# -*- coding: utf-8 -*-
"""
/***************************************************************************
 DsgTools
                                 A QGIS plugin
 Brazilian Army Cartographic Production Tools
                              -------------------
        begin                : 2024-02-21
        git sha              : $Format:%H$
        copyright            : (C) 2024 by Philipe Borba - Cartographic Engineer @ Brazilian Army
        email                : borba.philipe@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.                                   *
 *                                                                         *
 ***************************************************************************/
"""

import copy
from dataclasses import asdict, dataclass, field
from enum import Enum, unique
import json
from pathlib import Path
from typing import Any, Callable, Dict, List, Optional
import os
from time import time
import tempfile

from qgis.core import (
    QgsTask,
    QgsProject,
    QgsMapLayer,
    QgsProcessingFeedback,
    QgsProcessingModelAlgorithm,
    QgsVectorLayer,
    QgsProcessingUtils,
    QgsProcessingContext,
    QgsMessageLog,
    Qgis,
    QgsVectorFileWriter,
)
from qgis.PyQt.QtCore import pyqtSignal, QObject
from qgis.utils import iface
from processing.tools import dataobjects
import processing


@unique
class ExecutionStatus(str, Enum):
    """Enumeration representing the execution status of a workflow item.

    Attributes:
        INITIAL: Initial state.
        RUNNING: Currently running.
        FAILED: Execution failed.
        CANCELED: Execution canceled.
        FINISHED: Execution finished successfully.
        FINISHED_WITH_FLAGS: Execution finished with flags raised.
        PAUSED_BEFORE_RUNNING: Execution paused before running.
        IGNORE_FLAGS: Flags are ignored for this step.
    """

    INITIAL = "initial"
    RUNNING = "running"
    FAILED = "failed"
    CANCELED = "canceled"
    FINISHED = "finished"
    FINISHED_WITH_FLAGS = "finished with flags"
    PAUSED_BEFORE_RUNNING = "paused before running"
    IGNORE_FLAGS = "ignore flags"


@dataclass
class FlagSettings:
    """Dataclass representing settings related to flags in a workflow item.

    Attributes:
        onFlagsRaised (str): Action to take when flags are raised - "halt", "warn", or "ignore".
        modelCanHaveFalsePositiveFlags (bool): Whether the model can have false positive flags.
        loadOutput (bool): Whether to load the output.
        flagLayerNames (List[str]): List of flag layer names.
    """

    onFlagsRaised: str
    modelCanHaveFalsePositiveFlags: bool
    loadOutput: bool
    flagLayerNames: List[str] = field(default_factory=[])

    def __post_init__(self):
        if self.onFlagsRaised not in ("halt", "warn", "ignore"):
            raise ValueError("Invalid on flags raised flag.")


@dataclass
class ModelSource:
    """Dataclass representing the source of a processing model.

    Attributes:
        type (str): Type of the model source.
        data (str): Data related to the model source.

    Methods:
        modelFromFile(filepath: str) -> QgsProcessingModelAlgorithm:
            Initiates a model from a filepath.

        modelFromXml() -> QgsProcessingModelAlgorithm:
            Creates a processing model object from XML text.
    """

    type: str
    data: str

    @staticmethod
    def modelFromFile(filepath):
        """
        Initiates a model from a filepath.
        :param filepath: (str) filepath for target file.
        :return: (QgsProcessingModelAlgorithm) model as a processing algorithm.
        """
        alg = QgsProcessingModelAlgorithm()
        alg.fromFile(filepath)
        alg.initAlgorithm()
        return alg

    def modelFromXml(self) -> QgsProcessingModelAlgorithm:
        """
        Creates a processing model object from XML text.
        :param xml: (str) XML file contents.
        :return: (QgsProcessingModelAlgorithm) model as a processing algorithm.
        """
        temp = os.path.join(
            os.path.dirname(__file__), "temp_model_{0}.model3".format(hash(time()))
        )
        with open(temp, "w+", encoding="utf-8") as xmlFile:
            xmlFile.write(self.data)
        alg = ModelSource.modelFromFile(temp)
        os.remove(temp)
        return alg


@dataclass
class Metadata:
    """Dataclass representing metadata for a workflow item.

