from PyQt5 import QtCore
from typing import NamedTuple, Optional

from model.task import ValidTaskForm

class TaskFormEdition:
    def __init__(self, name, name_signal, duration, duration_signal, tag, tag_signal):
        self._name = name
        self._duration = duration
        self._tag = tag
        self._signal = ValidTaskFormSignal()
        name_signal.connect(lambda name: self.on_name_signal(name))
        duration_signal.connect(lambda duration: self.on_duration_signal(duration))
        tag_signal.connect(lambda tag: self.on_tag_signal(tag))

    def get(self) -> Optional[ValidTaskForm]:
        name = self._name.strip()
        duration = self._duration.strip()
        tag = self._tag.strip()

        if name and (duration == '' or duration.isdigit()):
            return ValidTaskForm(
                name = name,
                duration = 0 if duration == '' else int(duration),
                tag = tag)
        else:
            return None

    def on_name_signal(self, name: str):
        self._name = name
        self.emit()

    def on_duration_signal(self, duration: str):
        self._duration = duration
        self.emit()

    def on_tag_signal(self, tag: str):
        self._tag = tag
        self.emit()

    def emit(self):
        validForm = self.get()
        if validForm:
            self._signal.emit(validForm)

    def signal(self):
        return self._signal

class ValidTaskFormSignal(QtCore.QObject):
    _signal = QtCore.pyqtSignal(ValidTaskForm, name = 'validTaskForm')

    def __init__(self):
        QtCore.QObject.__init__(self)

    def emit(self, form: Optional[ValidTaskForm]):
        self._signal.emit(form)

    def connect(self, f):
        self._signal.connect(f)