from django.contrib.auth import get_user_model
from django.db import models

from books.models import Module
from users.models import SchoolClass


class ObjectiveGroup(models.Model):
    class Meta:
        verbose_name = 'Lernzielgruppe'
        verbose_name_plural = 'Lernzielgruppen'

    LANGUAGE_COMMUNICATION = 'language_communication'
    SOCIETY = 'society'

    TITLE_CHOICES = (
        (LANGUAGE_COMMUNICATION, 'Sprache & Kommunikation'),
        (SOCIETY, 'Gesellschaft'),
    )

    title = models.CharField('title', blank=True, null=False, max_length=255, choices=TITLE_CHOICES, default=LANGUAGE_COMMUNICATION)
    module = models.ForeignKey(Module, blank=False, null=False, on_delete=models.CASCADE, related_name='objective_groups')
    # a user can define her own objectives, hence this optional param
    owner = models.ForeignKey(get_user_model(), blank=True, null=True, on_delete=models.CASCADE)

    hidden_for = models.ManyToManyField(SchoolClass, related_name='hidden_objective_groups', blank=True)
    visible_for = models.ManyToManyField(SchoolClass, related_name='visible_objective_groups', blank=True)

    def __str__(self):
        return '{} - {}'.format(self.module, self.title)


class Objective(models.Model):
    class Meta:
        verbose_name = 'Lernziel'
        verbose_name_plural = 'Lernziele'

    text = models.CharField('text', blank=True, null=False, max_length=255)
    group = models.ForeignKey(ObjectiveGroup, blank=False, null=False, on_delete=models.CASCADE,
                              related_name='objectives')
    owner = models.ForeignKey(get_user_model(), blank=True, null=True, on_delete=models.CASCADE)
    hidden_for = models.ManyToManyField(SchoolClass, related_name='hidden_objectives', blank=True)
    visible_for = models.ManyToManyField(SchoolClass, related_name='visible_objectives', blank=True)

    def __str__(self):
        return 'Objective {}-{}'.format(self.id, self.text)


class ObjectiveProgressStatus(models.Model):
    class Meta:
        verbose_name = 'Lernzielstatus'
        verbose_name_plural = 'Lernzielstatus'

    done = models.BooleanField('Lernziel erledigt?', default=False)
    objective = models.ForeignKey(Objective, blank=False, null=False, on_delete=models.CASCADE,
                                  related_name='objective_progress')
    user = models.ForeignKey(get_user_model(), blank=True, null=True, on_delete=models.CASCADE)

    def __str__(self):
        return 'Lernzielstatus {}-{}'.format(self.objective, self.done)