from PyQt5 import QtWidgets
from typing import Optional

import db.tasks
from model.task import Task, ValidTaskForm

import gui.icons
import gui.tasks.form.state
import gui.tasks.duration

def widget(
        parent: QtWidgets.QWidget,
        action_title: str,
        task: Task,
        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 = task.name if task is not None else ''
    name_input = add_input(grid, grid_layout, 0, 'Name', init_name)

    init_duration = gui.tasks.duration.format(task.duration) if task is not None else ''
    duration_input = add_input(grid, grid_layout, 1, 'Duration', init_duration)

    init_tag = task.tag if task is not None else ''
    tag_input = add_input(grid, grid_layout, 2, 'Tag', init_tag)

    task_form_edition = gui.tasks.form.state.TaskFormEdition(
            init_name,
            name_input.textChanged,
            init_duration,
            duration_input.textChanged,
            init_tag,
            tag_input.textChanged)

    layout.addWidget(buttons(
            parent = widget,
            action_title = action_title,
            task_form_signal = task_form_edition.signal(),
            on_validate = lambda: validate(task_form_edition.get(), on_validated),
            on_cancel = on_cancel))

    return widget

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

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

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

    return line_edit

def buttons(parent, action_title, task_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(gui.icons.dialog_apply(validate.style()))
    validate.clicked.connect(on_validate);
    layout.addWidget(validate)

    def on_task_form_signal(form: Optional[ValidTaskForm]):
        if form:
            validate.setEnabled(True)
        else:
            validate.setDisabled(True)

    task_form_signal.connect(on_task_form_signal)

    cancel = QtWidgets.QPushButton('cancel', widget)
    cancel.setIcon(gui.icons.dialog_cancel(cancel.style()))
    cancel.clicked.connect(on_cancel)
    layout.addWidget(cancel)

    return widget

def validate(form: Optional[ValidTaskForm], on_validated):
    if form:
        on_validated(form)