    Attributes:
        originalName (str): The original name of the workflow item.
    """

    originalName: str


@dataclass
class ModelExecutionOutput:
    """Dataclass representing the output of a model execution.

    Attributes:
        result (Dict[str, Any]): Execution result.
        executionTime (float): Execution time in seconds.
        executionMessage (str): Message related to the execution.
        status (ExecutionStatus): Execution status.
    """

    result: Dict[str, Any] = field(default_factory=dict)
    executionTime: float = 0.0
    executionMessage: str = ""
    status: ExecutionStatus = ExecutionStatus.INITIAL

    def __post_init__(self):
        if isinstance(self.status, str):
            self.status = ExecutionStatus(self.status)
        if len(self.result) == 0:
            return
        for key, value in self.result.items():
            self.result[key] = self.loadGeojsonAsQgsVectorLayer(key, value)

    def as_dict(self):
        output_dict = {
            "executionTime": self.executionTime,
            "executionMessage": self.executionMessage,
            "status": self.status,
            "result": dict(),
        }
        for k, v in self.result.items():
            geojson_dict = self.getGeoJsonFromQgsVectorLayer(v)
            if geojson_dict == {}:
                continue
            output_dict["result"][k] = geojson_dict
        return output_dict

    def loadGeojsonAsQgsVectorLayer(self, layerName: str, data: dict) -> QgsVectorLayer:
        layer = QgsVectorLayer(json.dumps(data), layerName, "ogr")
        return layer

    def getGeoJsonFromQgsVectorLayer(self, lyr: QgsVectorLayer) -> dict:
        temp_geojson = tempfile.NamedTemporaryFile(suffix=".geojson", delete=False)
        temp_geojson.close()
        try:
            error = QgsVectorFileWriter.writeAsVectorFormat(
                lyr, temp_geojson.name, "utf-8", lyr.crs(), "GeoJSON"
            )
        except:
            return {}
        with open(temp_geojson.name, "r", encoding="utf-8") as f:
            geojson_content = f.read()
        Path(temp_geojson.name).unlink()
        return geojson_content


@dataclass
class DSGToolsWorkflowItem(QObject):
    """Class representing a workflow item in DSGTools.

    Attributes:
        displayName (str): Display name of the workflow item.
        flags (FlagSettings): Settings related to flags in the workflow item.
        pauseAfterExecution (bool): Whether to pause after execution.
        source (ModelSource): Source of the processing model.
        metadata (Metadata): Metadata related to the workflow item.

    Signals:
        workflowItemExecutionFinished: Emitted when the workflow item execution is finished.
    """

    displayName: str
    flags: FlagSettings
    pauseAfterExecution: bool
    source: ModelSource
    metadata: Metadata
    tooltip: str = ""

    workflowItemExecutionFinished = pyqtSignal(object)

    def __post_init__(self):
        """Initialize post dataclass creation."""
        super().__init__()
        self.feedback = QgsProcessingFeedback()
        self.context = dataobjects.createContext(feedback=self.feedback)
        self.context.setProject(QgsProject.instance())
        self.resetItem()
        if self.tooltip == "" and self.model.shortDescription != "":
            self.tooltip = self.model.shortDescription()

    def resetItem(self):
        """Reset the workflow item."""
        self.currentTask = None
        if hasattr(self, "executionOutput"):
            self.clearOutputs()
        self.executionOutput = ModelExecutionOutput()
        self.feedback.setProgress(0)
        self.model = self.getModel()

    def as_dict(self) -> Dict[str, str]:
        """Convert the workflow item to a dictionary."""
        return {
            k: v
            for k, v in asdict(self).items()
            if k not in ["workflowItemExecutionFinished"]
        }

    def setStatusFromDict(self, data: dict[str, Any]):
        self.executionOutput = ModelExecutionOutput(**data)

    def executionStatusAsDict(self):
        d = self.executionOutput.as_dict()
        # d.pop("result")
        return d

    def getModel(self) -> QgsProcessingModelAlgorithm:
        """Get the processing model from the source.

