from django.db import models


class Homework(models.Model):
    title = models.CharField(max_length=200)
    description = models.TextField(blank=True)
    club = models.ForeignKey('clubs.Club', on_delete=models.CASCADE, related_name='homework_templates', null=True, blank=True)
    due_date = models.DateField(null=True, blank=True)
    is_active = models.BooleanField(default=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['due_date']),
            models.Index(fields=['club']),
        ]

    def __str__(self):
        return self.title


class HomeworkExerciseItem(models.Model):
    homework = models.ForeignKey(Homework, on_delete=models.CASCADE, related_name='exercise_items')
    exercise = models.ForeignKey('exercises.Exercise', on_delete=models.CASCADE, related_name='homework_items')
    reps = models.PositiveIntegerField(null=True, blank=True)
    time_minutes = models.PositiveIntegerField(null=True, blank=True)
    order = models.IntegerField(default=0)

    class Meta:
        ordering = ['homework', 'order']
        unique_together = ['homework', 'exercise']

    def __str__(self):
        return f"{self.homework.title} - {self.exercise.name}"


class HomeworkAssignment(models.Model):
    homework = models.ForeignKey(Homework, on_delete=models.CASCADE, related_name='assignments')
    wrestler = models.ForeignKey('wrestlers.Wrestler', on_delete=models.CASCADE, related_name='homework_assignments')
    club = models.ForeignKey('clubs.Club', on_delete=models.CASCADE, related_name='homework_assignments', null=True, blank=True)
    due_date = models.DateField(null=True, blank=True)
    notes = models.TextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        unique_together = ['homework', 'wrestler']
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['wrestler']),
            models.Index(fields=['due_date']),
        ]

    def __str__(self):
        return f"{self.wrestler} - {self.homework.title}"

    def clean(self):
        from wrestlers.models import Wrestler
        if self.wrestler and self.homework and self.wrestler.club_id != self.homework.club_id:
            from django.core.exceptions import ValidationError
            raise ValidationError('Wrestler must belong to the same club as the homework')

    @property
    def is_completed(self):
        items = self.items.all()
        if not items.exists():
            return False
        return all(item.is_completed for item in items)

    @property
    def completion_date(self):
        if self.is_completed:
            return self.items.filter(is_completed=True).order_by('-completion_date').first().completion_date
        return None


class HomeworkAssignmentItem(models.Model):
    assignment = models.ForeignKey(HomeworkAssignment, on_delete=models.CASCADE, related_name='items')
    exercise = models.ForeignKey('exercises.Exercise', on_delete=models.CASCADE, related_name='assignment_items')
    is_completed = models.BooleanField(default=False)
    completion_date = models.DateField(null=True, blank=True)

    class Meta:
        unique_together = ['assignment', 'exercise']
        indexes = [
            models.Index(fields=['assignment', 'is_completed']),
            models.Index(fields=['completion_date']),
        ]

    def __str__(self):
        status = "✓" if self.is_completed else "✗"
        return f"{self.assignment} - {self.exercise.name} {status}"


class HomeworkStatus(models.Model):
    homework = models.ForeignKey(Homework, on_delete=models.CASCADE, related_name='statuses')
    wrestler = models.ForeignKey('wrestlers.Wrestler', on_delete=models.CASCADE, related_name='homework_statuses')
    is_completed = models.BooleanField(default=False)
    completion_date = models.DateField(null=True, blank=True)
    notes = models.TextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        unique_together = ['homework', 'wrestler']

    def __str__(self):
        status = "✓" if self.is_completed else "✗"
        return f"{self.wrestler} - {self.homework.title} {status}"


# NEUES SYSTEM: Training-basierte Homework
# Jeder Wrestler bekommt individuelle Übungen zugewiesen

class TrainingHomeworkAssignment(models.Model):
    """A homework assignment for a specific wrestler in a specific training"""
    training = models.ForeignKey('trainings.Training', on_delete=models.CASCADE, related_name='homework_assignments', default=1)
    wrestler = models.ForeignKey('wrestlers.Wrestler', on_delete=models.CASCADE, related_name='training_homework_assignments')
    club = models.ForeignKey('clubs.Club', on_delete=models.CASCADE, related_name='training_homework_assignments', null=True, blank=True)
    notes = models.TextField(blank=True)
    is_completed = models.BooleanField(default=False)
    completion_date = models.DateField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        unique_together = ['training', 'wrestler']
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['training']),
            models.Index(fields=['wrestler']),
            models.Index(fields=['is_completed']),
            models.Index(fields=['club']),
        ]

    def __str__(self):
        return f"{self.wrestler} - Training {self.training_id}"


class TrainingHomeworkExerciseItem(models.Model):
    """Individual exercises assigned to a specific wrestler (NOT shared)"""
    assignment = models.ForeignKey(TrainingHomeworkAssignment, on_delete=models.CASCADE, related_name='exercises')
    exercise = models.ForeignKey('exercises.Exercise', on_delete=models.CASCADE, related_name='training_homework_exercises')
    reps = models.PositiveIntegerField(null=True, blank=True)
    time_minutes = models.PositiveIntegerField(null=True, blank=True)
    order = models.IntegerField(default=0)
    is_completed = models.BooleanField(default=False)

    class Meta:
        ordering = ['assignment', 'order']

    def __str__(self):
        return f"{self.assignment} - {self.exercise.name}"


# ALTES SYSTEM (für Rückwärtskompatibilität - wird nicht mehr verwendet)

class TrainingHomework(models.Model):
    """DEPRECATED: Each wrestler now has individual assignments"""
    training = models.ForeignKey('trainings.Training', on_delete=models.CASCADE, related_name='homework_legacy')
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['training']),
        ]

    def __str__(self):
        return f"Homework for Training {self.training_id}"


class TrainingHomeworkExercise(models.Model):
    """DEPRECATED: Exercises are now per-assignment"""
    training_homework = models.ForeignKey(TrainingHomework, on_delete=models.CASCADE, related_name='exercises')
    exercise = models.ForeignKey('exercises.Exercise', on_delete=models.CASCADE, related_name='training_homework_items')
    reps = models.PositiveIntegerField(null=True, blank=True)
    time_minutes = models.PositiveIntegerField(null=True, blank=True)
    order = models.IntegerField(default=0)

    class Meta:
        ordering = ['training_homework', 'order']
        unique_together = ['training_homework', 'exercise']

    def __str__(self):
        return f"{self.training_homework} - {self.exercise.name}"