# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

import sys
from pathlib import Path

from PySide6.QtCore import (QAbstractItemModel, QItemSelectionModel,
                            QModelIndex, Qt, Slot)
from PySide6.QtWidgets import (QAbstractItemView, QMainWindow, QTreeView,
                               QWidget)
from PySide6.QtTest import QAbstractItemModelTester

from treemodel import TreeModel


class MainWindow(QMainWindow):
    def __init__(self, parent: QWidget = None):
        super().__init__(parent)
        self.resize(573, 468)

        self.view = QTreeView()
        self.view.setAlternatingRowColors(True)
        self.view.setSelectionBehavior(QAbstractItemView.SelectItems)
        self.view.setHorizontalScrollMode(QAbstractItemView.ScrollPerPixel)
        self.view.setAnimated(False)
        self.view.setAllColumnsShowFocus(True)
        self.setCentralWidget(self.view)

        menubar = self.menuBar()
        file_menu = menubar.addMenu("&File")
        self.exit_action = file_menu.addAction("E&xit")
        self.exit_action.setShortcut("Ctrl+Q")
        self.exit_action.triggered.connect(self.close)

        actions_menu = menubar.addMenu("&Actions")
        actions_menu.triggered.connect(self.update_actions)
        self.insert_row_action = actions_menu.addAction("Insert Row")
        self.insert_row_action.setShortcut("Ctrl+I, R")
        self.insert_row_action.triggered.connect(self.insert_row)
        self.insert_column_action = actions_menu.addAction("Insert Column")
        self.insert_column_action.setShortcut("Ctrl+I, C")
        self.insert_column_action.triggered.connect(self.insert_column)
        actions_menu.addSeparator()
        self.remove_row_action = actions_menu.addAction("Remove Row")
        self.remove_row_action.setShortcut("Ctrl+R, R")
        self.remove_row_action.triggered.connect(self.remove_row)
        self.remove_column_action = actions_menu.addAction("Remove Column")
        self.remove_column_action.setShortcut("Ctrl+R, C")
        self.remove_column_action.triggered.connect(self.remove_column)
        actions_menu.addSeparator()
        self.insert_child_action = actions_menu.addAction("Insert Child")
        self.insert_child_action.setShortcut("Ctrl+N")
        self.insert_child_action.triggered.connect(self.insert_child)
        help_menu = menubar.addMenu("&Help")
        about_qt_action = help_menu.addAction("About Qt", qApp.aboutQt)
        about_qt_action.setShortcut("F1")

        self.setWindowTitle("Editable Tree Model")

        headers = ["Title", "Description"]

        file = Path(__file__).parent / "default.txt"
        self.model = TreeModel(headers, file.read_text(), self)

        if "-t" in sys.argv:
            QAbstractItemModelTester(self.model, self)
        self.view.setModel(self.model)
        self.view.expandAll()

        for column in range(self.model.columnCount()):
            self.view.resizeColumnToContents(column)

        selection_model = self.view.selectionModel()
        selection_model.selectionChanged.connect(self.update_actions)

        self.update_actions()

    @Slot()
    def insert_child(self) -> None:
        selection_model = self.view.selectionModel()
        index: QModelIndex = selection_model.currentIndex()
        model: QAbstractItemModel = self.view.model()

        if model.columnCount(index) == 0:
            if not model.insertColumn(0, index):
                return

        if not model.insertRow(0, index):
            return

        for column in range(model.columnCount(index)):
            child: QModelIndex = model.index(0, column, index)
            model.setData(child, "[No data]", Qt.EditRole)
            if not model.headerData(column, Qt.Horizontal):
                model.setHeaderData(column, Qt.Horizontal, "[No header]",
                                    Qt.EditRole)

        selection_model.setCurrentIndex(
            model.index(0, 0, index), QItemSelectionModel.ClearAndSelect
        )
        self.update_actions()

    @Slot()
    def insert_column(self) -> None:
        model: QAbstractItemModel = self.view.model()
        column: int = self.view.selectionModel().currentIndex().column()

        changed: bool = model.insertColumn(column + 1)
        if changed:
            model.setHeaderData(column + 1, Qt.Horizontal, "[No header]",
                                Qt.EditRole)

        self.update_actions()

    @Slot()
    def insert_row(self) -> None:
        index: QModelIndex = self.view.selectionModel().currentIndex()
        model: QAbstractItemModel = self.view.model()
        parent: QModelIndex = index.parent()

        if not model.insertRow(index.row() + 1, parent):
            return

        self.update_actions()

        for column in range(model.columnCount(parent)):
            child: QModelIndex = model.index(index.row() + 1, column, parent)
            model.setData(child, "[No data]", Qt.EditRole)

    @Slot()
    def remove_column(self) -> None:
        model: QAbstractItemModel = self.view.model()
        column: int = self.view.selectionModel().currentIndex().column()

        if model.removeColumn(column):
            self.update_actions()

    @Slot()
    def remove_row(self) -> None:
        index: QModelIndex = self.view.selectionModel().currentIndex()
        model: QAbstractItemModel = self.view.model()

        if model.removeRow(index.row(), index.parent()):
            self.update_actions()

    @Slot()
    def update_actions(self) -> None:
        selection_model = self.view.selectionModel()
        has_selection: bool = not selection_model.selection().isEmpty()
        self.remove_row_action.setEnabled(has_selection)
        self.remove_column_action.setEnabled(has_selection)

        current_index = selection_model.currentIndex()
        has_current: bool = current_index.isValid()
        self.insert_row_action.setEnabled(has_current)
        self.insert_column_action.setEnabled(has_current)

        if has_current:
            self.view.closePersistentEditor(current_index)
            msg = f"Position: ({current_index.row()},{current_index.column()})"
            if not current_index.parent().isValid():
                msg += " in top level"
            self.statusBar().showMessage(msg)