        Returns:
            QgsProcessingModelAlgorithm: The processing model.
        """
        return self.source.modelFromXml()

    def getModelParameters(self) -> List[str]:
        """Get the parameters of the processing model.

        Returns:
            List[str]: List of parameter names.
        """
        if self.model is None:
            return []
        return [param.name() for param in self.model.parameterDefinitions()]

    def getFlagNames(self) -> List[str]:
        """Get the names of flag layers.

        Returns:
            List[str]: List of flag layer names.
        """
        return self.flags.flagLayerNames

    def getAllOutputNamesFromModel(self) -> List[str]:
        return [
            outputDef.name().split(":")[-1]
            for outputDef in self.model.outputDefinitions()
        ]

    def flagsCanHaveFalsePositiveResults(self) -> bool:
        return self.flags.modelCanHaveFalsePositiveFlags

    def getDescription(self) -> str:
        return (
            self.model.shortDescription()
            if self.tooltip in ("", None)
            else self.tooltip
        )

    def getOutputFlags(self):
        """Get the output flags."""
        pass

    def getTask(self) -> QgsTask:
        """Prepare the task for the workflow item execution.

        Args:
            feedback (QgsProcessingFeedback): Feedback for the task.

        Returns:
            QgsTask: The prepared task.
        """
        func = self.getTaskRunningFunction()
        on_finished_func = self.getOnFinishedFunction()
        self.currentTask = QgsTask.fromFunction(
            self.model.name(),
            func,
            on_finished=on_finished_func,
        )
        return self.currentTask

    def pauseBeforeRunning(self):
        """Pause the workflow item before running."""
        self.executionOutput = ModelExecutionOutput(
            executionMessage=self.tr(
                f"Workflow item {self.displayName} execution paused by previous step."
            ),
            status=ExecutionStatus.PAUSED_BEFORE_RUNNING,
        )

    def setCurrentStateToIgnoreFlags(self):
        """Set the status to ignore flags on the current workflow step."""
        if not self.flagsCanHaveFalsePositiveResults():
            return
        if self.executionOutput.status == ExecutionStatus.IGNORE_FLAGS:
            self.changeCurrentStatus(
                status=ExecutionStatus.FINISHED_WITH_FLAGS,
                executionMessage=self.tr(
                    f"Workflow item {self.displayName} status changed from ignore flags to finished with flags."
                ),
            )
            return
        self.changeCurrentStatus(
            status=ExecutionStatus.IGNORE_FLAGS,
            executionMessage=self.tr(
                f"Workflow item {self.displayName} flags were ignored by the user."
            ),
        )
        # não emite sinal pois esse passo é feito fora da execução.

    def changeCurrentStatus(
        self,
        status: ExecutionStatus,
        executionMessage: Optional[str] = None,
        executionTime: Optional[float] = None,
    ) -> None:
        """Change the current status of the workflow item.

        Args:
            status (ExecutionStatus): The new status.
            executionMessage (str): Message related to the status change.
        """
        self.executionOutput.status = (
            status if isinstance(status, ExecutionStatus) else ExecutionStatus(status)
        )
        self.executionOutput.executionMessage = (
            executionMessage if executionMessage is not None else ""
        )
        if executionTime is not None:
            self.executionOutput.executionTime = executionTime

    def cancelCurrentTask(self):
        """Cancel the current task."""
        if self.currentTask is None:
            return
        try:
            self.currentTask.cancel()
        except:
            pass
        self.currentTask = None
        self.changeCurrentStatus(
            status=ExecutionStatus.CANCELED,
            executionMessage=self.tr(
                f"Workflow item {self.displayName} canceled by user."
            ),
        )

    def getTaskRunningFunction(self) -> Callable:
        """Get the function to run for the task.

        Args:
            feedback (QgsProcessingFeedback): Feedback for the task.

