(feat)
                # filling ending node information into dictionary
                if pEnd not in nodeDict:
                    nodeDict[pEnd] = {"start": [], "end": []}
                if feat not in nodeDict[pEnd]["end"]:
                    nodeDict[pEnd]["end"].append(feat)
            if feedback is not None:
                feedback.setProgress(size * current)
        return nodeDict

    def changeLineDict(self, nodeList, line):
        """
        Changes a line from a dict to another (start/end). Useful when network lines are flipped and another node
        identification is too costy.
        :param nodeList: (list-of-QgsPoint) the list of nodes connected to have given line relation dictionary changed.
        :param line: (QgsFeature) line to be flipped.
        :return: whether changing was successful for each node
        """
        for node in nodeList:
            # node's dicts
            startDict = self.nodeDict[node]["start"]
            endDict = self.nodeDict[node]["end"]
            if line in startDict:
                startDict.remove(line)
                endDict.append(line)
            elif line in endDict:
                startDict.append(line)
                endDict.remove(line)
            else:
                # if line is not found for some reason
                return False
        # if a nodeList is not found, method doesn't change anything
        return bool(nodeList)

    def nodeOnFrame(self, node, frameLyrContourList, searchRadius):
        """
        Identify whether or not node is over the frame. Returns True if point is over the frame and false if
        node is not on frame. If identification fails, returns 'None'.
        :param node: node (QgsPoint) to be identified as over the frame layer or not.
        :param frameLyrContourList: (list-of-QgsGeometry) border line for the frame layer to be checked.
        :param searchRadius: maximum distance to frame layer such that the feature is considered touching it.
        :return: (bool) whether node is as close as searchRaius to frame contour.
        """
        qgisPoint = QgsGeometry.fromPointXY(node)
        # building a buffer around node with search radius for intersection with Layer Frame
        buf = qgisPoint.buffer(searchRadius, -1)
        for frameContour in frameLyrContourList:
            if buf.intersects(frameContour):
                # it is condition enough one of the frame contours to be next to node
                return True
        return False

    def nodeNextToWaterBodies(
        self, node, waterBodiesLayers, searchRadius, auxIndexStructure=None
    ):
        """
        Identify whether or not node is next to a water body feature.
        :param node: (QgsPoint) node to be identified as next to a water body feature.
        :param waterBodiesLayers: (list-of-QgsVectorLayer) list of layers composing the water bodies on map.
        :param searchRadius: (float) maximum distance to frame layer such that the feature is considered touching it.
        :return: (bool) whether node is as close as searchRaius to a water body element.
        """
        qgisPoint = QgsGeometry.fromPointXY(node)
        # building a buffer around node with search radius for intersection with Layer Frame
        buf = qgisPoint.buffer(searchRadius, -1)
        # building bounding box around node for feature requesting
        bbRect = buf.boundingBox()
        # use aux spatial index if provided
        if auxIndexStructure is not None and "waterBodiesLayers" in auxIndexStructure:
            for auxDict in auxIndexStructure["waterBodiesLayers"]:
                for featid in auxDict["spatialIdx"].intersects(bbRect):
                    if buf.intersects(auxDict["idDict"][featid].geometry()):
                        # any feature component of a water body intersected is enough
                        return True
        else:
            for lyr in waterBodiesLayers:
                if lyr.geometryType() == 0:
                    # ignore point primitive layers
                    continue
                for feat in lyr.getFeatures(QgsFeatureRequest(bbRect)):
                    if buf.intersects(feat.geometry()):
                        # any feature component of a water body intersected is enough
                        return True
        return False

    def nodeIsWaterSink(
        self, node, waterSinkLayer, searchRadius, auxIndexStructure=None
    ):
        """
        Identify whether or not node is next to a water body feature. If no water sink layer is given, method returns False
        :param node: (QgsPoint) node to be identified as coincident with a water sink feature.
        :param waterSinkLayer: (QgsVectorLayer) layer containing the water sinks on map.
        :param searchRadius: (float) maximum distance to frame layer such that the feature is considered touching it.
        :return: (bool) whether node is as close as searchRaius to a water body element.
        """
        if not waterSinkLayer:
            return False
        qgisPoint = QgsGeometry.fromPointXY(node)
        # building bounding box around node for feature requesting
        bbRect = qgisPoint.buffer(searchRadius, -1).boundingBox()
        if auxIndexStructure is not None and "waterSinkLayer" in auxIndexStructure:
            for featid in auxIndexStructure["waterSinkLayer"]["spatialIdx"].intersects(
                bbRect
            ):
                if (
                    qgisPoint.distance(
                        auxIndexStructure["waterSinkLayer"]["idDict"][featid].geometry()
                    )
                    <= searchRadius
                ):
                    # any feature component of a water body intersected is enough
                    return True
        else:
            # check if qgisPoint (node geometry) is over a sink classified point
            for feat in waterSinkLayer.getFeatures(QgsFeatureRequest(bbRect)):
                if qgisPoint.distance(feat.geometry()) <= searchRadius:
                    # any feature component of a water body intersected is enough
                    return True
        return False

    def nodeIsSpillway(self, node, spillwayLayer, searchRadius, auxIndexStructure=None):
        """
        Identify whether or not node is next to a water body feature. If no water sink layer is given, method returns False
        :param node: (QgsPoint) node to be identified as coincident with a water sink feature.
        :param waterSinkLayer: (QgsVectorLayer) layer containing the water sinks on map.
        :param searchRadius: (float) maximum distance to frame layer such that the feature is considered touching it.
        :return: (bool) whether node is as close as searchRaius to a water body element.
        """
        if not spillwayLayer:
            return False
        qgisPoint = QgsGeometry.fromPointXY(node)
        # building bounding box around node for feature requesting
        bbRect = qgisPoint.buffer(searchRadius, -1).boundingBox()
        if auxIndexStructure is not None and "spillwayLayer" in auxIndexStructure:
            for featid in auxIndexStructure["spillwayLayer"]["spatialIdx"].intersects(
                bbRect
            ):
                if (
                    qgisPoint.distance(
                        auxIndexStructure["spillwayLayer"]["idDict"][featid].geometry()
                    )
                    <= searchRadius
                ):
                    # any feature component of a water body intersected is enough
                    return True
        else:
            # check if qgisPoint (node geometry) is over a sink classified point
            for feat in spillwayLayer.getFeatures(QgsFeatureRequest(bbRect)):
                if qgisPoint.distance(feat.geometry()) <= searchRadius:
                    # any feature component of a water body intersected is enough
                    return True
        return False

    def checkIfHasLineInsideWaterBody(self, node, waterBodiesLayers, searchRadius=None):
        """
        Checks whether one of ending lines connected to given node is inside of a water body feature.
        :param node: (QgsPoint) node to be identified having an ending line inside of a water body.
        :param waterBodiesLayers: (list-of-QgsVectorLayer) list of layers composing the water bodies on map.
        :return: (bool) whether node is as close as searchRaius to a water body element.
        """
        searchRadius = 1.0 if searchRadius is None else searchRadius
        qgisPoint = QgsGeometry.fromPointXY(node)
        # building a buffer around node with search radius for intersection with Layer Frame
        buf = qgisPoint.buffer(searchRadius, -1)
        # building bounding box around node for feature requesting
        bbRect = buf.boundingBox()
        # check if any wb feature inside of buffer area contains any ending line
        for line in self.nodeDict[node]["end"]:
            for lyr in waterBodiesLayers:
                for feat in lyr.getFeatures(QgsFeatureRequest(bbRect)):
                    if feat.geometry().contains(line.geometry()):
                        # any feature component of a water body intersected is enough
                        return True
        return False

    def getAttributesFromFeature(self, feature, layer, fieldList=None):
        """
        Retrieves the attributes from a given feature, except for
        their geometry and ID column values. If a list of
        attributes is given, method will return those attributes
        if found. In case no attribute is found, None will be returned.
        :param feature: (QgsFeature) feature from which attibutes will be retrieved.
        :param layer: (QgsVectorLayer) layer containing target feature.
        :param fieldList: (list-of-str) list of field names to be exposed.
        :return: (dict-of-object) attribute values for each attribute mapped.
        """
        # fields to be ignored
        fieldList = [] if fieldList is None else fieldList
        return {field: feature[field] for field in fieldList}

    def attributeChangeCheck(self, node, networkLayer, fieldList=None):
        """
        Checks if attribute change node is in fact an attribute change.
        :param node: (QgsPoint) node to be identified as over the frame layer or not.
        :param networkLayer: (QgsVectorLayer) layer containing network lines.
        :return: (bool) if lines connected to node do change attributes.
        """
        # assuming that attribute change nodes have only 1-in 1-out lines
        lineIn = self.nodeDict[node]["end"][0]
        atrLineIn = self.getAttributesFromFeature(
            feature=lineIn, layer=networkLayer, fieldList=fieldList
        )
        lineOut = self.nodeDict[node]["start"][0]
        atrLineOut = self.getAttributesFromFeature(
            feature=lineOut, layer=networkLayer, fieldList=fieldList
        )
        # comparing their dictionary of attributes, it is decided whether they share the exact same set of attributes (fields and values)
        return atrLineIn != atrLineOut

    def isFirstOrderDangle(
        self, node, networkLayer, searchRadius, auxIndexStructure=None
    ):
        """
        Checks whether node is a dangle into network (connected to a first order line).
        :param node: (QgsPoint) node to be validated.
        :param networkLayer: (QgsVectorLayer) network layer (line layer).
        :param searchRadius: (float) limit distance to another line.
        :return: (bool) indication whether node is a dangle.
        """
        qgisPoint = QgsGeometry.fromPointXY(node)
        # building a buffer around node with search radius for intersection with Layer Frame
        buf = qgisPoint.buffer(searchRadius, -1)
        # building bounding box around node for feature requesting
        bbRect = buf.boundingBox()
        if auxIndexStructure is not None and "networkLayer" in auxIndexStructure:
            # check if buffer intersects features from water bodies layers
            count = 0
            for featid in auxIndexStructure["networkLayer"]["spatialIdx"].intersects(
                bbRect
            ):
                if buf.intersects(
                    auxIndexStructure["networkLayer"]["idDict"][featid].geometry()
                ):
                    count += 1
                    res = count > 1
                    if res:
                        # to avoid as many iterations as possible
                        return False
        else:
            # check if buffer intersects features from water bodies layers
            count = 0
            for feat in networkLayer.getFeatures(QgsFeatureRequest(bbRect)):
                if buf.intersects(feat.geometry()):
                    count += 1
                    res = count > 1
                    if res:
                        # to avoid as many iterations as possible
                        return False
        return True

