from django.db import models

from core.enums import SchoolLevel, SchoolNature, SchoolType
from core.models.base import TimeStampedModel


class District(TimeStampedModel):
    city = models.CharField(
        max_length=50,
        verbose_name="所属城市",
        help_text="支持多城市扩展，如「上海」「北京」",
    )
    name = models.CharField(
        max_length=50,
        verbose_name="行政区名称",
        help_text="如「静安区」",
    )
    short_name = models.CharField(
        max_length=20,
        blank=True,
        default="",
        verbose_name="简称",
        help_text="如「静安」",
    )
    sort_order = models.IntegerField(
        default=0,
        verbose_name="排序",
        help_text="列表展示排序",
    )
    is_active = models.BooleanField(
        default=True,
        verbose_name="是否启用",
        help_text="False=已停用，不在筛选项中展示",
    )

    class Meta:
        db_table = "districts"
        verbose_name = "城区"
        verbose_name_plural = "城区"
        constraints = [
            models.UniqueConstraint(
                fields=["city", "name"],
                condition=models.Q(is_active=True),
                name="uq_districts_city_name",
            ),
        ]
        ordering = ["city", "sort_order", "name"]

    def __str__(self) -> str:
        return f"{self.city} / {self.name}"


class BusinessArea(TimeStampedModel):
    district = models.ForeignKey(
        "region.District",
        on_delete=models.PROTECT,
        related_name="business_areas",
        verbose_name="所属城区",
    )
    name = models.CharField(
        max_length=100,
        verbose_name="商圈名称",
    )
    sort_order = models.IntegerField(
        default=0,
        verbose_name="排序",
    )
    latitude = models.DecimalField(
        max_digits=10,
        decimal_places=7,
        null=True,
        blank=True,
        verbose_name="商圈中心纬度",
    )
    longitude = models.DecimalField(
        max_digits=10,
        decimal_places=7,
        null=True,
        blank=True,
        verbose_name="商圈中心经度",
    )
    is_active = models.BooleanField(
        default=True,
        verbose_name="是否启用",
        help_text="False=已停用，不在筛选项中展示",
    )

    class Meta:
        db_table = "business_areas"
        verbose_name = "商圈"
        verbose_name_plural = "商圈"
        constraints = [
            models.UniqueConstraint(
                fields=["district", "name"],
                name="uq_business_areas_name",
            ),
        ]
        indexes = [
            models.Index(
                fields=["district"],
                name="idx_business_areas_district",
                condition=models.Q(is_active=True),
            ),
        ]
        ordering = ["district_id", "sort_order", "name"]

    def __str__(self) -> str:
        return self.name


class MetroLine(TimeStampedModel):
    city = models.CharField(
        max_length=50,
        verbose_name="所属城市",
    )
    name = models.CharField(
        max_length=50,
        verbose_name="线路名称",
        help_text="如「1号线」",
    )
    color = models.CharField(
        max_length=7,
        blank=True,
        default="",
        verbose_name="线路颜色",
        help_text="HEX 色值，如 #E3002B",
    )
    sort_order = models.IntegerField(
        default=0,
        verbose_name="排序",
    )
    is_active = models.BooleanField(
        default=True,
        verbose_name="是否启用",
        help_text="False=已停用，不在筛选项中展示",
    )

    class Meta:
        db_table = "metro_lines"
        verbose_name = "地铁线路"
        verbose_name_plural = "地铁线路"
        ordering = ["city", "sort_order", "name"]

    def __str__(self) -> str:
        return f"{self.city} {self.name}"


class MetroStation(TimeStampedModel):
    metro_line = models.ForeignKey(
        "region.MetroLine",
        on_delete=models.CASCADE,
        related_name="stations",
        verbose_name="所属线路",
    )
    name = models.CharField(
        max_length=50,
        verbose_name="站名",
    )
    latitude = models.DecimalField(
        max_digits=10,
        decimal_places=7,
        null=True,
        blank=True,
        verbose_name="站点纬度",
    )
    longitude = models.DecimalField(
        max_digits=10,
        decimal_places=7,
        null=True,
        blank=True,
        verbose_name="站点经度",
    )
    sort_order = models.IntegerField(
        default=0,
        verbose_name="沿线排序",
    )
    is_active = models.BooleanField(
        default=True,
        verbose_name="是否启用",
        help_text="False=已停用，不在筛选项中展示",
    )

    class Meta:
        db_table = "metro_stations"
        verbose_name = "地铁站点"
        verbose_name_plural = "地铁站点"
        indexes = [
            models.Index(
                fields=["metro_line"],
                name="idx_metro_stations_line",
                condition=models.Q(is_active=True),
            ),
        ]
        ordering = ["metro_line_id", "sort_order"]

    def __str__(self) -> str:
        return self.name


class School(TimeStampedModel):
    district = models.ForeignKey(
        "region.District",
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="schools",
        verbose_name="所属城区",
    )
    name = models.CharField(
        max_length=100,
        verbose_name="学校名称",
    )
    type = models.CharField(
        max_length=20,
        blank=True,
        default="",
        choices=SchoolType.choices,
        verbose_name="学校类型",
        help_text="primary=小学 / middle=初中 / high=高中 / k9=九年一贯制 / k12=十二年一贯制",
    )
    nature = models.CharField(
        max_length=20,
        blank=True,
        default="",
        choices=SchoolNature.choices,
        verbose_name="学校性质",
        help_text="public=公立 / private=私立 / international=国际学校",
    )
    level = models.CharField(
        max_length=20,
        blank=True,
        default="",
        choices=SchoolLevel.choices,
        verbose_name="学校等级",
        help_text="normal=普通 / key=重点 / top=名校",
    )
    is_active = models.BooleanField(
        default=True,
        verbose_name="是否启用",
        help_text="False=已停用，不在筛选项中展示",
    )

    class Meta:
        db_table = "schools"
        verbose_name = "学校"
        verbose_name_plural = "学校"
        indexes = [
            models.Index(
                fields=["district"],
                name="idx_schools_district",
                condition=models.Q(is_active=True),
            ),
        ]
        ordering = ["name"]

    def __str__(self) -> str:
        return self.name