        Returns:
            Callable: The function to run for the task.
        """
        modelParameters = self.getModelParameters()
        self.feedback.setProgress(0)

        def func(obj=None):
            start = time()
            out = processing.run(
                self.model,
                {param: "memory:" for param in modelParameters},
                feedback=self.feedback,
            )
            out.pop("CHILD_INPUTS", None)
            out.pop("CHILD_RESULTS", None)
            out["start_time"] = start
            return out

        return func

    def getOnFinishedFunction(self) -> Callable:
        """Get the function to run when the task is finished.

        Args:
            feedback (QgsProcessingFeedback): Feedback for the task.

        Returns:
            Callable: The function to run when the task is finished.
        """

        def on_finished_func(exception, result=None):
            if exception is not None:
                QgsMessageLog.logMessage(
                    f"Exception: {exception}",
                    "DSGTools Plugin",
                    Qgis.MessageLevel.Critical,
                )
                self.executionOutput = ModelExecutionOutput(
                    executionMessage=self.tr(
                        f"Workflow item {self.displayName} execution has failed:\n {str(exception)}"
                    ),
                    status=ExecutionStatus.FAILED,
                )
                self.workflowItemExecutionFinished.emit(self)
                return
            if result is not None:
                self.handleOutputs(result, self.feedback)
                self.loadOutputs(self.feedback)
                status = (
                    ExecutionStatus.FINISHED_WITH_FLAGS
                    if any(
                        lyr.featureCount() > 0
                        for k, lyr in self.executionOutput.result.items()
                        if lyr.name() in self.flags.flagLayerNames
                    )
                    else ExecutionStatus.FINISHED
                )
                statusMsg = (
                    self.tr("finished with flags.")
                    if status == ExecutionStatus.FINISHED_WITH_FLAGS
                    else self.tr("finished.")
                )
                self.changeCurrentStatus(
                    status=status,
                    executionMessage=self.tr(
                        f"Workflow item {self.displayName} {statusMsg}"
                    ),
                )
                self.feedback.setProgress(100)
            else:
                self.executionOutput = ModelExecutionOutput(
                    executionMessage=self.tr(
                        f"Workflow item {self.displayName} execution was canceled by the user."
                    ),
                    status=ExecutionStatus.CANCELED,
                )
            self.currentTask = None
            self.workflowItemExecutionFinished.emit(self)

        return on_finished_func

    def handleOutputs(self, result, feedback):
        """Handle the outputs of the task.

        Args:
            result: The result of the task.
            feedback (QgsProcessingFeedback): Feedback for the task.
        """
        start = result.pop("start_time")
        context = dataobjects.createContext(feedback=feedback)
        context.setProject(QgsProject.instance())
        for paramName, vl in result.items():
            baseName = paramName.rsplit(":", 1)[-1]
            name = baseName
            idx = 1
            while name in self.executionOutput.result:
                name = "{0} ({1})".format(baseName, idx)
                idx += 1
            if isinstance(vl, str):
                vl = QgsProcessingUtils.mapLayerFromString(vl, context)
            vl.setName(name)
            self.executionOutput.result[name] = vl
        self.executionOutput.executionTime = time() - start

    def loadOutput(self) -> bool:
        """Check if output loading is enabled.

        Returns:
            bool: True if output loading is enabled, False otherwise.
        """
        return self.flags.loadOutput

    def getStatus(self) -> ExecutionStatus:
        """Get the current status of the workflow item.

        Returns:
            ExecutionStatus: The current status.
        """
        return self.executionOutput.status

    def loadOutputs(self, feedback):
        """Load the outputs of the workflow item.

        Args:
            feedback (QgsProcessingFeedback): Feedback for the task.
        """
        loadOutput = self.loadOutput()
        flagLayerNames = self.flags.flagLayerNames
        context = QgsProcessingContext()
        iface.mapCanvas().freeze(True)
        layerAdded = False
        for name, vl in self.executionOutput.result.items():
            if vl is None:
                continue
            if vl.name() not in flagLayerNames and not loadOutput:
                continue
            if isinstance(vl, str):
                vl = QgsProcessingUtils.mapLayerFromString(vl, context)
                self.executionOutput.result[name] = vl
            if not isinstance(vl, QgsMapLayer) or not vl.isValid():
                continue
            vl.setName(name.split(":", 2)[-1])
            if vl.name() in flagLayerNames and vl.featureCount() == 0:
                continue
            cloneVl = vl.clone()
            self.executionOutput.result[cloneVl.name()] = cloneVl
            self.addLayerToGroup(
                cloneVl, self.displayName, clearGroupBeforeAdding=not layerAdded
            )
            self.enableFeatureCount(cloneVl)
            layerAdded = True
        iface.mapCanvas().freeze(False)

    def addLayerToGroup(self, layer, subgroupname, clearGroupBeforeAdding=False):
        """Add a layer to a group in the layer panel.

