from django.db import models


class FamilyLink(models.Model):
    """
    اتصال حساب والد به یک فرزند. طبق سند معماری، این اپ فقط به accounts.User
    ارجاع سبک (parent_user_id / child_user_id) می‌ده، نه FK واقعی.
    """
    STATUS_CHOICES = [('pending', 'در انتظار'), ('accepted', 'پذیرفته‌شده')]

    parent_user_id = models.IntegerField(db_index=True)  # ارجاع سبک به accounts.User
    child_user_id = models.IntegerField(null=True, blank=True, db_index=True)  # ارجاع سبک به accounts.User
    child_phone = models.CharField(max_length=15, blank=True)
    invite_code = models.CharField(max_length=10, unique=True)
    status = models.CharField(max_length=10, choices=STATUS_CHOICES, default='pending')
    invited_at = models.DateTimeField(auto_now_add=True)
    accepted_at = models.DateTimeField(null=True, blank=True)

    class Meta:
        ordering = ['-invited_at']
        constraints = [
            # حداکثر یک دعوت pending هم‌زمان برای هر (parent_user_id, child_phone).
            models.UniqueConstraint(
                fields=['parent_user_id', 'child_phone'],
                condition=models.Q(status='pending'),
                name='uniq_pending_family_invite_per_parent_child',
            ),
        ]

    def __str__(self):
        return f"famlink-{self.pk}-parent{self.parent_user_id}-child{self.child_user_id or '?'}"


class ParentalSettings(models.Model):
    family_link = models.OneToOneField(FamilyLink, on_delete=models.CASCADE, related_name='settings')
    daily_limit_minutes = models.PositiveIntegerField(default=60)
    quiet_hours_start = models.TimeField(null=True, blank=True)
    quiet_hours_end = models.TimeField(null=True, blank=True)

    def __str__(self):
        return f"settings-famlink{self.family_link_id}"


class WeeklyReportLog(models.Model):
    family_link = models.ForeignKey(FamilyLink, on_delete=models.CASCADE, related_name='weekly_reports')
    week_start = models.DateField()
    sent_at = models.DateTimeField(null=True, blank=True)
    opened_at = models.DateTimeField(null=True, blank=True)

    class Meta:
        ordering = ['-week_start']
        unique_together = [('family_link', 'week_start')]

    def __str__(self):
        return f"weekly-famlink{self.family_link_id}-{self.week_start}"