from PyQt5 import QtWidgets, QtCore, QtGui
from typing import Optional, Tuple, List, Any

from todo.model.tag import Tag, ValidTagForm
from todo.model import difficulty, priority
import todo.gui.icon
import todo.gui.tags.panel.form.state
import todo.gui.color

def widget(
        parent: QtWidgets.QWidget,
        action_title: str,
        tag: Tag,
        on_validated,
        on_cancel):

    widget = QtWidgets.QWidget(parent)
    layout = QtWidgets.QVBoxLayout(widget)
    widget.setLayout(layout)

    grid = QtWidgets.QWidget(widget)
    layout.addWidget(grid)
    grid_layout = QtWidgets.QGridLayout(grid)
    grid.setLayout(grid_layout)

    init_name = tag.name if tag is not None else ""
    name_input = line_edit(grid, grid_layout, 0, "Name", init_name)

    init_color = tag.color if tag is not None else "#FFFFFF"
    color_input = color_edit(grid, grid_layout, 1, "Color", QtGui.QColor(init_color))

    tag_form_edition = todo.gui.tags.panel.form.state.TagFormEdition(
            init_name,
            name_input.textChanged,
            init_color,
            color_input.textChanged)

    def on_validate():
        form = tag_form_edition.get()
        if form:
            on_validated(form)

    layout.addWidget(buttons(
            parent = widget,
            action_title = action_title,
            tag_form_signal = tag_form_edition.signal(),
            on_validate = on_validate,
            on_cancel = on_cancel))

    return widget

def line_edit(
        parent,
        layout: QtWidgets.QGridLayout,
        n: int,
        label: str,
        default_value: str) -> QtWidgets.QLineEdit:

    label = QtWidgets.QLabel(label, parent)
    layout.addWidget(label, n, 0)

    edit = QtWidgets.QLineEdit(parent)
    if default_value != None:
        edit.setText(default_value)
    layout.addWidget(edit, n, 1)

    return edit

def color_edit(
        parent,
        layout: QtWidgets.QGridLayout,
        n: int,
        label: str,
        init_color: QtGui.QColor) -> QtWidgets.QLineEdit:

    label = QtWidgets.QLabel(label, parent)
    layout.addWidget(label, n, 0)

    edit = ColorInput(init_color, parent)
    layout.addWidget(edit, n, 1)

    return edit

class ColorInput(QtWidgets.QLineEdit):

    def __init__(self, init_color: QtGui.QColor, parent):
        super().__init__(parent)
        self.setReadOnly(True)
        self.installEventFilter(self)
        self._color = init_color
        self.update(init_color)
        self._is_editing = False

    def eventFilter(self, source, event):
        if source is self and event.type() == QtCore.QEvent.FocusIn:
            if not self._is_editing:
                self._is_editing = True
                color = QtWidgets.QColorDialog.getColor(self._color, self)
                if color.isValid():
                    self.update(color)
            else:
                self._is_editing = False
                self.clearFocus()
        return super(ColorInput, self).eventFilter(source, event)

    def update(self, color: QtGui.QColor):
        self._color = color
        self.setText(color.name().upper())
        palette = QtGui.QPalette()
        palette.setColor(QtGui.QPalette.Base, color)
        palette.setColor(QtGui.QPalette.Text, color)
        self.setPalette(palette)

def buttons(parent, action_title, tag_form_signal, on_validate, on_cancel):
    widget = QtWidgets.QWidget(parent)
    layout = QtWidgets.QHBoxLayout(widget)

    validate = QtWidgets.QPushButton(action_title, widget)
    validate.setDisabled(True)
    validate.setIcon(todo.gui.icon.dialog_ok(validate.style()))
    validate.clicked.connect(on_validate);
    layout.addWidget(validate)

    def on_tag_form_signal(form: Optional[ValidTagForm]):
        if form:
            validate.setEnabled(True)
        else:
            validate.setDisabled(True)

    tag_form_signal.connect(on_tag_form_signal)

    cancel = QtWidgets.QPushButton("cancel", widget)
    cancel.setIcon(todo.gui.icon.dialog_cancel(cancel.style()))
    cancel.clicked.connect(on_cancel)
    layout.addWidget(cancel)

    return widget