    def checkIfLineIsDisconnected(
        self, node, networkLayer, nodeTypeDict, geomType=None
    ):
        """
        Checks whether a waterway beginning node connected to a line disconnected from network.
        :param node: (QgsPoint) point to be classified.
        :param networkLayer: (QgsVectorLayer) network lines layer.
        :param nodeTypeDict: (dict) all current classified nodes and theirs types.
        :param geomType: (int) network layer geometry type code.
        :return: (bool) whether node is connected to a disconnected line
        """
        if not nodeTypeDict:
            # if there are no classified nodes, method is ineffective
            return False
        # if a line is disconnected from network, then the other end of the line would have to be classified as a waterway beginning as well
        if not geomType:
            geomType = networkLayer.geometryType()
        nextNodes = []
        # to reduce calculation time
        nodePointDict = self.nodeDict[node]
        isMulti = QgsWkbTypes.isMultiType(networkLayer.wkbType())
        # get all other nodes connected to lines connected to "node"
        lines = nodePointDict["start"] + nodePointDict["end"]
        if len(lines) > 1:
            # if there is at least one more line connected to node, line is not disconnected
            return False
        # get line nodes
        n = self.geometryHandler.getFeatureNodes(
            layer=networkLayer, feature=lines[0], geomType=geomType
        )
        if nodePointDict["start"]:
            # if line starts at target node, the other extremity is a final node
            if isMulti:
                if n is not None:
                    n = n[0][-1]
            elif n is not None:
                n = n[-1]
        elif nodePointDict["end"]:
            # if line starts at target node, the other extremity is a initial node
            if isMulti:
                if n is not None:
                    n = n[0][0]
            elif n:
                n = n[0]
        # if next node is not among the valid ending lines, it may still be connected to a disconnected line if it is a dangle
        # validEnds = [NetworkHandler.Sink, NetworkHandler.DownHillNode, NetworkHandler.NodeNextToWaterBody]
        if n in nodeTypeDict:
            # if both ends are classified as waterway beginning, then both ends are 1st order dangles and line is disconnected.
            return nodeTypeDict[n] in [
                NetworkHandler.WaterwayBegin,
                NetworkHandler.DownHillNode,
                NetworkHandler.UpHillNode,
                NetworkHandler.NodeNextToWaterBody,
            ]
            # if nodeTypeDict[n] not in validEnds:
            #     if self.isFirstOrderDangle(node=n, networkLayer=networkLayer, searchRadius=self.parameters[self.tr('Search Radius')]):
            #         # if next node is not a valid network ending node and is a dangle, line is disconnected from network
            #         return False
            #     return True
        # in case next node is not yet classified, method is ineffective
        return False

    def isNodeNextToDitch(self, node, ditchLayer, searchRadius, auxIndexStructure=None):
        """
        Checks if node is next to a ditch.
        ::param node: (QgsPoint) node to be identified as next to a water ditch feature.
        :param ditchLayer: layer composing the ditches on map.
        :param searchRadius: (float) maximum distance to frame layer such that the feature is considered touching it.
        :return: (bool) whether node is as close as searchRaius to a water body element.
        """
        if not ditchLayer:
            return False
        qgisPoint = QgsGeometry.fromPointXY(node)
        # building a buffer around node with search radius for intersection with Layer Frame
        buf = qgisPoint.buffer(searchRadius, -1)
        # building bounding box around node for feature requesting
        bbRect = buf.boundingBox()
        if auxIndexStructure is not None and "ditchLayer" in auxIndexStructure:
            for featid in auxIndexStructure["ditchLayer"]["spatialIdx"].intersects(
                bbRect
            ):
                if buf.intersects(
                    auxIndexStructure["ditchLayer"]["idDict"][featid].geometry()
                ):
                    # any feature component of a water body intersected is enough
                    return True
        else:
            # check if buffer intersects features from water bodies layers
            for feat in ditchLayer.getFeatures(QgsFeatureRequest(bbRect)):
                if buf.intersects(feat.geometry()):
                    # any feature component of a water body intersected is enough
                    return True
        return False

    def nodeType(
        self,
        nodePoint,
        networkLayer,
        frameLyrContourList,
        waterBodiesLayers,
        searchRadius,
        nodeTypeDict,
        waterSinkLayer=None,
        spillwayLayer=None,
        networkLayerGeomType=None,
        fieldList=None,
        ditchLayer=None,
        auxIndexStructure=None,
    ):
        """
        Get the node type given all lines that flows from/to it.
        :param nodePoint: (QgsPoint) point to be classified.
        :param networkLayer: (QgsVectorLayer) network lines layer.
        :param frameLyrContourList: (list-of-QgsGeometry) border line for the frame layer to be checked.
        :param waterBodiesLayers: (list-of-QgsVectorLayer) list of all waterbodies layer.
        :param searchRadius: (float) maximum distance to frame layer such that the feature is considered touching it.
        :param nodeTypeDict: (dict) dict with all currently classified nodes and their types.
        :param waterSinkLayer: (QgsVectorLayer) water sink layer.
        :param networkLayerGeomType: (int) network layer geometry type code.
        :return: returns the (int) point type.
        """
        fieldList = [] if fieldList is None else fieldList
        auxIndexStructure = {} if auxIndexStructure is None else auxIndexStructure
        # to reduce calculation time in expense of memory, which is cheap
        nodePointDict = self.nodeDict[nodePoint]
        sizeFlowOut = len(nodePointDict["start"])
        sizeFlowIn = len(nodePointDict["end"])
        hasStartLine = bool(sizeFlowOut)
        hasEndLine = bool(sizeFlowIn)
        if not networkLayerGeomType:
            networkLayerGeomType = networkLayer.geometryType()
        # "exclusive or"
        startXORendLine = hasStartLine != hasEndLine
        # # case 5: more than 3 lines flowing through one network line (it is forbidden as of Brazilian mapping norm EDGV)
        # if sizeFlowIn + sizeFlowOut > 3:
        #     return NetworkHandler.NodeOverload
        # case 1: all lines either flow in or out
        if startXORendLine:
            # case 1.a: point is over the frame
            if self.nodeOnFrame(
                node=nodePoint,
                frameLyrContourList=frameLyrContourList,
                searchRadius=searchRadius,
            ):
                # case 1.a.i: waterway is flowing away from mapped area (point over the frame has one line ending line)
                if hasEndLine:
                    return NetworkHandler.DownHillNode
                # case 1.a.ii: waterway is flowing to mapped area (point over the frame has one line starting line)
                elif hasStartLine:
                    return NetworkHandler.UpHillNode
            # case 1.b: point that legitimately only flows from
            elif hasEndLine:
                # case 1.b.i
                if self.nodeNextToWaterBodies(
                    node=nodePoint,
                    waterBodiesLayers=waterBodiesLayers,
                    searchRadius=searchRadius,
                    auxIndexStructure=auxIndexStructure,
                ):
                    # it is considered that every free node on map is a starting node. The only valid exceptions are nodes that are
                    # next to water bodies and water sink holes.
                    if sizeFlowIn == 1:
                        # a node next to water has to be a lose end
                        return NetworkHandler.NodeNextToWaterBody
                # force all lose ends to be waterway beginnings if they're not dangles (which are flags)
                elif self.isFirstOrderDangle(
                    node=nodePoint,
                    networkLayer=networkLayer,
                    searchRadius=searchRadius,
                    auxIndexStructure=auxIndexStructure,
                ):
                    if self.isNodeNextToDitch(
                        node=nodePoint,
                        ditchLayer=ditchLayer,
                        searchRadius=searchRadius,
                        auxIndexStructure=auxIndexStructure,
                    ):
                        # if point is not disconnected and is connected to a ditch
                        return NetworkHandler.DitchNode
                    # check if node is connected to a disconnected line
                    elif self.checkIfLineIsDisconnected(
                        node=nodePoint,
                        networkLayer=networkLayer,
                        nodeTypeDict=nodeTypeDict,
                        geomType=networkLayerGeomType,
                    ):
                        return NetworkHandler.DisconnectedLine
                    # case 1.b.ii: node is in fact a water sink and should be able to take an 'in' flow
                    elif self.nodeIsWaterSink(
                        node=nodePoint,
                        waterSinkLayer=waterSinkLayer,
                        searchRadius=searchRadius,
                        auxIndexStructure=auxIndexStructure,
                    ):
                        # if a node is indeed a water sink (operator has set it to a sink)
                        return NetworkHandler.Sink
                    elif self.nodeIsSpillway(
                        node=nodePoint,
                        spillwayLayer=spillwayLayer,
                        searchRadius=searchRadius,
                        auxIndexStructure=auxIndexStructure,
                    ):
                        # if node is a spillway
                        return NetworkHandler.SpillwayNode
                    return NetworkHandler.WaterwayBegin
            # case 1.c: point that legitimately only flows out
            elif hasStartLine and self.isFirstOrderDangle(
                node=nodePoint,
                networkLayer=networkLayer,
                searchRadius=searchRadius,
                auxIndexStructure=auxIndexStructure,
            ):
                if self.isNodeNextToDitch(
                    node=nodePoint,
                    ditchLayer=ditchLayer,
                    searchRadius=searchRadius,
                    auxIndexStructure=auxIndexStructure,
                ):
                    # if point is not disconnected and is connected to a ditch
                    return NetworkHandler.DitchNode
                elif self.checkIfLineIsDisconnected(
                    node=nodePoint,
                    networkLayer=networkLayer,
                    nodeTypeDict=nodeTypeDict,
                    geomType=networkLayerGeomType,
                ):
                    return NetworkHandler.DisconnectedLine
                elif self.nodeIsWaterSink(
                    node=nodePoint,
                    waterSinkLayer=waterSinkLayer,
                    searchRadius=searchRadius,
                    auxIndexStructure=auxIndexStructure,
                ):
                    # in case there's a wrongly acquired line connected to a water sink
                    return NetworkHandler.Sink
                elif self.nodeIsSpillway(
                    node=nodePoint,
                    spillwayLayer=spillwayLayer,
                    searchRadius=searchRadius,
                    auxIndexStructure=auxIndexStructure,
                ):
                    # if node is a spillway
                    return NetworkHandler.SpillwayNode
                return NetworkHandler.WaterwayBegin
            # case 1.d: points that are not supposed to have one way flow (flags)
            return NetworkHandler.Flag
        elif sizeFlowIn > sizeFlowOut:
            # case 2 "confluence"
            return NetworkHandler.Confluence
        elif sizeFlowIn == sizeFlowOut:
            if sizeFlowIn > 1:
                # case 4.a: there's a constant flow through node, but there are more than 1 line
                return NetworkHandler.NodeOverload
            elif self.attributeChangeCheck(
                node=nodePoint, networkLayer=networkLayer, fieldList=fieldList
            ):
                # case 4.b: lines do change their attribute set. Must use fieldList due to black list items.
                return NetworkHandler.AttributeChange
            elif self.isNodeNextToDitch(
                node=nodePoint,
                ditchLayer=ditchLayer,
                searchRadius=searchRadius,
                auxIndexStructure=auxIndexStructure,
            ):
                # case 4.c: lines next to ditches.
                return NetworkHandler.DitchNode
            else:
                # case 4.d: nodes inside the network that are there as an attribute change node but lines connected
                #           to it have the same set of attributes
                return NetworkHandler.AttributeChangeFlag
        else:
            # case 3 "ramification"
            return NetworkHandler.Ramification

