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

from PySide6.QtCore import (QCoreApplication, QDir, QRegularExpression, Qt,
                            Property, Slot)
from PySide6.QtGui import QRegularExpressionValidator
from PySide6.QtWidgets import (QComboBox, QDialog, QDialogButtonBox,
                               QFormLayout, QGroupBox, QHBoxLayout,
                               QInputDialog, QLineEdit, QListWidget,
                               QListWidgetItem, QPushButton, QVBoxLayout,
                               QWidget)


DEFAULT_TYPES = ['int', 'str', 'PySide6.QtCore.QPoint', 'PySide6.QtCore.QRect',
                 'PySide6.QtCore.QSize', 'PySide6.QtGui.QColor']


FUNCTION_PATTERN = r'^\w+\([\w ,]*\)$'


class ValidatingInputDialog(QDialog):
    """A dialog for text input with a regular expression validation."""
    def __init__(self, label, pattern, parent=None):
        super().__init__(parent)
        layout = QVBoxLayout(self)

        self._form_layout = QFormLayout()
        self._lineedit = QLineEdit()
        self._lineedit.setClearButtonEnabled(True)
        re = QRegularExpression(pattern)
        assert(re.isValid())
        self._validator = QRegularExpressionValidator(re, self)
        self._lineedit.setValidator(self._validator)
        self._form_layout.addRow(label, self._lineedit)
        layout.addLayout(self._form_layout)

        bb = QDialogButtonBox(QDialogButtonBox.Ok | QDialogButtonBox.Cancel)
        layout.addWidget(bb)
        bb.rejected.connect(self.reject)
        bb.accepted.connect(self.accept)

    @Property(str)
    def text(self):
        return self._lineedit.text()

    @text.setter
    def text(self, t):
        self._lineedit.setText(t)

    @Property(str)
    def placeholder_text(self):
        return self._lineedit.placeholderText()

    @placeholder_text.setter
    def placeholder_text(self, t):
        self._lineedit.setPlaceholderText(t)

    @Property(int)
    def cursor_position(self):
        return self._lineedit.cursorPosition()

    @cursor_position.setter
    def cursor_position(self, p):
        self._lineedit.setCursorPosition(p)

    def is_valid(self):
        return self.text

    def accept(self):
        if self.is_valid():
            super(ValidatingInputDialog, self).accept()


class FunctionSignatureDialog(ValidatingInputDialog):
    """A dialog for input of function signatures."""
    def __init__(self, name, parent=None):
        super().__init__(name, FUNCTION_PATTERN, parent)
        self.text = '()'
        self.cursor_position = 0


class PropertyDialog(ValidatingInputDialog):
    """A dialog for input of a property name and type."""
    def __init__(self, parent=None):
        super().__init__('&Name:', r'^\w+$', parent)
        self.setWindowTitle('Add a Property')
        self._type_combo = QComboBox()
        self._type_combo.addItems(DEFAULT_TYPES)
        self._form_layout.insertRow(0, '&Type:', self._type_combo)

    def property_type(self):
        return self._type_combo.currentText()


class ListChooser(QGroupBox):
    """A widget for editing a list of strings with a customization point
       for creating the strings."""
    def __init__(self, title, parent=None):
        super().__init__(title, parent)
        main_layout = QHBoxLayout(self)
        self._list = QListWidget(self)
        self._list.currentItemChanged.connect(self._current_item_changed)
        main_layout.addWidget(self._list)

        vbox_layout = QVBoxLayout()
        main_layout.addLayout(vbox_layout)
        self._addButton = QPushButton("Add...")
        vbox_layout.addWidget(self._addButton)
        self._addButton.clicked.connect(self._add)
        self._removeButton = QPushButton("Remove")
        self._removeButton.setEnabled(False)
        self._removeButton.clicked.connect(self._remove_current)
        vbox_layout.addWidget(self._removeButton)
        vbox_layout.addStretch()

    @Property(list)
    def items(self):
        result = []
        for i in range(self._list.count()):
            result.append(self._list.item(i).text())
        return result

    @items.setter
    def items(self, item_list):
        self._list.clear()
        for i in item_list:
            self._list.append(i)

    @Slot(QListWidgetItem, QListWidgetItem)
    def _current_item_changed(self, current, previous):
        self._removeButton.setEnabled(current is not None)

    @Slot()
    def _add(self):
        new_item = self._create_new_item()
        if new_item:
            self._list.addItem(new_item)

    def _create_new_item(self):
        """Overwrite to return a new item."""
        return 'new_item'

    @Slot()
    def _remove_current(self):
        row = self._list.row(self._list.currentItem())
        if row >= 0:
            self._list.takeItem(row)


class SignalChooser(ListChooser):
    """A widget for editing a list of signal function signatures."""
    def __init__(self, parent=None):
        super().__init__('Signals', parent)

    def _create_new_item(self):
        dialog = FunctionSignatureDialog('&Signal signature:', self)
        dialog.setWindowTitle('Enter Signal')
        if dialog.exec() != QDialog.Accepted:
            return ''
        return dialog.text


class PropertyChooser(ListChooser):
    """A widget for editing a list of properties as a string of 'type name'."""
    def __init__(self, parent=None):
        super().__init__('Properties', parent)

    def _create_new_item(self):
        dialog = PropertyDialog(self)
        if dialog.exec() != QDialog.Accepted:
            return ''
        name = dialog.text
        property_type = dialog.property_type()
        return f'{property_type} {name}'