from django.db import models


class City(models.Model):
    id = models.BigAutoField(primary_key=True)
    name = models.CharField(max_length=50)


class Country(models.Model):
    id = models.SmallAutoField(primary_key=True)
    name = models.CharField(max_length=50)


class District(models.Model):
    city = models.ForeignKey(City, models.CASCADE, primary_key=True)
    name = models.CharField(max_length=50)


class Reporter(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=30)
    email = models.EmailField()
    facebook_user_id = models.BigIntegerField(null=True)
    raw_data = models.BinaryField(null=True)
    small_int = models.SmallIntegerField()
    interval = models.DurationField()

    class Meta:
        unique_together = ("first_name", "last_name")


class Article(models.Model):
    headline = models.CharField(max_length=100)
    pub_date = models.DateField()
    body = models.TextField(default="")
    reporter = models.ForeignKey(Reporter, models.CASCADE)
    response_to = models.ForeignKey("self", models.SET_NULL, null=True)
    unmanaged_reporters = models.ManyToManyField(
        Reporter, through="ArticleReporter", related_name="+"
    )

    class Meta:
        ordering = ("headline",)
        indexes = [
            models.Index(fields=["headline", "pub_date"]),
            models.Index(fields=["headline", "response_to", "pub_date", "reporter"]),
        ]


class ArticleReporter(models.Model):
    article = models.ForeignKey(Article, models.CASCADE)
    reporter = models.ForeignKey(Reporter, models.CASCADE)

    class Meta:
        managed = False


class Comment(models.Model):
    ref = models.UUIDField(unique=True)
    article = models.ForeignKey(Article, models.CASCADE, db_index=True)
    email = models.EmailField()
    pub_date = models.DateTimeField()
    body = models.TextField()

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=["article", "email", "pub_date"],
                name="article_email_pub_date_uniq",
            ),
        ]
        indexes = [
            models.Index(fields=["email", "pub_date"], name="email_pub_date_idx"),
        ]


class CheckConstraintModel(models.Model):
    up_votes = models.PositiveIntegerField()
    voting_number = models.PositiveIntegerField(unique=True)

    class Meta:
        required_db_features = {
            "supports_table_check_constraints",
        }
        constraints = [
            models.CheckConstraint(
                name="up_votes_gte_0_check", check=models.Q(up_votes__gte=0)
            ),
        ]


class UniqueConstraintConditionModel(models.Model):
    name = models.CharField(max_length=255)
    color = models.CharField(max_length=32, null=True)

    class Meta:
        required_db_features = {"supports_partial_indexes"}
        constraints = [
            models.UniqueConstraint(
                fields=["name"],
                name="cond_name_without_color_uniq",
                condition=models.Q(color__isnull=True),
            ),
        ]


class DbCommentModel(models.Model):
    name = models.CharField(max_length=15, db_comment="'Name' column comment")

    class Meta:
        db_table_comment = "Custom table comment"
        required_db_features = {"supports_comments"}