    def classifyAllNodes(
        self,
        networkLayer,
        frameLyrContourList,
        waterBodiesLayers,
        searchRadius,
        waterSinkLayer=None,
        spillwayLayer=None,
        nodeList=None,
        feedback=None,
        attributeBlackList=None,
        ignoreVirtualFields=True,
        excludePrimaryKeys=True,
        ditchLayer=None,
    ):
        """
        Classifies all identified nodes from the hidrography line layer.
        :param networkLayer: (QgsVectorLayer) network lines layer.
        :param frameLyrContourList: (list-of-QgsFeature) border line for the frame layer.
        :param waterBodiesLayers: (list-of-QgsVectorLayer) list of all classes with water bodies to be compared to.
        :param searchRadius: (float) maximum distance to frame layer such that the feature is considered touching it.
        :param nodeList: a list of nodes (QgsPoint) to be classified. If not given, whole dict is going
                         to be classified. Node MUST be in dict given, if not, it'll be ignored.
        :param waterSinkLayer: (QgsVectorLayer) water sink layer.
        :param ditchLayer: (QgsVectorLayer) ditch layer.
        :return: a (dict) dictionary of node and its node type ( { (QgsPoint)node : (int)nodeType } ).
        """
        networkLayerGeomType = networkLayer.geometryType()
        nodeTypeDict = dict()
        flagNodeDict = dict()
        fieldList = self.layerHandler.getAttributesFromBlackList(
            networkLayer,
            attributeBlackList=attributeBlackList,
            ignoreVirtualFields=ignoreVirtualFields,
            excludePrimaryKeys=excludePrimaryKeys,
        )
        if feedback is not None:
            multiStepFeedback = QgsProcessingMultiStepFeedback(2, feedback)
            multiStepFeedback.setCurrentStep(0)
        auxIndexStructure = self.getAuxIndexStructure(
            networkLayer,
            waterBodiesLayers=waterBodiesLayers,
            spillwayLayer=spillwayLayer,
            waterSinkLayer=waterSinkLayer,
            ditchLayer=ditchLayer,
            feedback=multiStepFeedback,
        )
        nodeCount = len(self.nodeDict)
        size = 100 / nodeCount if nodeCount else 0
        if feedback is not None:
            multiStepFeedback.setCurrentStep(1)
        for current, node in enumerate(self.nodeDict):
            if multiStepFeedback is not None and multiStepFeedback.isCanceled():
                break
            if node not in self.nodeDict:
                # in case user decides to use a list of nodes to work on, given nodes that are not identified will be ignored
                continue
            nodeClassification = self.nodeType(
                nodePoint=node,
                networkLayer=networkLayer,
                frameLyrContourList=frameLyrContourList,
                waterBodiesLayers=waterBodiesLayers,
                spillwayLayer=spillwayLayer,
                searchRadius=searchRadius,
                waterSinkLayer=waterSinkLayer,
                nodeTypeDict=nodeTypeDict,
                networkLayerGeomType=networkLayerGeomType,
                fieldList=fieldList,
                ditchLayer=ditchLayer,
                auxIndexStructure=auxIndexStructure,
            )
            nodeTypeDict[node] = nodeClassification
            if nodeClassification in self.flagTextDict:
                flagNodeDict[node] = self.flagTextDict[nodeClassification]
            if multiStepFeedback is not None:
                multiStepFeedback.setProgress(size * current)
        return nodeTypeDict, flagNodeDict

    def getAuxIndexStructure(
        self,
        networkLayer,
        waterBodiesLayers=None,
        waterSinkLayer=None,
        spillwayLayer=None,
        ditchLayer=None,
        feedback=None,
    ):
        auxStructDict = dict()
        steps = 1
        if waterBodiesLayers is not None:
            steps += len(waterBodiesLayers)
        if waterSinkLayer is not None:
            steps += 1
        if ditchLayer is not None:
            steps += 1
        multiStepFeedback = QgsProcessingMultiStepFeedback(steps, feedback)
        currStep = 0
        multiStepFeedback.setCurrentStep(currStep)
        spatialIdx, idDict = self.layerHandler.buildSpatialIndexAndIdDict(
            networkLayer, feedback=multiStepFeedback
        )
        auxStructDict["networkLayer"] = {"spatialIdx": spatialIdx, "idDict": idDict}
        currStep += 1
        if waterBodiesLayers is not None:
            auxStructDict["waterBodies"] = []
            multiStepFeedback.setCurrentStep(currStep)
            for lyr in waterBodiesLayers:
                spatialIdx, idDict = self.layerHandler.buildSpatialIndexAndIdDict(
                    lyr, feedback=multiStepFeedback
                )
                auxStructDict["waterBodies"].append(
                    {"spatialIdx": spatialIdx, "idDict": idDict}
                )
            currStep += 1
        if waterSinkLayer is not None:
            multiStepFeedback.setCurrentStep(currStep)
            spatialIdx, idDict = self.layerHandler.buildSpatialIndexAndIdDict(
                waterSinkLayer, feedback=multiStepFeedback
            )
            auxStructDict["waterSinkLayer"] = {
                "spatialIdx": spatialIdx,
                "idDict": idDict,
            }
            currStep += 1
        if spillwayLayer is not None:
            multiStepFeedback.setCurrentStep(currStep)
            spatialIdx, idDict = self.layerHandler.buildSpatialIndexAndIdDict(
                spillwayLayer, feedback=multiStepFeedback
            )
            auxStructDict["spillwayLayer"] = {
                "spatialIdx": spatialIdx,
                "idDict": idDict,
            }
            currStep += 1
        if ditchLayer is not None:
            multiStepFeedback.setCurrentStep(currStep)
            spatialIdx, idDict = self.layerHandler.buildSpatialIndexAndIdDict(
                ditchLayer, feedback=multiStepFeedback
            )
            auxStructDict["ditchLayer"] = {"spatialIdx": spatialIdx, "idDict": idDict}
            currStep += 1
        return auxStructDict

    def clearHidNodeLayer(self, nodeLayer, nodeIdList=None, commitToLayer=False):
        """
        Clears all (or a given list of points) hidrography nodes on layer.
        :param nodeLayer: (QgsVectorLayer) hidrography nodes layer.
        :param nodeIdList: (list-of-int) list of node IDs to be cleared from layer.
        :param commitToLayer: (bool) indicates whether changes should be commited to layer.
        """
        nodeLayer.beginEditCommand("Clear Nodes")
        if not nodeIdList:
            nodeIdList = [feat.id() for feat in nodeLayer.getFeatures()]
        nodeLayer.deleteFeatures(nodeIdList)
        nodeLayer.endEditCommand()
        # commit changes to LAYER
        if commitToLayer:
            nodeLayer.commitChanges()

    def fillNodeLayer(self, nodeLayer, networkLineLayerName, commitToLayer=False):
        """
        Populate hidrography node layer with all nodes.
        :param nodeLayer: (QgsVectorLayer) hidrography nodes layer.
        :param networkLineLayerName: (str) network line layer name.
        :param commitToLayer: (bool) indicates whether changes should be commited to layer.
        """
        # if table is going to be filled, then it needs to be cleared first
        self.clearHidNodeLayer(nodeLayer=nodeLayer, commitToLayer=commitToLayer)
        # get fields from layer in order to create new feature with the same attribute map
        fields = nodeLayer.fields()
        nodeLayer.beginEditCommand("Create Nodes")
        # to avoid unnecessary calculation inside loop
        nodeTypeKeys = self.nodeTypeDict.keys()
        # initiate new features list
        featList = []
        for node in self.nodeDict:
            # set attribute map
            feat = QgsFeature(fields)
            # set geometry
            feat.setGeometry(QgsGeometry.fromMultiPointXY([node]))
            feat["node_type"] = (
                self.nodeTypeDict[node] if node in nodeTypeKeys else None
            )
            feat["layer"] = networkLineLayerName
            featList.append(feat)
        nodeLayer.addFeatures(featList)
        nodeLayer.endEditCommand()
        if commitToLayer:
            nodeLayer.commitChanges()

    def getFirstNode(self, lyr, feat, geomType=None):
        """
        Returns the starting node of a line.
        :param lyr: layer containing target feature.
        :param feat: feature which initial node is requested.
        :param geomType: (int) layer geometry type (1 for lines).
        :return: starting node point (QgsPoint).
        """
        n = self.geometryHandler.getFeatureNodes(
            layer=lyr, feature=feat, geomType=geomType
        )
        isMulti = QgsWkbTypes.isMultiType(lyr.wkbType())
        if isMulti:
            if len(n) > 1:
                return
            return n[0][0]
        elif n is not None:
            return n[0]

    def getSecondNode(self, lyr, feat, geomType=None):
        """
        Returns the second node of a line.
        :param lyr: layer containing target feature.
        :param feat: feature which initial node is requested.
        :param geomType: (int) layer geometry type (1 for lines).
        :return: starting node point (QgsPoint).
        """
        n = self.geometryHandler.getFeatureNodes(
            layer=lyr, feature=feat, geomType=geomType
        )
        isMulti = QgsWkbTypes.isMultiType(lyr.wkbType())
        if isMulti:
            if len(n) > 1:
                # process doesn't treat multipart features that does have more than 1 part
                return
            return n[0][1]
        elif n:
            return n[1]

