import sys
import typing

import pandas as pd
from PyQt6 import uic, QtGui, QtCore
from PyQt6.QtCore import Qt, QSortFilterProxyModel
from PyQt6.QtGui import QPixmap, QAction
from PyQt6.QtWidgets import QMainWindow, QPushButton, QHBoxLayout, QLabel, \
    QVBoxLayout, QMenu, QApplication, QTableView, QListView


class PandasModel(QtCore.QAbstractTableModel):
    def __init__(self, df: pd.DataFrame, parent=None):
        QtCore.QAbstractTableModel.__init__(self, parent)
        self._data = df

        self._horizontalHeaders = [''] * len(df.columns)

        for i, column in enumerate(df.columns):
            self.setHeaderData(i, Qt.Orientation.Horizontal, column)

    def setHeaderData(self, section, orientation, data,
                      role=Qt.ItemDataRole.EditRole):

        if ((orientation == Qt.Orientation.Horizontal)
                and ((role == Qt.ItemDataRole.DisplayRole)
                     or (role == Qt.ItemDataRole.EditRole))):

            self._horizontalHeaders[section] = data
            return True
        else:
            return super().setHeaderData(section, orientation, data, role)

    def headerData(self, section, orientation,
                   role=Qt.ItemDataRole.DisplayRole):

        if (orientation == Qt.Orientation.Horizontal
                and role == Qt.ItemDataRole.DisplayRole):

            return self._horizontalHeaders[section]
        else:
            return super().headerData(section, orientation, role)

    def rowCount(self, parent=None):
        return len(self._data.values)

    def columnCount(self, parent=None):
        return self._data.columns.size

    def data(self, index, role=Qt.ItemDataRole.DisplayRole):
        if not index.isValid():
            return QtCore.QVariant()
        if role != Qt.ItemDataRole.DisplayRole:
            return QtCore.QVariant()

        item = self._data.iloc[index.row()].iloc[index.column()]

        if type(item) is pd.Timestamp:
            return QtCore.QVariant(item.strftime('%Y-%m-%d'))
        else:
            return QtCore.QVariant(str(item))


class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
        uic.loadUi("res/main_window.ui", self)
        self.setContentsMargins(9, 9, 9, 9)

        self._warning_layout \
            = self.findChild(QVBoxLayout, "warningLayout")

        self._create_button \
            = self.findChild(QPushButton, "createCategoryButton")
        self._delete_button \
            = self.findChild(QPushButton, "deleteCategoryButton")
        self._apply_button \
            = self.findChild(QPushButton, "applyCategoryButton")

        self._list_view \
            = self.findChild(QListView, "categoryListView")

        self._table_view \
            = self.findChild(QTableView, "transactionTableView")

        self._category_model = QtGui.QStandardItemModel()
        self._list_view.setModel(self._category_model)

        self._create_button.clicked.connect(
            self._handle_create_click)

        header = self._table_view.horizontalHeader()
        header.setContextMenuPolicy(Qt.ContextMenuPolicy.CustomContextMenu)
        header.customContextMenuRequested.connect(self._header_right_clicked)

    def add_warning_text(self, text: str):
        layout = QHBoxLayout()

        warningIcon = QLabel()
        pixmap = QPixmap("res/warning.png")
        warningIcon.setPixmap(pixmap)

        label = QLabel(text)
        label.setWordWrap(True)

        layout.addWidget(warningIcon)
        layout.addWidget(label)

        layout.setStretch(0, 0)
        layout.setStretch(1, 1)

        self._warning_layout.addLayout(layout)

    def set_statement_data(self, df: pd.DataFrame):
        model = PandasModel(df)
        proxyModel = QSortFilterProxyModel(self)
        proxyModel.setSourceModel(model)
        self._table_view.setModel(proxyModel)

        self._table_view.resizeColumnsToContents()

    def add_categories(self, categories: typing.Sequence[str]):
        for category in categories:
            item = QtGui.QStandardItem(category)
            self._category_model.appendRow(item)

    def _header_right_clicked(self, pos):
        context = QMenu(self)
        context.addAction(QAction("test 1", self))
        context.addAction(QAction("test 2", self))
        context.addAction(QAction("test 3", self))
        context.exec(self.sender().mapToGlobal(pos))

    def _handle_create_click(self):
        self.add_categories(['asdf'])

    def _handle_delete_click(self):
        pass

    def _handle_apply_click(self):
        pass


def show_main_window(categories: typing.Sequence[str] = None,
                     df: pd.DataFrame = None):
    app = QApplication(sys.argv)
    window = MainWindow()

    if categories is not None:
        window.add_categories(categories)

    if df is not None:
        window.set_statement_data(df)

    window.add_warning_text("The column 't' does not exist. Please rename the"
                            " column containing the dates of the transactions"
                            " to 't'.")
    window.add_warning_text("The column 'balance' does not exist. Please"
                            " rename the column containing the balance after"
                            " each transaction to 'balance'")
    window.add_warning_text("The column 'value' does not exist. Please rename"
                            " the column containing the values of the"
                            " transactions to 'value'.")

    window.show()
    app.exec()


def main():
    from banking_breakdown.statement_parser import get_stripped_statement
    import os
    os.chdir("../")

    categories = ["Food", "Rent & Utilities", "Hobbies", "Education",
                  "Transportation", "Social Life", "Other"]

    df = pd.read_csv("res/bank_statement_2023.csv", delimiter=';')
    # df = get_stripped_statement("res/bank_statement_2023.csv")

    show_main_window(categories, df)


if __name__ == "__main__":
    main()