from __future__ import absolute_import
import ast
import urlparse

from PyQt4.QtCore import QCoreApplication
from qgis.core import QgsRasterLayer, QgsVectorLayer, QgsMessageLog, QgsMapLayerRegistry, QgsProject
from qgis.gui import QgsMessageBar
from qgis.utils import iface

from .plugin_settings import PluginSettings
from .supported_drivers import KNOWN_DRIVERS
from .py_tiled_layer.tiles import TileServiceInfo
from .py_tiled_layer.tilelayer import TileLayer

service_layers = []

def tr(message):
    # noinspection PyTypeChecker,PyArgumentList,PyCallByClass
    # return QCoreApplication.translate('QuickMapServices', message)
    return message

def add_layer_to_map(ds):
    layers4add = []

    if ds.type.lower() == KNOWN_DRIVERS.TMS.lower():
        service_info = TileServiceInfo(tr(ds.alias), ds.copyright_text, ds.tms_url)
        service_info.zmin = ds.tms_zmin or service_info.zmin
        service_info.zmax = ds.tms_zmax or service_info.zmax
        if ds.tms_y_origin_top is not None:
            service_info.yOriginTop = ds.tms_y_origin_top
        service_info.epsg_crs_id = ds.tms_epsg_crs_id
        service_info.postgis_crs_id = ds.tms_postgis_crs_id
        service_info.custom_proj = ds.tms_custom_proj

        if ds.tms_tile_ranges is not None: # needs try block & checks that keys are integers etc..
            service_info.tile_ranges = ast.literal_eval(ds.tms_tile_ranges)
        if ds.tms_tsize1 is not None:
            service_info.tsize1 = ds.tms_tsize1
        if ds.tms_origin_x is not None:
            service_info.originX = ds.tms_origin_x
        if ds.tms_origin_y is not None:
            service_info.originY = ds.tms_origin_y

        layer = TileLayer(service_info, False)
        layers4add.append(layer)
    if ds.type.lower() == KNOWN_DRIVERS.GDAL.lower():
        layer = QgsRasterLayer(ds.gdal_source_file, tr(ds.alias))
        layers4add.append(layer)
    if ds.type.lower() == KNOWN_DRIVERS.WMS.lower():
        qgis_wms_uri = u''
        if ds.wms_params:
            qgis_wms_uri += ds.wms_params
        if ds.wms_layers:
            layers = ds.wms_layers.split(',')
            if layers:
                if ds.wms_turn_over:
                    layers.reverse()
                qgis_wms_uri += '&layers=' + '&layers='.join(layers) + '&styles=' * len(layers)
        qgis_wms_uri += '&url=' + ds.wms_url

        layer = QgsRasterLayer(qgis_wms_uri, tr(ds.alias), KNOWN_DRIVERS.WMS.lower())
        layers4add.append(layer)
    if ds.type.lower() == KNOWN_DRIVERS.WFS.lower():
        qgis_wfs_uri_base = ds.wfs_url

        if ds.wfs_params is not None:
            qgis_wfs_uri_base += ds.wfs_params

        o = urlparse.urlparse(qgis_wfs_uri_base)
        request_attrs = dict(urlparse.parse_qsl(o.query))
        
        new_request_attrs = {}
        for k, v in request_attrs.items():
            new_request_attrs[k.upper()] = v

        if ds.wfs_epsg is not None:
            new_request_attrs['SRSNAME'] = "EPSG:{0}".format(ds.wfs_epsg)

        layers = []
        if len(ds.wfs_layers) > 0:
            layers.extend(ds.wfs_layers)
        else:
            layers_str = request_attrs.get('TYPENAME', '')
            layers.extend(layers_str.split())

        for layer_name in layers:
            new_request_attrs['TYPENAME'] = layer_name

            url_parts = list(o)
            url_parts[4] = "&".join(
                ["%s=%s" % (k, v) for k, v in new_request_attrs.items()]
            )

            qgis_wfs_uri = urlparse.urlunparse(url_parts)
            layer = QgsVectorLayer(
                qgis_wfs_uri,
                "%s - %s" % (tr(ds.alias), layer_name),
                "WFS")
            layers4add.append(layer)

    if ds.type.lower() == KNOWN_DRIVERS.GEOJSON.lower():
        layer = QgsVectorLayer(
            ds.geojson_url,
            tr(ds.alias),
            "ogr")
        layers4add.append(layer)

    for layer in layers4add:
        if not layer.isValid():
            error_message = tr('Layer %s can\'t be added to the map!') % ds.alias
            iface.messageBar().pushMessage(tr('Error'),
                                           error_message,
                                           level=QgsMessageBar.CRITICAL)
            QgsMessageLog.logMessage(error_message, level=QgsMessageLog.CRITICAL)
        else:
            # Set attribs
            layer.setAttribution(ds.copyright_text)
            layer.setAttributionUrl(ds.copyright_link)
            # Insert layer
            toc_root = QgsProject.instance().layerTreeRoot()

            selected_node = iface.layerTreeView().currentNode()
            if selected_node.nodeType() == selected_node.NodeGroup:
                toc_root =  selected_node
            
            if ds.type.lower() in (KNOWN_DRIVERS.WMS.lower(), KNOWN_DRIVERS.TMS.lower()):
                position = len(toc_root.children())  # Insert to bottom if wms\tms
            else:
                position = 0  # insert to top
            QgsMapLayerRegistry.instance().addMapLayer(layer, False)
            toc_root.insertLayer(position, layer)

            # Save link
            service_layers.append(layer)
            # Set OTF CRS Transform for map
            if PluginSettings.enable_otf_3857() and ds.type == KNOWN_DRIVERS.TMS:
                iface.mapCanvas().setCrsTransformEnabled(True)
                iface.mapCanvas().setDestinationCrs(TileLayer.CRS_3857)