    def getPenultNode(self, lyr, feat, geomType=None):
        """
        Returns the penult node of a line.
        :param lyr: layer containing target feature.
        :param feat: feature which last node is requested.
        :param geomType: (int) layer geometry type (1 for lines).
        :return: ending node point (QgsPoint).
        """
        n = self.geometryHandler.getFeatureNodes(
            layer=lyr, feature=feat, geomType=geomType
        )
        isMulti = QgsWkbTypes.isMultiType(lyr.wkbType())
        if isMulti:
            if len(n) > 1:
                return
            return n[0][-2]
        elif n:
            return n[-2]

    def getLastNode(self, lyr, feat, geomType=None):
        """
        Returns the ending point of a line.
        :param lyr: (QgsVectorLayer) layer containing target feature.
        :param feat: (QgsFeature) feature which last node is requested.
        :param geomType: (int) layer geometry type (1 for lines).
        :return: ending node point (QgsPoint).
        """
        n = self.geometryHandler.getFeatureNodes(
            layer=lyr, feature=feat, geomType=geomType
        )
        isMulti = QgsWkbTypes.isMultiType(lyr.wkbType())
        if isMulti:
            if len(n) > 1:
                return
            return n[0][-1]
        elif n is not None:
            return n[-1]

    def calculateAngleDifferences(self, startNode, endNode):
        """
        Calculates the angle in degrees formed between line direction ('startNode' -> 'endNode') and vertical passing over
        starting node.
        :param startNode: node (QgsPoint) reference for line and angle calculation.
        :param endNode: ending node (QgsPoint) for (segment of) line of which angle is required.
        :return: (float) angle in degrees formed between line direction ('startNode' -> 'endNode') and vertical passing over 'startNode'
        """
        # the returned angle is measured regarding 'y-axis', with + counter clockwise and -, clockwise.
        # Then angle is ALWAYS 180 - ang
        return 180 - math.degrees(
            math.atan2(endNode.x() - startNode.x(), endNode.y() - startNode.y())
        )

    def calculateAzimuthFromNode(self, node, networkLayer, geomType=None):
        """
        Computate all azimuths from (closest portion of) lines flowing in and out of a given node.
        :param node: (QgsPoint) hidrography node reference for line and angle calculation.
        :param networkLayer: (QgsVectorLayer) hidrography line layer.
        :param geomType: (int) layer geometry type (1 for lines).
        :return: dict of azimuths of all lines ( { featId : azimuth } )
        """
        if not geomType:
            geomType = networkLayer.geometryType()
        nodePointDict = self.nodeDict[node]
        azimuthDict = dict()
        for line in nodePointDict["start"]:
            # if line starts at node, then angle calculate is already azimuth
            endNode = self.getSecondNode(lyr=networkLayer, feat=line, geomType=geomType)
            azimuthDict[line] = node.azimuth(endNode)
        for line in nodePointDict["end"]:
            # if line ends at node, angle must be adapted in order to get azimuth
            endNode = self.getPenultNode(lyr=networkLayer, feat=line, geomType=geomType)
            azimuthDict[line] = node.azimuth(endNode)
        return azimuthDict

    def checkLineDirectionConcordance(
        self, line_a, line_b, networkLayer, geomType=None
    ):
        """
        Given two lines, this method checks whether lines flow to/from the same node or not.
        If they do not have a common node, method returns false.
        :param line_a: (QgsFeature) line to be compared flowing to a common node.
        :param line_b: (QgsFeature) the other line to be compared flowing to a common node.
        :param networkLayer: (QgsVectorLayer) hidrography line layer.
        :return: (bool) True if lines are flowing to/from the same.
        """
        if not geomType:
            geomType = networkLayer.geometryType()
        # first and last node of each line
        fn_a = self.getFirstNode(lyr=networkLayer, feat=line_a, geomType=geomType)
        ln_a = self.getLastNode(lyr=networkLayer, feat=line_a, geomType=geomType)
        fn_b = self.getFirstNode(lyr=networkLayer, feat=line_b, geomType=geomType)
        ln_b = self.getLastNode(lyr=networkLayer, feat=line_b, geomType=geomType)
        # if lines are flowing to/from the same node (they are flowing the same way)
        return fn_a == fn_b or ln_a == ln_b

    def validateDeltaLinesAngV2(
        self, node, networkLayer, connectedValidLines, geomType=None
    ):
        """
        Validates a set of lines connected to a node as for the angle formed between them.
        :param node: (QgsPoint) hidrography node to be validated.
        :param networkLayer: (QgsVectorLayer) hidrography line layer.
        :param connectedValidLines: list of (QgsFeature) lines connected to 'node' that are already verified.
        :param geomType: (int) layer geometry type. If not given, it'll be evaluated OTF.
        :return: (list-of-obj [dict, dict, str]) returns the dict. of valid lines, dict of inval. lines and
                 invalidation reason, if any, respectively.
        """
        val, inval, reason = dict(), dict(), ""
        if not geomType:
            geomType = networkLayer.geometryType()
        azimuthDict = self.calculateAzimuthFromNode(
            node=node, networkLayer=networkLayer, geomType=None
        )
        lines = azimuthDict.keys()
        for idx1, key1 in enumerate(lines):
            if idx1 == len(lines):
                # if first comparison element is already the last feature, all differences are already computed
                break
            for idx2, key2 in enumerate(lines):
                if idx1 >= idx2:
                    # in order to calculate only f1 - f2, f1 - f3, f2 - f3 (for 3 features, for instance)
                    continue
                absAzimuthDifference = math.fmod(
                    (azimuthDict[key1] - azimuthDict[key2] + 360), 360
                )
                if absAzimuthDifference > 180:
                    # the lesser angle should always be the one to be analyzed
                    absAzimuthDifference = 360 - absAzimuthDifference
                if absAzimuthDifference < 90:
                    # if it's a 'beak', lines cannot have opposing directions (e.g. cannot flow to/from the same node)
                    if not self.checkLineDirectionConcordance(
                        line_a=key1,
                        line_b=key2,
                        networkLayer=networkLayer,
                        geomType=geomType,
                    ):
                        reason = self.tr(
                            "Lines id={0} and id={1} have conflicting directions ({2:.2f} deg)."
                        ).format(key1.id(), key2.id(), absAzimuthDifference)
                        # checks if any of connected lines are already validated by any previous iteration
                        if key1 not in connectedValidLines:
                            inval[key1.id()] = key1
                        if key2 not in connectedValidLines:
                            inval[key2.id()] = key2
                        return val, inval, reason
                elif absAzimuthDifference != 90:
                    # if it's any other disposition, lines can have the same orientation
                    continue
                else:
                    # if lines touch each other at a right angle, then it is impossible to infer waterway direction
                    reason = self.tr(
                        "Cannot infer directions for lines {0} and {1} (Right Angle)"
                    ).format(key1.id(), key2.id())
                    if key1 not in connectedValidLines:
                        inval[key1.id()] = key1
                    if key2 not in connectedValidLines:
                        inval[key2.id()] = key2
                    return val, inval, reason
        if not inval:
            val = {k.id(): k for k in lines}
        return val, inval, reason