        Args:
            layer (QgsMapLayer): The layer to be added.
            subgroupname (str): Name for the subgroup to be added.
            clearGroupBeforeAdding (bool): Whether to clear the group before adding the layer.
        """
        subGroup = self.createGroups(subgroupname)
        if clearGroupBeforeAdding:
            self.clearGroup(subGroup)
        layer = (
            layer
            if isinstance(layer, QgsMapLayer)
            else QgsProcessingUtils.mapLayerFromString(layer)
        )
        QgsProject.instance().addMapLayer(layer, addToLegend=False)
        subGroup.addLayer(layer)

    def clearOutputs(self, onlyFlags=False):
        lyrKeysToPop = []
        iface.mapCanvas().freeze(True)
        for lyrName, vl in self.executionOutput.result.items():
            if onlyFlags and lyrName not in self.flags.flagLayerNames:
                continue
            try:
                QgsProject.instance().removeMapLayer(vl.id())
            except:
                pass
            lyrKeysToPop.append(lyrName)
        for key in lyrKeysToPop:
            self.executionOutput.result.pop(key)
        iface.mapCanvas().freeze(False)

    def createGroups(self, subgroupname):
        """Create groups in the layer panel.

        Args:
            subgroupname (str): Name for the subgroup to be created.

        Returns:
            QgsLayerTreeGroup: The created subgroup.
        """
        rootNode = QgsProject.instance().layerTreeRoot()
        parentGroupName = "DSGTools_QA_Toolbox"
        parentGroupNode = rootNode.findGroup(parentGroupName)
        parentGroupNode = (
            parentGroupNode
            if parentGroupNode
            else rootNode.insertGroup(0, parentGroupName)
        )
        subGroup = self.createGroup(subgroupname, parentGroupNode)
        return subGroup

    def createGroup(self, groupName, rootNode):
        """Create a group in the layer panel.

        Args:
            groupName (str): Name for the group.
            rootNode (QgsLayerTree): The root node for the group.

        Returns:
            QgsLayerTreeGroup: The created group.
        """
        groupNode = rootNode.findGroup(groupName)
        return groupNode if groupNode else rootNode.addGroup(groupName)

    def prepareGroup(self, model):
        """Prepare the group for the layer panel.

        Args:
            model: The model to be prepared.
        """
        subGroup = self.createGroups(self.model().model.displayName())
        self.clearGroup(subGroup)

    def clearGroup(self, group):
        """Clear a group in the layer panel.

        Args:
            group (QgsLayerTreeGroup): The group to be cleared.
        """
        for lyrGroup in group.findLayers():
            lyr = lyrGroup.layer()
            if isinstance(lyr, QgsVectorLayer):
                lyr.rollBack()
        group.removeAllChildren()

    def enableFeatureCount(self, lyr):
        root = QgsProject.instance().layerTreeRoot()
        lyrNode = root.findLayer(lyr.id())
        lyrNode.setCustomProperty("showFeatureCount", True)


def load_from_json(input_dict: dict) -> DSGToolsWorkflowItem:
    """Load a DSGToolsWorkflowItem from a JSON-like dictionary.

    Args:
        input_dict (dict): The dictionary containing the information for the workflow item.

    Returns:
        DSGToolsWorkflowItem: The loaded DSGToolsWorkflowItem.
    """
    params = copy.deepcopy(input_dict)
    params["flags"] = FlagSettings(**params["flags"])
    params["source"] = ModelSource(**params["source"])
    params["metadata"] = Metadata(**params["metadata"])
    return DSGToolsWorkflowItem(**params)
