# -*- coding: utf-8 -*-
"""
/***************************************************************************
 PointCorrection
                                 A QGIS plugin
 Following corrections made to interpretation shape subclass number, interpretation fields are updated and correction field in point file is updated with new value and accuracy csv updated.
 Generated by Plugin Builder: http://g-sherman.github.io/Qgis-Plugin-Builder/
                              -------------------
        begin                : 2019-11-14
        git sha              : $Format:%H$
        copyright            : (C) 2019 by David Kerr
        email                : dk@tcarta.com
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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 pathlib import Path
import pandas as pd
import sys
import os.path

from qgis.PyQt.QtCore import QSettings, QTranslator, QCoreApplication
from qgis.PyQt.QtGui import QIcon
from qgis.PyQt.QtWidgets import QAction
from qgis.core import QgsProject, QgsVectorLayer, QgsVectorLayerJoinInfo, QgsProject, QgsExpression, Qgis, QgsField
from PyQt5.QtWidgets import QAbstractItemView, QAction, QMessageBox
from PyQt5.QtCore import QVariant

# Initialize Qt resources from file resources.py
from .resources import *
# Import the code for the dialog
from .point_correction_dialog import PointCorrectionDialog

BASE_DIR = Path(__file__).resolve().parent
CSV = BASE_DIR.joinpath('csv/classes.csv')
CSV_POINTS = BASE_DIR.joinpath('csv/classes_for_points.csv')
CSV_AREAS = BASE_DIR.joinpath('csv/hatitat_tile_intersection_areas.csv')
RULE_CSV = BASE_DIR.joinpath('csv/ruleID.csv')


class PointCorrection:
    """QGIS Plugin Implementation."""

    def __init__(self, iface):
        """Constructor.

        :param iface: An interface instance that will be passed to this class
            which provides the hook by which you can manipulate the QGIS
            application at run time.
        :type iface: QgsInterface
        """
        # Save reference to the QGIS interface
        self.iface = iface
        # initialize plugin directory
        self.plugin_dir = os.path.dirname(__file__)
        # initialize locale
        locale = QSettings().value('locale/userLocale')[0:2]
        locale_path = os.path.join(
            self.plugin_dir,
            'i18n',
            'PointCorrection_{}.qm'.format(locale))

        if os.path.exists(locale_path):
            self.translator = QTranslator()
            self.translator.load(locale_path)
            QCoreApplication.installTranslator(self.translator)

        # Declare instance attributes
        self.actions = []
        self.menu = self.tr(u'&Make Corrections to Point File')

        # Check if plugin was started the first time in current QGIS session
        # Must be set in initGui() to survive plugin reloads
        self.first_start = None

    # noinspection PyMethodMayBeStatic
    def tr(self, message):
        """Get the translation for a string using Qt translation API.

        We implement this ourselves since we do not inherit QObject.

        :param message: String for translation.
        :type message: str, QString

        :returns: Translated version of message.
        :rtype: QString
        """
        # noinspection PyTypeChecker,PyArgumentList,PyCallByClass
        return QCoreApplication.translate('PointCorrection', message)


    def add_action(
        self,
        icon_path,
        text,
        callback,
        enabled_flag=True,
        add_to_menu=True,
        add_to_toolbar=True,
        status_tip=None,
        whats_this=None,
        parent=None):
        """Add a toolbar icon to the toolbar.

        :param icon_path: Path to the icon for this action. Can be a resource
            path (e.g. ':/plugins/foo/bar.png') or a normal file system path.
        :type icon_path: str

        :param text: Text that should be shown in menu items for this action.
        :type text: str

        :param callback: Function to be called when the action is triggered.
        :type callback: function

        :param enabled_flag: A flag indicating if the action should be enabled
            by default. Defaults to True.
        :type enabled_flag: bool

        :param add_to_menu: Flag indicating whether the action should also
            be added to the menu. Defaults to True.
        :type add_to_menu: bool

        :param add_to_toolbar: Flag indicating whether the action should also
            be added to the toolbar. Defaults to True.
        :type add_to_toolbar: bool

        :param status_tip: Optional text to show in a popup when mouse pointer
            hovers over the action.
        :type status_tip: str

        :param parent: Parent widget for the new action. Defaults None.
        :type parent: QWidget

        :param whats_this: Optional text to show in the status bar when the
            mouse pointer hovers over the action.

        :returns: The action that was created. Note that the action is also
            added to self.actions list.
        :rtype: QAction
        """

        icon = QIcon(icon_path)
        action = QAction(icon, text, parent)
        action.triggered.connect(callback)
        action.setEnabled(enabled_flag)

        if status_tip is not None:
            action.setStatusTip(status_tip)

        if whats_this is not None:
            action.setWhatsThis(whats_this)

        if add_to_toolbar:
            # Adds plugin icon to Plugins toolbar
            self.iface.addToolBarIcon(action)

        if add_to_menu:
            self.iface.addPluginToMenu(
                self.menu,
                action)

        self.actions.append(action)

        return action

    def initGui(self):
        """Create the menu entries and toolbar icons inside the QGIS GUI."""

        icon_path = ':/plugins/point_correction/icon.png'
        self.add_action(
            icon_path,
            text=self.tr(u'Correction tool'),
            callback=self.run,
            parent=self.iface.mainWindow())