    def checkNodeTypeValidity(
        self, node, connectedValidLines, networkLayer, geomType=None
    ):
        """
        Checks if lines connected to a node have their flows compatible to node type and valid lines
        connected to it.
        :param node: (QgsPoint) node which lines connected to it are going to be verified.
        :param connectedValidLines: list of (QgsFeature) lines connected to 'node' that are already verified.
        :param networkLayer: (QgsVectorLayer) layer that contains the lines of analyzed network.
        :param geomType: (int) layer geometry type. If not given, it'll be evaluated OTF.
        :return: (list-of-obj [dict, dict, str]) returns the dict. of valid lines, dict of inval. lines and
                 invalidation reason, if any, respectively.
        """
        # getting flow permitions based on node type
        # reference is the node (e.g. 'in' = lines  are ENDING at analyzed node)
        flowType = {
            NetworkHandler.Flag: None,  # 0 - Flag (fim de trecho sem 'justificativa espacial')
            NetworkHandler.Sink: "in",  # 1 - Sumidouro
            NetworkHandler.WaterwayBegin: "out",  # 2 - Fonte D'Água
            NetworkHandler.DownHillNode: "in",  # 3 - Interrupção à Jusante
            NetworkHandler.UpHillNode: "out",  # 4 - Interrupção à Montante
            NetworkHandler.Confluence: "in and out",  # 5 - Confluência
            NetworkHandler.Ramification: "in and out",  # 6 - Ramificação
            NetworkHandler.AttributeChange: "in and out",  # 7 - Mudança de Atributo
            NetworkHandler.NodeNextToWaterBody: "in or out",  # 8 - Nó próximo a corpo d'água
            NetworkHandler.AttributeChangeFlag: None,  # 9 - Nó de mudança de atributos conectado em linhas que não mudam de atributos
            NetworkHandler.NodeOverload: None,  # 10 - Há igual número de linhas (>1 para cada fluxo) entrando e saindo do nó
            NetworkHandler.DisconnectedLine: None,  # 11 - Nó conectado a uma linha perdida na rede (teria dois inícios de rede)
            NetworkHandler.DitchNode: "in and out",  # 12 - Nó de vala
            NetworkHandler.SpillwayNode: "out",  # 13 - Vertedouro
        }
        # to avoid calculations in expense of memory
        nodeType = self.nodeTypeDict[node]
        # if node is introduced by operator's modification, it won't be saved to the layer
        if node not in self.nodeTypeDict.keys() and not self.unclassifiedNodes:
            self.unclassifiedNodes = True
            QMessageBox.warning(
                self.iface.mainWindow(),
                self.tr("Error!"),
                self.tr(
                    "There are unclassified nodes! Node (re)creation process is recommended before this process."
                ),
            )
            return None, None, None
        flow = flowType[int(nodeType)]
        nodePointDict = self.nodeDict[node]
        # getting all connected lines to node that are not already validated
        linesNotValidated = set(nodePointDict["start"] + nodePointDict["end"]) - set(
            connectedValidLines
        )
        # starting dicts of valid and invalid lines
        validLines, invalidLines = dict(), dict()
        if not flow:
            # flags have all lines flagged
            if nodeType == NetworkHandler.Flag:
                reason = self.tr(
                    "Node was flagged upon classification (probably cannot be an ending hidrography node)."
                )
                invalidLines = {line.id(): line for line in linesNotValidated}
            elif nodeType == NetworkHandler.AttributeChangeFlag:
                if nodePointDict["start"] and nodePointDict["end"]:
                    # in case manual error is inserted, this would raise an exception
                    line1, line2 = nodePointDict["start"][0], nodePointDict["end"][0]
                    id1, id2 = line1.id(), line2.id()
                    reason = self.tr(
                        "Redundant node. Connected lines ({0}, {1}) share the same set of attributes."
                    ).format(id1, id2)
                    if line1 in linesNotValidated:
                        il = line1
                    else:
                        il = line2
                    invalidLines[il.id()] = il
                else:
                    # problem is then, reclassified as a flag
                    self.nodeTypeDict[node] = NetworkHandler.Flag
                    # reclassify node type into layer
                    self.reclassifyNodeType[node] = NetworkHandler.Flag
                    reason = self.tr(
                        "Node was flagged upon classification (probably cannot be an ending hidrography node)."
                    )
            elif nodeType == NetworkHandler.DisconnectedLine:
                # get line connected to node
                lines = nodePointDict["start"] + nodePointDict["end"]
                # just in case there's a node wrong manual reclassification so code doesn't raise an error
                ids = [str(line.id()) for line in lines]
                invalidLines = {line.id(): line for line in lines}
                reason = self.tr("Line {0} disconnected from network.").format(
                    ", ".join(ids)
                )
            elif nodeType == NetworkHandler.NodeOverload:
                reason = self.tr(
                    "Node is overloaded - 4 or more lines are flowing in (>= 2 lines) and out (>= 2 lines)."
                )
                invalidLines = {line.id(): line for line in linesNotValidated}
            return validLines, invalidLines, reason
        if not linesNotValidated:
            # if there are no lines to be validated, method returns None
            return validLines, invalidLines, ""
        # if 'geomType' is not given, it must be evaluated
        if not geomType:
            geomType = networkLayer.geometryType()
        # reason message in case of invalidity
        reason = ""
        for line in linesNotValidated:
            # getting last and initial node from analyzed line
            finalNode = self.getLastNode(lyr=networkLayer, feat=line, geomType=geomType)
            initialNode = self.getFirstNode(
                lyr=networkLayer, feat=line, geomType=geomType
            )
            # line ID
            lineID = line.id()
            # comparing extreme nodes to find out if flow is compatible to node type
            if flow == "in":
                if node == finalNode:
                    if lineID not in validLines.keys():
                        validLines[lineID] = line
                elif lineID not in invalidLines.keys():
                    invalidLines[lineID] = line
                    reason = "".join(
                        [
                            reason,
                            self.tr(
                                "Line id={0} does not end at a node with IN flow type (node type is {1}). "
                            ).format(lineID, nodeType),
                        ]
                    )
            elif flow == "out":
                if node == initialNode:
                    if lineID not in validLines.keys():
                        validLines[lineID] = line
                elif lineID not in invalidLines.keys():
                    invalidLines[lineID] = line
                    reason = "".join(
                        [
                            reason,
                            self.tr(
                                "Line id={0} does not start at a node with OUT flow type (node type is {1}). "
                            ).format(lineID, self.nodeTypeNameDict[nodeType]),
                        ]
                    )
            elif flow == "in and out":
                if bool(len(nodePointDict["start"])) != bool(len(nodePointDict["end"])):
                    # if it's an 'in and out' flow and only one of dicts is filled, then there's an inconsistency
                    invalidLines[lineID] = line
                    thisReason = self.tr(
                        "Lines are either flowing only in or out of node. Node classification is {0}."
                    ).format(self.nodeTypeNameDict[nodeType])
                    if thisReason not in reason:
                        reason = "".join([reason, thisReason])
                elif node in [initialNode, finalNode]:
                    if lineID not in validLines:
                        validLines[lineID] = line
                elif lineID not in invalidLines:
                    invalidLines[lineID] = line
                    reason = "".join(
                        [
                            reason,
                            self.tr(
                                "Line {0} seems to be invalid (unable to point specific reason)."
                            ).format(lineID),
                        ]
                    )
            elif flow == "in or out":
                # these nodes can either be a waterway beginning or end
                # No invalidation reasons were thought at this point...
                if lineID not in validLines:
                    validLines[lineID] = line
        return validLines, invalidLines, reason

    def checkNodeValidity(
        self,
        node,
        connectedValidLines,
        networkLayer,
        geomType=None,
        deltaLinesCheckList=None,
    ):
        """
        Checks whether a node is valid or not.
        :param node: (QgsPoint) node which lines connected to it are going to be verified.
        :param connectedValidLines: list of (QgsFeature) lines connected to 'node' that are already verified.
        :param networkLayer: (QgsVectorLayer) layer that contains the lines of analyzed network.
        :param geomType: (int) layer geometry type. If not given, it'll be evaluated OTF.
        :param deltaLinesCheckList: (list-of-int) node types that must be checked for their connected lines angles.
        :return: (str) if node is invalid, returns the invalidation reason string.
        """

        if not deltaLinesCheckList:
            deltaLinesCheckList = [
                NetworkHandler.Confluence,
                NetworkHandler.Ramification,
            ]  # nodes that have an unbalaced number ratio of flow in/out
        # check coherence to node type and waterway flow
        val, inval, reason = self.checkNodeTypeValidity(
            node=node,
            connectedValidLines=connectedValidLines,
            networkLayer=networkLayer,
            geomType=geomType,
        )
        # checking angle validity
        if self.nodeTypeDict[node] in deltaLinesCheckList:
            # check for connected lines angles coherence
            val2, inval2, reason2 = self.validateDeltaLinesAngV2(
                node=node,
                networkLayer=networkLayer,
                connectedValidLines=connectedValidLines,
                geomType=geomType,
            )
            # if any invalid line was validated on because of node type, it shall be moved to invalid dict
            if reason2:
                # updates reason
                if reason:
                    reason = "; ".join([reason, reason2])
                else:
                    reason = reason2
                # remove any validated line in this iteration
                for lineId in inval2:
                    val.pop(lineId, None)
                # insert into invalidated dict
                inval.update(inval2)
        return val, inval, reason

    def getNextNodes(self, node, networkLayer, geomType=None):
        """
        It returns a list of all other nodes for each line connected to target node.
        :param node: (QgsPoint) node based on which next nodes will be gathered from.
        :param networkLayer: (QgsVectorLayer) hidrography line layer.
        :return: (list-of-QgsPoint) a list of the other node of lines connected to given hidrography node.
        """
        if not geomType:
            geomType = networkLayer.geometryType()
        nextNodes = []
        nodePointDict = self.nodeDict[node]
        for line in nodePointDict["start"]:
            # if line starts at target node, the other extremity is a final node
            nextNodes.append(
                self.getLastNode(lyr=networkLayer, feat=line, geomType=geomType)
            )
        for line in nodePointDict["end"]:
            # if line ends at target node, the other extremity is a initial node
            nextNodes.append(
                self.getFirstNode(lyr=networkLayer, feat=line, geomType=geomType)
            )
        return nextNodes

    def checkForStartConditions(
        self, node, validLines, networkLayer, nodeLayer, geomType=None
    ):
        """
        Checks if any of next nodes is a contour condition to directioning process.
        :param node: (QgsPoint) node which needs to have its next nodes checked.
        :param validLines: (list-of-QgsFeature) lines that were alredy checked and validated.
        :param networkLayer: (QgsVectorLayer) network lines layer.
        :param nodeLayer: (QgsVectorLayer) network nodes layer.
        :param geomType: (int) network lines layer geometry type code.
        :return:
        """
        # node type granted as right as start conditions
        inContourConditionTypes = [NetworkHandler.DownHillNode, NetworkHandler.Sink]
        outContourConditionTypes = [
            NetworkHandler.UpHillNode,
            NetworkHandler.WaterwayBegin,
            NetworkHandler.SpillwayNode,
        ]
        if node in inContourConditionTypes + outContourConditionTypes:
            # if node IS a starting condition, method is not necessary
            return False, ""
        nodes = self.getNextNodes(
            node=node, networkLayer=networkLayer, geomType=geomType
        )
        # for faster calculation
        nodeTypeDictAlias = self.nodeTypeDict
        nodeDictAlias = self.nodeDict
        # list of flipped features, if any
        flippedLines, flippedLinesIds = [], []
        # dict indicating whether lines may be flipped or not
        nonFlippableDict, flippableDict = dict(), dict()
        # at first, we assume there are no start conditions on next nodes
        hasStartCondition = False
        for nn in nodes:
            # initiate/clear line variable
            line = None
            if nn in nodeTypeDictAlias:
                nodeType = nodeTypeDictAlias[nn]
            else:
                nodeType = self.classifyNode([nn, nodeTypeDictAlias])
                nodeTypeDictAlias[nn] = nodeType
                self.reclassifyNodeType[nn] = nodeType
            if nodeType in inContourConditionTypes:
                # if next node is a confirmed IN-flowing lines, no lines should start on it
                line = (
                    nodeDictAlias[nn]["start"][0]
                    if nodeDictAlias[nn]["start"]
                    else None
                )
                hasStartCondition = True
            elif nodeType in outContourConditionTypes:
                # if next node is a confirmed OUT-flowing lines, no lines should end on it
                line = nodeDictAlias[nn]["end"][0] if nodeDictAlias[nn]["end"] else None
                hasStartCondition = True
            if line:
                # if line is given, then flipping it is necessary
                self.flipSingleLine(line=line, layer=networkLayer, geomType=geomType)
                # if a line is flipped it must be changed in self.nodeDict
                self.updateNodeDict(
                    node=node, line=line, networkLayer=networkLayer, geomType=geomType
                )
                flippedLines.append(line)
                flippedLinesIds.append(str(line.id()))
                # validLines.append(line)
        # for speed-up
        initialNode = lambda x: self.getFirstNode(
            lyr=networkLayer, feat=x, geomType=geomType
        )
        lastNode = lambda x: self.getLastNode(
            lyr=networkLayer, feat=x, geomType=geomType
        )
        if flippedLines:
            # map is a for-loop in C
            reclassifyNodeAlias = (
                lambda x: nodeLayer.changeAttributeValue(
                    self.nodeIdDict[x], 2, int(self.reclassifyNodeType[x])
                )
                if self.reclassifyNode(node=x, nodeLayer=nodeLayer)
                else False
            )
            map(
                reclassifyNodeAlias,
                chain(map(initialNode, flippedLines), map(lastNode, flippedLines)),
            )
        return hasStartCondition, flippedLinesIds

