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)

    init_name = task.name if task is not None else ''
    (name_labelled_input, name_input) = labelled_input(widget, 'Name', init_name)
    layout.addWidget(name_labelled_input)

    init_duration = gui.tasks.duration.format(task.duration) if task is not None else ''
    (duration_labelled_input, duration_input) = labelled_input(widget, 'Duration', init_duration)
    layout.addWidget(duration_labelled_input)

    init_tag = task.tag if task is not None else ''
    (tag_labelled_input, tag_input) = labelled_input(widget, 'Tag', init_tag)
    layout.addWidget(tag_labelled_input)

    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 labelled_input(parent, label: str, default_value: str):
    widget = QtWidgets.QWidget(parent)

    layout = QtWidgets.QHBoxLayout(widget)
    widget.setLayout(layout)

    label = QtWidgets.QLabel(label, widget)
    layout.addWidget(label)

    line_edit = QtWidgets.QLineEdit(widget)
    if default_value != None:
        line_edit.setText(default_value)
    layout.addWidget(line_edit)

    return (widget, 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)