from django.db import models
from utils.models import CampRelatedModel
from django.core.exceptions import ValidationError

import reversion


class InfoCategory(CampRelatedModel):
    class Meta:
        ordering = ['weight', 'headline']
        verbose_name_plural = "Info Categories"

    headline = models.CharField(
        max_length=100,
        help_text="The headline of this info category"
    )

    anchor = models.SlugField(
        help_text="The HTML anchor to use for this info category."
    )

    weight = models.PositiveIntegerField(
        help_text='Determines sorting/ordering. Heavier categories sink to the bottom. Categories with the same weight are ordered alphabetically. Defaults to 100.',
        default=100,
    )

    team = models.ForeignKey(
        'teams.Team',
        help_text='The team responsible for this info category.',
        on_delete=models.PROTECT,
        related_name='info_categories'
    )

    def clean(self):
        if InfoItem.objects.filter(category__team__camp=self.camp, anchor=self.anchor).exists():
            # this anchor is already in use on an item, so it cannot be used (must be unique on the page)
            raise ValidationError(
                {'anchor': 'Anchor is already in use on an info item for this camp'}
            )

    @property
    def camp(self):
        return self.team.camp

    camp_filter = 'team__camp'

    def __str__(self):
        return '%s (%s)' % (self.headline, self.camp)


# We want to have info items under version control
@reversion.register()
class InfoItem(CampRelatedModel):
    class Meta:
        ordering = ['weight', 'headline']
        unique_together = (('anchor', 'category'), ('headline', 'category'))

    category = models.ForeignKey(
        'info.InfoCategory',
        related_name='infoitems',
        on_delete=models.PROTECT
    )

    headline = models.CharField(
        max_length=100,
        help_text="Headline of this info item."
    )

    anchor = models.SlugField(
        help_text="The HTML anchor to use for this info item."
    )

    body = models.TextField(
        help_text='Body of this info item. Markdown is supported.'
    )

    weight = models.PositiveIntegerField(
        help_text='Determines sorting/ordering. Heavier items sink to the bottom. Items with the same weight are ordered alphabetically. Defaults to 100.',
        default=100,
    )

    @property
    def camp(self):
        return self.category.camp

    camp_filter = 'category__team__camp'

    def clean(self):
        if hasattr(self, 'category') and InfoCategory.objects.filter(team__camp=self.category.team.camp, anchor=self.anchor).exists():
            # this anchor is already in use on a category, so it cannot be used here (they must be unique on the entire page)
            raise ValidationError({'anchor': 'Anchor is already in use on an info category for this camp'})

    def __str__(self):
        return '%s (%s)' % (self.headline, self.category)