    def directNetwork(self, networkLayer, nodeLayer, nodeList=None):
        """
        For every node over the frame [or set as a line beginning], checks for network coherence regarding
        to previous node classification and its current direction. Method considers bordering points as
        correctly classified.
        :param networkLayer: (QgsVectorLayer) hidrography lines layer from which node are created from.
        :param nodeList: a list of target node points (QgsPoint). If not given, all nodeDict will be read.
        :return: (dict) flag dictionary ( { (QgsPoint) node : (str) reason } ), (dict) dictionaries ( { (int)feat_id : (QgsFeature)feat } ) of invalid and valid lines.
        """
        startingNodeTypes = [
            NetworkHandler.UpHillNode,
            NetworkHandler.WaterwayBegin,
            NetworkHandler.SpillwayNode,
        ]  # node types that are over the frame contour and line BEGINNINGS
        deltaLinesCheckList = [
            NetworkHandler.Confluence,
            NetworkHandler.Ramification,
        ]  # nodes that have an unbalaced number ratio of flow in/out
        if not nodeList:
            # 'nodeList' must start with all nodes that are on the frame (assumed to be well directed)
            nodeList = [
                node
                for node, nodeType in self.nodeTypeDict.items()
                if nodeType in startingNodeTypes
            ]
            # if no node to start the process is found, process ends here
            if not nodeList:
                return None, None, self.tr("No network starting point was found")
        # to avoid unnecessary calculations
        geomType = networkLayer.geometryType()
        # initiating the list of nodes already checked and the list of nodes to be checked next iteration
        visitedNodes, newNextNodes = [], []
        nodeFlags = dict()
        # starting dict of (in)valid lines to be returned by the end of method
        validLines, invalidLines = dict(), dict()
        # initiate relation of modified features
        flippedLinesIds, mergedLinesString = set([]), ""
        while nodeList:
            for node in nodeList:
                # first thing to be done: check if there are more than one non-validated line (hence, enough information for a decision)
                if node in self.nodeDict:
                    startLines = self.nodeDict[node]["start"]
                    endLines = self.nodeDict[node]["end"]
                    if node not in self.nodeTypeDict:
                        # in case node is not classified
                        self.nodeTypeDict[node] = self.classifyNode([node, nodeLayer])
                        self.reclassifyNodeType[node] = self.nodeTypeDict[node]
                else:
                    # ignore node for possible next iterations by adding it to visited nodes
                    visitedNodes.append(node)
                    continue
                nodeLines = startLines + endLines
                validLinesList = validLines.values()
                if len(set(nodeLines) - set(validLinesList)) > 1:
                    hasStartCondition, flippedLines = self.checkForStartConditions(
                        node=node,
                        validLines=validLinesList,
                        networkLayer=networkLayer,
                        nodeLayer=nodeLayer,
                        geomType=geomType,
                    )
                    if hasStartCondition:
                        flippedLinesIds |= set(flippedLines)
                    else:
                        # if it is not connected to a start condition, check if node has a valid line connected to it
                        if set(nodeLines) & set(validLinesList):
                            # if it does and, check if it is a valid node
                            val, inval, reason = self.checkNodeValidity(
                                node=node,
                                connectedValidLines=validLinesList,
                                networkLayer=networkLayer,
                                deltaLinesCheckList=deltaLinesCheckList,
                                geomType=geomType,
                            )
                            # if node has a valid line connected to it and it is valid, then non-validated lines are proven to be in conformity to
                            # start conditions, then they should be validated and node should be set as visited
                            if reason:
                                # if there are more than 1 line not validated yet and no start conditions around it,
                                # node will neither be checked nor marked as visited
                                continue
                # check coherence to node type and waterway flow
                val, inval, reason = self.checkNodeValidity(
                    node=node,
                    connectedValidLines=validLinesList,
                    networkLayer=networkLayer,
                    deltaLinesCheckList=deltaLinesCheckList,
                    geomType=geomType,
                )
                # nodes to be removed from next nodes
                removeNode = []
                # if a reason is given, then node is invalid (even if there are no invalid lines connected to it).
                if reason:
                    # try to fix node issues
                    # note that val, inval and reason MAY BE MODIFIED - and there is no problem...
                    flippedLinesIds_, mergedLinesString_ = self.fixNodeFlagsNew(
                        node=node,
                        valDict=val,
                        invalidDict=inval,
                        reason=reason,
                        connectedValidLines=validLinesList,
                        networkLayer=networkLayer,
                        nodeLayer=nodeLayer,
                        geomType=geomType,
                        deltaLinesCheckList=deltaLinesCheckList,
                    )
                    # keep track of all modifications made
                    if flippedLinesIds_:
                        # IDs not registered yet will be added to final list
                        addIds = set(flippedLinesIds_) - set(flippedLinesIds)
                        # IDs that are registered will be removed (flipping a flipped line returns to original state)
                        removeIds = set(flippedLinesIds_) - addIds
                        flippedLinesIds = (set(flippedLinesIds) - removeIds) | addIds
                    if mergedLinesString_:
                        if not mergedLinesString:
                            mergedLinesString = mergedLinesString_
                        else:
                            ", ".join([mergedLinesString, mergedLinesString_])
                    # if node is still invalid, add to nodeFlagList and add/update its reason
                    if reason:
                        nodeFlags[node] = reason
                    # get next nodes connected to invalid lines
                    for line in inval.values():
                        if line in endLines:
                            removeNode.append(
                                self.getFirstNode(lyr=networkLayer, feat=line)
                            )
                        else:
                            removeNode.append(
                                self.getLastNode(lyr=networkLayer, feat=line)
                            )
                # set node as visited
                if node not in visitedNodes:
                    visitedNodes.append(node)
                # update general dictionaries with final values
                validLines.update(val)
                invalidLines.update(inval)
                # get next iteration nodes
                newNextNodes += self.getNextNodes(
                    node=node, networkLayer=networkLayer, geomType=geomType
                )
                # remove next nodes connected to invalid lines
                if removeNode:
                    newNextNodes = list(set(newNextNodes) - set(removeNode))
            # remove nodes that were already visited
            newNextNodes = list(set(newNextNodes) - set(visitedNodes))
            # if new nodes are detected, repeat for those
            nodeList = newNextNodes
            newNextNodes = []
        # log all features that were merged and/or flipped
        self.logAlteredFeatures(
            flippedLines=flippedLinesIds, mergedLinesString=mergedLinesString
        )
        return nodeFlags, invalidLines, validLines

    # method for automatic fix
    def getReasonType(self, reason):
        """
        Gets the type of reason. 0 indicates non-fixable reason.
        :param reason: (str) reason of node invalidation.
        :return: (int) reason type.
        """
        fixableReasonExcertsDict = {
            self.tr("does not end at a node with IN flow type"): 1,
            self.tr("does not start at a node with OUT flow type"): 2,
            self.tr("have conflicting directions"): 3,
            self.tr("Redundant node."): 4,
            self.tr("Node was flagged upon classification"): 5,
        }
        for r in fixableReasonExcertsDict:
            if r in reason:
                return fixableReasonExcertsDict[r]
        # if reason is not one of the fixables
        return 0

    # method for automatic fix
    def getLineIdFromReason(self, reason, reasonType):
        """
        Extracts line ID from given reason.
        :param reason: (str) reason of node invalidation.
        :param reasonType: (int) invalidation reason type.
        :return: (list-of-str) line ID (int as str).
        """
        if reasonType in [1, 2]:
            # Lines before being built:
            # self.tr('Line id={0} does not end at a node with IN flow type (node type is {1}). ')
            # self.tr('Line id={0} does not start at a node with OUT flow type (node type is {1}). ')
            return [reason.split(self.tr("id="))[1].split(" ")[0]]
        elif reasonType == 3:
            # Line before being built: self.tr('Lines id={0} and id={1} have conflicting directions ({2:.2f} deg).')
            lineId1 = reason.split(self.tr("id="))[1].split(" ")[0]
            lineId2 = reason.split(self.tr("id="))[2].split(" ")[0]
            return [lineId1, lineId2]
        elif reasonType == 4:
            # Line before being built: self.tr('Redundant node. Connected lines ({0}, {1}) share the same set of attributes.')
            lineId1 = reason.split(self.tr(", "))[0].split("(")[1]
            lineId2 = reason.split(self.tr(", "))[1].split(")")[0]
            return [lineId1, lineId2]
        else:
            # all other reasons can't have their ID extracted
            return []

    def flipSingleLine(self, line, layer, geomType=None):
        """
        Flips a given single line.
        :param line: (QgsFeature) line to be flipped.
        :param layer: (QgsVectorLayer) layer containing target feature.
        :param geomType: (int) layer geometry type code.
        """
        self.geometryHandler.flipFeature(layer=layer, feature=line, geomType=geomType)

    def flipInvalidLine(self, node, networkLayer, validLines, geomType=None):
        """
        Fixes lines connected to nodes flagged as one way flowing node where it cannot be.
        :param node: (QgsPoint) invalid node to have its lines flipped.
        :param networkLayer: (QgsVectorLayer) layer containing target feature.
        :param validLines: (list-of-QgsFeature) list of all validated lines.
        :param geomType: (int) layer geometry type code.
        :return: (QgsFeature) flipped line.
        """
        # get dictionaries for speed-up
        endDict = self.nodeDict[node]["end"]
        startDict = self.nodeDict[node]["start"]
        amountLines = len(endDict + startDict)
        # it is considered that
        if endDict:
            # get invalid line connected to node
            invalidLine = list(set(endDict) - set(validLines))
            if invalidLine:
                invalidLine = invalidLine[0]
        else:
            # get invalid line connected to node
            invalidLine = list(set(startDict) - set(validLines))
            if invalidLine:
                invalidLine = invalidLine[0]
        # if no invalid lines are identified, something else is wrong and flipping won't be the solution
        if not invalidLine:
            return None
        # flipping invalid line
        self.flipSingleLine(line=invalidLine, layer=networkLayer)
        return invalidLine

    def fixAttributeChangeFlag(self, node, networkLayer):
        """
        Merges the given 2 lines marked as sharing the same set of attributes.
        :param node: (QgsPoint) flagged node.
        :param networkLayer: (QgsVectorLayer) network lines layer.
        :return: (str) string containing which line was line the other.
        """
        line_a = self.nodeDict[node]["end"][0]
        line_b = self.nodeDict[node]["start"][0]
        # lines have their order changed so that the deleted line is the intial one
        self.mergeNetworkLines(line_a=line_b, line_b=line_a, layer=networkLayer)
        # the updated feature should be updated into node dict for the NEXT NODE!
        nn = self.getLastNode(lyr=networkLayer, feat=line_b, geomType=1)
        if nn in self.nodeDict:  # TODO: @jpesperidiao verifica isso por favor
            for line in self.nodeDict[nn]["end"]:
                if line.id() == line_b.id():
                    self.nodeDict[nn]["end"].remove(line)
                    self.nodeDict[nn]["end"].append(line_b)
        # remove attribute change flag node (there are no lines connected to it anymore)
        self.nodesToPop.append(node)
        return self.tr("{0} to {1}").format(line_a.id(), line_b.id())

