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


class FollowedTag(models.Model):
    """A tag one user subscribes to; feeds are filled by the sync command."""

    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="followed_tags",
    )
    tag = models.CharField(max_length=200)
    cover_data = models.JSONField(null=True, blank=True)
    last_synced_at = models.DateTimeField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ["tag"]
        constraints = [
            models.UniqueConstraint(
                fields=["user", "tag"], name="uniq_followed_tag_per_user"
            ),
        ]

    def __str__(self):
        return f"{self.user} follows tag:{self.tag}"


class FollowedPool(models.Model):
    """A pool one user subscribes to; feeds are filled by the sync command."""

    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="followed_pools",
    )
    pool_id = models.IntegerField()
    name = models.CharField(max_length=200, blank=True, default="")
    post_count = models.IntegerField(default=0)
    cover_data = models.JSONField(null=True, blank=True)
    last_synced_at = models.DateTimeField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ["pool_id"]
        constraints = [
            models.UniqueConstraint(
                fields=["user", "pool_id"], name="uniq_followed_pool_per_user"
            ),
        ]

    def __str__(self):
        return f"{self.user} follows pool:{self.pool_id}"


class FollowedPost(models.Model):
    """One post seen in a followed feed (stored once per follow source)."""

    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="followed_posts",
    )
    tag = models.ForeignKey(
        FollowedTag,
        null=True,
        blank=True,
        on_delete=models.CASCADE,
        related_name="posts",
    )
    pool = models.ForeignKey(
        FollowedPool,
        null=True,
        blank=True,
        on_delete=models.CASCADE,
        related_name="posts",
    )
    post_id = models.IntegerField(db_index=True)
    data = models.JSONField(default=dict)
    seen = models.BooleanField(default=False, db_index=True)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ["-post_id"]
        indexes = [models.Index(fields=["user", "post_id"])]
        constraints = [
            models.UniqueConstraint(
                fields=["tag", "post_id"], name="uniq_followed_tag_post"
            ),
            models.UniqueConstraint(
                fields=["pool", "post_id"], name="uniq_followed_pool_post"
            ),
        ]

    def __str__(self):
        return f"#{self.post_id} for {self.user}"


class FollowCloud(models.Model):
    """Cached blacklisted-tag cloud for the Followed page, built in a thread."""

    user = models.OneToOneField(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="follow_cloud",
    )
    data = models.JSONField(null=True, blank=True)
    computed_at = models.DateTimeField(null=True, blank=True)
    building = models.BooleanField(default=False)
    building_since = models.DateTimeField(null=True, blank=True)

    def __str__(self):
        return f"Follow cloud for {self.user}"