"""
Sync models for KeepItGoing.

Tracks sync state for offline clients.
"""

import uuid
from django.conf import settings
from django.db import models


class SyncLog(models.Model):
    """
    Tracks sync operations for each user/device.
    """
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name='sync_logs'
    )
    device_id = models.CharField(max_length=255)
    last_sync_at = models.DateTimeField()
    sync_token = models.CharField(max_length=255, unique=True)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        db_table = 'sync_logs'
        unique_together = ['user', 'device_id']

    def __str__(self):
        return f"{self.user.email} - {self.device_id}"


class SyncConflict(models.Model):
    """
    Records sync conflicts for manual resolution.
    """
    CONFLICT_STATUS = [
        ('pending', 'Pending'),
        ('resolved_local', 'Resolved (Local)'),
        ('resolved_server', 'Resolved (Server)'),
        ('resolved_merged', 'Resolved (Merged)'),
    ]

    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name='sync_conflicts'
    )
    entity_type = models.CharField(max_length=50)  # task, group, tag, etc.
    entity_id = models.UUIDField()
    local_data = models.JSONField()
    server_data = models.JSONField()
    status = models.CharField(max_length=20, choices=CONFLICT_STATUS, default='pending')
    resolved_at = models.DateTimeField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        db_table = 'sync_conflicts'
        ordering = ['-created_at']

    def __str__(self):
        return f"{self.entity_type} conflict for {self.user.email}"