    def updateNodeDict(self, node, line, networkLayer, geomType=None):
        """
        Updates node dictionary. Useful when direction of a (set of) line is changed.
        """
        # getting first and last nodes
        first = self.getFirstNode(lyr=networkLayer, feat=line, geomType=geomType)
        last = self.getLastNode(lyr=networkLayer, feat=line, geomType=geomType)
        changed = self.changeLineDict(nodeList=[first, last], line=line)
        return changed

    def reclassifyNode(self, node, nodeLayer):
        """
        Reclassifies node.
        :param node: (QgsPoint) node to be reclassified.
        :return: (bool) whether point was modified.
        """
        immutableTypes = [
            NetworkHandler.UpHillNode,
            NetworkHandler.DownHillNode,
            NetworkHandler.WaterwayBegin,
            NetworkHandler.SpillwayNode,
        ]
        if self.nodeTypeDict[node] in immutableTypes:
            # if node type is immutable, reclassification is not possible
            return False
        # get new type
        newType = self.classifyNode([node, self.nodeTypeDict])
        if self.nodeTypeDict[node] == newType:
            # if new node type is the same as new, method won't do anything
            return False
        # alter it in feature
        self.nodeTypeDict[node] = newType
        id_ = self.nodeIdDict[node]
        self.reclassifyNodeType[node] = newType
        return True

    def fixDeltaFlag(
        self, node, networkLayer, validLines, reason, reasonType=3, geomType=None
    ):
        """
        Tries to fix nodes flagged because of their delta angles.
        :param node: (QgsPoint) invalid node.
        :param network: (QgsVectorLayer) contains network lines.
        :param validLines: (list-of-QgsFeature) lines already validated.
        :param reason: (str) reason of node invalidation.
        :param reasonType: (int) code for invalidation reason.
        :param geomType: (int) code for the layer that contains the network lines.
        :return: (QgsFeature) line to be flipped. If no line is identified as flippable, None is returned.
        """
        flipCandidates = self.getLineIdFromReason(reason=reason, reasonType=reasonType)
        for line in self.nodeDict[node]["start"] + self.nodeDict[node]["end"]:
            lineId = str(line.id())
            if lineId in flipCandidates and line not in validLines:
                # flip line that is exposed in invalidation reason and is not previously validated
                self.flipSingleLine(line=line, layer=networkLayer, geomType=geomType)
                return line
        # if no line attend necessary requirements for flipping
        return None

    def fixNodeFlagsNew(
        self,
        node,
        valDict,
        invalidDict,
        reason,
        connectedValidLines,
        networkLayer,
        nodeLayer,
        geomType=None,
        deltaLinesCheckList=None,
    ):
        """
        Tries to fix issues flagged on node
        """
        # initiate lists of lines that were flipped/merged
        flippedLinesIds, mergedLinesString = [], []
        # support list of flipped lines
        flippedLines = []
        # get reason type
        reasonType = self.getReasonType(reason=reason)
        if not reasonType:
            # if node invalidation reason is not among the fixable ones, method stops here.
            return flippedLinesIds, mergedLinesString
        ## try to fix node issues
        if reasonType in [1, 2]:
            # original message: self.tr('Line {0} does not end at a node with IN flow type (node type is {1}). ')
            # original message: self.tr('Line {0} does not start at a node with OUT flow type (node type is {1}). ')
            # get flipping candidates
            featIdFlipCandidates = self.getLineIdFromReason(
                reason=reason, reasonType=reasonType
            )
            for lineId in featIdFlipCandidates:
                line = invalidDict[int(lineId)]
                if line not in connectedValidLines:
                    # only non-valid lines may be modified
                    self.flipSingleLine(
                        line=line, layer=networkLayer, geomType=geomType
                    )
                    flippedLinesIds.append(lineId)
                    flippedLines.append(line)
        elif reasonType == 3:
            # original message: self.tr('Lines {0} and {1} have conflicting directions ({2:.2f} deg).')
            line = self.fixDeltaFlag(
                node=node,
                networkLayer=networkLayer,
                reason=reason,
                validLines=connectedValidLines,
                reasonType=reasonType,
            )
            if line:
                # if a line is flipped it must be changed in self.nodeDict
                self.updateNodeDict(
                    node=node, line=line, networkLayer=networkLayer, geomType=geomType
                )
        elif reasonType == 4:
            # original message: self.tr('Redundant node. Connected lines ({0}, {1}) share the same set of attributes.')
            mergedLinesString = self.fixAttributeChangeFlag(
                node=node, networkLayer=networkLayer
            )
        elif reasonType == 5:
            # original message: self.tr('Node was flagged upon classification (probably cannot be an ending hidrography node).')
            line = self.flipInvalidLine(
                node=node,
                networkLayer=networkLayer,
                validLines=connectedValidLines,
                geomType=geomType,
            )
            if line:
                flippedLinesIds.append(str(line.id()))
                flippedLines.append(line)
                # if a line is flipped it must be changed in self.nodeDict
                self.updateNodeDict(
                    node=node, line=line, networkLayer=networkLayer, geomType=geomType
                )
        else:
            # in case, for some reason, a strange value is given to reasonType
            return [], ""
        # for speed-up
        initialNode = lambda x: self.getFirstNode(
            lyr=networkLayer, feat=x, geomType=geomType
        )
        lastNode = lambda x: self.getLastNode(
            lyr=networkLayer, feat=x, geomType=geomType
        )
        # reclassification re-evalution is only needed if lines were flipped
        if flippedLinesIds:
            # re-classify nodes connected to flipped lines before re-checking
            # map is a for-loop in C
            reclassifyNodeAlias = (
                lambda x: nodeLayer.changeAttributeValue(
                    self.nodeIdDict[x], 2, int(self.reclassifyNodeType[x])
                )
                if self.reclassifyNode(node=x, nodeLayer=nodeLayer)
                else None
            )
            map(
                reclassifyNodeAlias,
                chain(map(initialNode, flippedLines), map(lastNode, flippedLines)),
            )
            # check if node is fixed and update its dictionaries and invalidation reason
            valDict, invalidDict, reason = self.checkNodeValidity(
                node=node,
                connectedValidLines=connectedValidLines,
                networkLayer=networkLayer,
                geomType=geomType,
                deltaLinesCheckList=deltaLinesCheckList,
            )
        return flippedLinesIds, mergedLinesString

    def logAlteredFeatures(self, flippedLines, mergedLinesString, feedback=None):
        """
        Logs the list of flipped/merged lines, if any.
        :param flippedLines: (list-of-int) list of flipped lines.
        :param mergedLinesString: (str) text containing all merged lines (in the form of 'ID1 to ID2, ID3, to ID4')
        :return: (bool) whether or not a message was shown.
        """
        # building warning message
        warning = ""
        if flippedLines:
            warning = "".join(
                [
                    warning,
                    self.tr(
                        "Lines that were flipped while directioning hidrography lines: {0}\n\n"
                    ).format(", ".join(flippedLines)),
                ]
            )
        elif mergedLinesString:
            warning = "".join(
                [
                    warning,
                    self.tr(
                        "Lines that were merged while directioning hidrography lines: {0}\n\n"
                    ).format(mergedLinesString),
                ]
            )
        if warning:
            # warning is only raised when there were flags fixed
            if feedback is not None:
                warning = "".join(
                    [
                        self.tr(
                            "\nVerify Network Directioning: Flipped/Merged Lines\n"
                        ),
                        warning,
                    ]
                )
                feedback.pushInfo(warning)
            return True
        return False

    def getNodeTypeDictFromNodeLayer(self, networkNodeLayer, feedback=None):
        """
        Get all node info (dictionaries for start/end(ing) lines and node type) from node layer.
        :param networkNodeLayer: (QgsVectorLayer) network node layer.
        :return: (tuple-of-dict) node type dict and node id dict, respectively
        """
        nodeTypeDict, nodeIdDict = dict(), dict()
        isMulti = QgsWkbTypes.isMultiType(networkNodeLayer.wkbType())
        featCount = networkNodeLayer.featureCount()
        size = 100 / featCount if featCount else 0
        for current, feat in enumerate(networkNodeLayer.getFeatures()):
            if feedback is not None and feedback.isCanceled():
                break
            if isMulti:
                node = feat.geometry().asMultiPoint()[0]
            else:
                node = feat.geometry().asPoint()
            nodeTypeDict[node] = int(feat["node_type"])
            nodeIdDict[node] = feat.id()
            if feedback is not None:
                feedback.setProgress(size * current)
        return nodeTypeDict, nodeIdDict

    def clearAuxiliaryLinesLayer(
        self, invalidLinesLayer, lineIdList=None, commitToLayer=False
    ):
        """
        Clears all (or a given list of points) invalid lines from auxiliary lines layer.
        :param invalidLinesLayer: (QgsVectorLayer) invalid lines layer.
        :param lineIdList: (list-of-int) list of lines IDs to be cleared from layer.
        :param commitToLayer: (bool) indicates whether changes should be commited to layer.
        """
        # invalid reason texts
        invalidReason = self.tr("Connected to invalid hidrography node.")
        nonVisitedReason = self.tr("Line not yet visited.")
        invalidLinesLayer.beginEditCommand("Clear Invalid Lines")
        if lineIdList is None:
            # define a function to get only feature ids for invalid lines registered in invalidLinesLayer and use it in map, for speed-up
            getInvalidLineFunc = (
                lambda feat: feat.id()
                if feat["reason"] in [invalidReason, nonVisitedReason]
                else -9999
            )
            # list/set combination to remove possible duplicates of -9999 and avoid unnecessary calculation
            lineIdList = list(
                set(map(getInvalidLineFunc, invalidLinesLayer.getFeatures()))
            )
            if -9999 in lineIdList:
                lineIdList.remove(-9999)
        invalidLinesLayer.deleteFeatures(lineIdList)
        invalidLinesLayer.endEditCommand()
        # commit changes to LAYER
        if commitToLayer:
            invalidLinesLayer.commitChanges()