        # will be set False in run()
        self.first_start = True


    def unload(self):
        """Removes the plugin menu item and icon from QGIS GUI."""
        for action in self.actions:
            self.iface.removePluginMenu(
                self.tr(u'&Make Corrections to Point File'),
                action)
            self.iface.removeToolBarIcon(action)

    def check_if_file_is_shp(self, layer_shp):
        """Returns true if multipolygon shapefile"""
        shp = True
        if not layer_shp.geometryType() == 2:
            shp = False
        return shp

    def check_if_file_is_pt(self, layer_pt):
        """Returns true if point shapfile"""
        points = True
        if not layer_pt.geometryType() == 0:
            points = False
        return points


    def join_to_pt_and_extract(self, layer, pt_lyr):
        """Extract interpretation values to points"""
        shp = 'HabitatSub'
        pt = 'Correction'
        f = pt_lyr.fields().indexFromName(pt)
        f_ = layer.fields().indexFromName(shp)
        pt_lyr.startEditing()
        for feature_x in pt_lyr.getFeatures():
            for feature_y in layer.getFeatures():
                if feature_y.geometry().intersects(feature_x.geometry()):
                    pt_lyr.changeAttributeValue(feature_x.id(), f, feature_y[f_])
        pt_lyr.commitChanges()

    def calculate_stats(self, folder, layer_pt):
        csv = folder.joinpath(f'{layer_pt.name()}_accuracy.csv')
        print(csv)
        print(csv.exists())
        if not csv.exists():
            QMessageBox.critical(self.iface.mainWindow(),
                            f'Error! ',
                            f"Could not find {layer_pt.name()}_accuracy.csv in which to save statistics. Please put this csv in the same folder as the point and area shapefiles and rerun.")
        else:
            int_field = 'Correction'
            qc_field = 'QC_subnum'
            int_ = layer_pt.fields().indexFromName(int_field)
            qc = layer_pt.fields().indexFromName(qc_field)
            matching_values_counter = 0
            no_rows = layer_pt.featureCount()
            for feature in layer_pt.getFeatures():
                if feature[int_] == feature[qc]:
                    matching_values_counter += 1
            accuracy = (matching_values_counter/no_rows) * 100
            df = pd.read_csv(csv)
            df['Second_run_accuracy%'] = accuracy
            first_accuracy = df['First_run_accuracy%'].tolist()
            df.to_csv(csv, index=False)
            return accuracy, first_accuracy[0]

    def join_rule_id_to_shp(self, layer_shp):
        print('joining')
        ruleID_csv = QgsVectorLayer(f'file:///{str(RULE_CSV)}?delimiter=,','classes','delimitedtext')
        QgsProject.instance().addMapLayer(ruleID_csv)
        csv_field = 'HabitatSub'
        shp_field = 'HabitatSub'
        joinObject = QgsVectorLayerJoinInfo()
        joinObject.setJoinFieldName(shp_field)
        joinObject.setTargetFieldName(csv_field)
        joinObject.setJoinLayerId(ruleID_csv.id())
        joinObject.setUsingMemoryCache(True)
        joinObject.setJoinLayer(ruleID_csv)
        layer_shp.addJoin(joinObject)
        layer_shp.startEditing()
        field = QgsField('RuleID', QVariant.Int)
        if layer_shp.fields().indexFromName('RuleID') == -1:
            layer_shp.dataProvider().addAttributes([field])
            layer_shp.updateFields()
        idx = layer_shp.fields().indexFromName('RuleID')
        idx_join = layer_shp.fields().indexFromName('classes_RuleID_csv')
        print(idx_join)
        for feature in layer_shp.getFeatures():
            layer_shp.changeAttributeValue(feature.id(), idx, feature[idx_join])
            layer_shp.updateFields()
        #layer_shp.dataProvider().deleteAttributes([idx_join])
        layer_shp.commitChanges()
        layer_shp.removeJoin(ruleID_csv.id())
        QgsProject.instance().removeMapLayer(ruleID_csv)
        layer_shp.commitChanges()





    def fill_correction_field(self, layer_shp, layer_pt):
        filename = Path(layer_shp.source().split('|')[0]).resolve()
        if filename.exists():
            folder = filename.parent
            if self.check_if_file_is_shp(layer_shp) and self.check_if_file_is_pt(layer_pt):
                self.join_to_pt_and_extract(layer_shp, layer_pt)
                accuracy, first_accuracy = self.calculate_stats(folder, layer_pt)
                self.join_rule_id_to_shp(layer_shp)
                QMessageBox.information(self.iface.mainWindow(),
                                'Success',
                                f"Point shapefile saved successfully. Interpretation accuracy has changed from - {first_accuracy}% to {accuracy}%")

            else:
                QMessageBox.critical(self.iface.mainWindow(),
                            f'Error! ',
                            "The wrong shapefile formats have been loaded. Please try again.")

        else:
            QMessageBox.critical(self.iface.mainWindow(),
                            f'Error! Layer {layer_shp.name()} not saved',
                            "Please save the selected layer before continuing.")


    def run(self):
        """Run method that performs all the real work"""

        # Create the dialog with elements (after translation) and keep reference
        # Only create GUI ONCE in callback, so that it will only load when the plugin is started
        if self.first_start == True:
            self.first_start = False
            self.dlg = PointCorrectionDialog()

        layers = QgsProject.instance().layerTreeRoot().children()
        # Clear the contents of the comboBox from previous runs
        self.dlg.comboBox.clear()
        self.dlg.comboBox_2.clear()
        # Populate the comboBox with names of all the loaded layers
        self.dlg.comboBox.addItems([layer.name() for layer in layers])
        self.dlg.comboBox_2.addItems([layer.name() for layer in layers])
        # show the dialog
        self.dlg.show()
        # Run the dialog event loop
        result = self.dlg.exec_()
        # See if OK was pressed
        if result:
            selected_layer_index_shp = self.dlg.comboBox.currentIndex()
            selected_layer_shp = layers[selected_layer_index_shp].layer()
            selected_layer_index_pt = self.dlg.comboBox_2.currentIndex()
            selected_layer_pt = layers[selected_layer_index_pt].layer()
            self.fill_correction_field(selected_layer_shp, selected_layer_pt)
            
