from django.db import models
from django.utils.translation import gettext_lazy as _


class Tournament(models.Model):
    """Stellt ein komplettes Turnier dar."""
    name = models.CharField(_('Turniername'), max_length=200)
    date = models.DateField(_('Datum'))
    description = models.TextField(_('Beschreibung'), blank=True, default='')
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ['-date']

    def __str__(self):
        return f"{self.name} ({self.date})"


class Registration(models.Model):
    """Verknüpfungstabelle zwischen Turnier und Spielern."""
    tournament = models.ForeignKey(
        Tournament,
        on_delete=models.CASCADE,
        related_name='registrations'
    )
    # FIX: App-Label hinzugefügt ('accounts.Player')
    player = models.ForeignKey(
        'accounts.Player',
        on_delete=models.CASCADE
    )

    class Meta:
        unique_together = ('tournament', 'player')


class Round(models.Model):
    """Eine einzelne Runde im Turnier."""
    tournament = models.ForeignKey(
        Tournament,
        on_delete=models.CASCADE,
        related_name='rounds'
    )
    round_number = models.PositiveIntegerField(_('Rundennummer'))

    class Meta:
        unique_together = ('tournament', 'round_number')
        ordering = ['round_number']

    def __str__(self):
        return f"{self.tournament.name} - Runde {self.round_number}"


class Match(models.Model):
    """Einzelnes Spiel (Paarung) innerhalb einer Runde."""

    class ResultStatus(models.TextChoices):
        PENDING = 'pending', _('Ausstehend')
        WHITE_WIN = 'white_win', _('Weiß gewinnt')
        BLACK_WIN = 'black_win', _('Schwarz gewinnt')
        DRAW = 'draw', _('Unentschieden')

    round_detail = models.ForeignKey(
        Round,
        on_delete=models.CASCADE,
        related_name='matches'
    )

    # FIX: App-Label explizit gesetzt ('accounts.Player')
    player_white = models.ForeignKey(
        'accounts.Player',
        on_delete=models.PROTECT,
        related_name='matches_as_white',
        verbose_name=_('Weißer Spieler')
    )
    player_black = models.ForeignKey(
        'accounts.Player',
        on_delete=models.PROTECT,
        related_name='matches_as_black',
        verbose_name=_('Schwarzer Spieler')
    )

    result = models.CharField(
        max_length=10,
        choices=ResultStatus.choices,
        default=ResultStatus.PENDING
    )

    class Meta:
        unique_together = ('round_detail', 'player_white', 'player_black')

    def __str__(self):
        return f"{self.player_white} vs {self.player_black} ({self.round_detail})"