    def getAuxiliaryLines(
        self, fields, invalidLinesDict, nonValidatedLines, networkLayerName
    ):
        """
        Populate from auxiliary lines layer with all invalid lines.
        :param invalidLinesDict: (dict) dictionary containing all invalid lines to be displayed.
        :param nonValidatedLines: (set) set of all non-validated network lines.
        :param commitToLayer: (bool) indicates whether changes should be commited to layer.
        """
        # prepare generic variables that will be reused
        invalidReason = self.tr("Connected to invalid hidrography node.")
        nonVisitedReason = self.tr("Line not yet visited.")
        # initiate new features list
        featList = []
        # pre-declaring method to make it faster
        newInvalidFeatFunc = lambda x: self.createNewInvalidLineFeature(
            feat_geom=x[0], reason=invalidReason, fields=fields
        )
        newNonVisitedFeatFunc = lambda x: self.createNewInvalidLineFeature(
            feat_geom=x[0], reason=nonVisitedReason, fields=fields
        )
        # add all non-validated features
        for line in nonValidatedLines:
            # create new feture
            feat = newNonVisitedFeatFunc([line.geometry(), line.id()])
            # add it to new features list
            featList.append(feat)
        # add invalid lines
        for lineId, line in invalidLinesDict.items():
            # create new feture
            feat = newInvalidFeatFunc([line.geometry(), lineId])
            # add it to new features list
            featList.append(feat)
        return featList

    def verifyNetworkDirectioning(
        self,
        networkLayer,
        networkNodeLayer,
        frame,
        searchRadius,
        waterBodyClasses=None,
        waterSinkLayer=None,
        spillwayLayer=None,
        ditchLayer=None,
        max_amount_cycles=1,
        attributeBlackList=None,
        feedback=None,
        selectValid=False,
        excludePrimaryKeys=True,
        ignoreVirtualFields=True,
    ):
        fieldList = self.layerHandler.getAttributesFromBlackList(
            networkLayer,
            attributeBlackList=attributeBlackList,
            ignoreVirtualFields=ignoreVirtualFields,
            excludePrimaryKeys=excludePrimaryKeys,
        )
        waterBodyClasses = [] if waterBodyClasses is None else waterBodyClasses
        # update createNetworkNodesProcess object node dictionary
        stepCount = 0
        if feedback is not None:
            multiStepFeedback = QgsProcessingMultiStepFeedback(
                max_amount_cycles, feedback
            )
            multiStepFeedback.setCurrentStep(stepCount)
        else:
            multiStepFeedback = None
        self.nodesToPop = []
        self.reclassifyNodeType = dict()
        if feedback is not None:
            multiStepFeedback.pushInfo("Identifying nodes...")
            multiStepFeedback.setCurrentStep(stepCount)
            stepCount += 1
        self.nodeDict = self.identifyAllNodes(
            networkLayer=networkLayer, feedback=multiStepFeedback
        )
        if feedback is not None:
            multiStepFeedback.pushInfo("Getting auxiliar spatial indexes...")
            multiStepFeedback.setCurrentStep(stepCount)
            stepCount += 1
        auxIndexStructure = self.getAuxIndexStructure(
            networkLayer,
            waterBodiesLayers=waterBodyClasses,
            waterSinkLayer=waterSinkLayer,
            spillwayLayer=spillwayLayer,
            ditchLayer=ditchLayer,
            feedback=multiStepFeedback,
        )
        networkLayerGeomType = networkLayer.geometryType()
        networkLayer.startEditing()
        networkNodeLayer.startEditing()
        # declare reclassification function from createNetworkNodesProcess object - parameter is [node, nodeTypeDict]
        self.classifyNode = lambda x: self.nodeType(
            nodePoint=x[0],
            networkLayer=networkLayer,
            frameLyrContourList=frame,
            waterBodiesLayers=waterBodyClasses,
            searchRadius=searchRadius,
            waterSinkLayer=waterSinkLayer,
            spillwayLayer=spillwayLayer,
            nodeTypeDict=x[1],
            networkLayerGeomType=networkLayerGeomType,
            ditchLayer=ditchLayer,
            fieldList=fieldList,
            auxIndexStructure=auxIndexStructure,
        )
        if feedback is not None:
            multiStepFeedback.pushInfo("Getting node type dictionary...")
            multiStepFeedback.setCurrentStep(stepCount)
            stepCount += 1
        self.nodeTypeDict, self.nodeIdDict = self.getNodeTypeDictFromNodeLayer(
            networkNodeLayer=networkNodeLayer, feedback=multiStepFeedback
        )
        # initiate nodes, invalid/valid lines dictionaries
        nodeFlags, inval, val = dict(), dict(), dict()
        # cycle count start
        # get max amount of orientation cycles
        max_amount_cycles = max_amount_cycles if max_amount_cycles > 0 else 1
        # validation method FINALLY starts...
        # to speed up modifications made to layers
        networkNodeLayer.beginEditCommand("Reclassify Nodes")
        networkLayer.beginEditCommand("Flip/Merge Lines")
        cycleCount = 0
        while True:
            if feedback is not None:
                multiStepFeedback.pushInfo("Starting cycle {0}...".format(cycleCount))
                multiStepFeedback.setCurrentStep(stepCount)
                stepCount += 1
            nodeFlags_, inval_, val_ = self.directNetwork(
                networkLayer=networkLayer, nodeLayer=networkNodeLayer
            )
            cycleCount += 1
            # Log amount of cycles completed
            cycleCountLog = self.tr("Cycle {0}/{1} completed.").format(
                cycleCount, max_amount_cycles
            )
            if feedback is not None:
                multiStepFeedback.pushInfo(cycleCountLog)
                multiStepFeedback.setCurrentStep(cycleCount)
            self.reclassifyNodeType = dict()
            # stop conditions: max amount of cycles exceeded, new flags is the same as previous flags (there are no new issues) and no change
            # change to valid lines list was made (meaning that the algorithm did not change network state) or no flags found
            if (
                (cycleCount == max_amount_cycles)
                or (not nodeFlags_)
                or (set(nodeFlags.keys()) == set(nodeFlags_.keys()) and val == val_)
            ):
                # copy values to final dict
                nodeFlags, inval, val = nodeFlags_, inval_, val_
                # no more modifications to those layers will be done
                networkLayer.endEditCommand()
                networkNodeLayer.endEditCommand()
                # try to load auxiliary line layer to fill it with invalid lines
                featList = self.getFlagLines(networkLayer, val, inval)
                invalidLinesLog = self.tr(
                    "Invalid lines were exposed in line flags layer."
                )
                if feedback is not None:
                    multiStepFeedback.pushInfo(invalidLinesLog)
                    multiStepFeedback.setCurrentStep(max_amount_cycles)
                vLines = val.keys()
                iLines = inval.keys()
                intersection = set(vLines) & set(iLines)
                if intersection:
                    map(val.pop, intersection)
                    # remove unnecessary variables
                    del vLines, iLines, intersection
                break
            # for the next iterations
            nodeFlags, inval, val = nodeFlags_, inval_, val_
            # pop all nodes to be popped and reset list
            for node in self.nodesToPop:
                # those were nodes connected to lines that were merged and now are no longer to be used
                self.nodeDict.pop(node, None)
                self.nodeDict.pop(node, None)
            self.nodesToPop = []
        if selectValid:
            networkLayer.selectByIds(list(val.keys()))
        if feedback is not None:
            percValid = (
                float(len(val)) * 100.0 / float(networkLayer.featureCount())
                if networkLayer.featureCount()
                else 0
            )
            if nodeFlags:
                msg = self.tr(
                    "{0} nodes may be invalid ({1:.2f}"
                    + "% of network is well directed). Check flags."
                ).format(len(nodeFlags), percValid)
            else:
                msg = self.tr("{1:.2f}" + "% of network is well directed.").format(
                    len(nodeFlags), percValid
                )
            multiStepFeedback.pushInfo(msg)
        return nodeFlags, featList, self.nodeIdDict

    def getFlagLines(self, networkLayer, val, inval):
        # get non-validated lines and add it to invalid lines layer as well
        nonValidatedLines = set()
        for line in networkLayer.getFeatures():
            lineId = line.id()
            if lineId in val or lineId in inval:
                # ignore if line are validated
                continue
            nonValidatedLines.add(line)
        featList = self.getAuxiliaryLines(
            fields=self.getFlagFields(),
            invalidLinesDict=inval,
            nonValidatedLines=nonValidatedLines,
            networkLayerName=networkLayer.name(),
        )
        return featList

    def mergeNetworkLines(self, line_a, line_b, layer):
        """
        Merge 2 lines of the same layer (it is assumed that they share the same set od attributes - except for ID and geometry).
        In case sets are different, the set of attributes from line_a will be kept. If geometries don't touch, method is not applicable.
        :param line_a: (QgsFeature) main line of merging process.
        :param line_b: (QgsFeature) line to be merged to line_a.
        :param layer: (QgsVectorLayer) layer containing given lines.
        :return: (bool) True if method runs OK or False, if lines do not touch.
        """
        # check if original layer is a multipart
        isMulti = QgsWkbTypes.isMultiType(layer.wkbType())
        # retrieve lines geometries
        geometry_a = line_a.geometry()
        geometry_b = line_b.geometry()
        # checking the spatial predicate touches
        if geometry_a.touches(geometry_b):
            # this generates a multi geometry
            geometry_a = geometry_a.combine(geometry_b)
            # this make a single line string if the multi geometries are neighbors
            geometry_a = geometry_a.mergeLines()
            if isMulti:
                # making a "single" multi geometry (EDGV standard)
                geometry_a.convertToMultiType()
            # updating feature
            line_a.setGeometry(geometry_a)
            # remove the aggregated line to avoid overlapping
            layer.deleteFeature(line_b.id())
            # updating layer
            layer.updateFeature(line_a)
            return True
        return False

    def getFlagFields(self):
        fields = QgsFields()
        fields.append(QgsField("reason", QVariant.String))
        return fields

    def createNewInvalidLineFeature(self, feat_geom, reason, fields):
        """
        Creates a new feature to be added to invalid lines layer.
        :param feat_geom: (QgsGeometry)
        :param reason: (str) reason of line invalidation.
        :param fields: (QgsFields) object containing all fields from layer.
        :return: (QgsFeature) new feature.
        """
        # set attribute map and create new feture
        feat = QgsFeature(fields)
        # set geometry
        feat.setGeometry(feat_geom)
        return feat
