from __future__ import annotations

from enum import Enum
from typing import ClassVar

from django.db import models


class OrderStatus(Enum):
    PENDING = "pending"
    SUCCESS = "success"
    FAILED = "failed"

    @classmethod
    def choices(cls):
        return [(tag.name, tag.value) for tag in cls]


class Product(models.Model):
    """
    商品模型
    """

    id = models.AutoField(verbose_name="商品ID", primary_key=True)
    name = models.CharField(verbose_name="商品名称", max_length=255, db_index=True)
    description = models.TextField(verbose_name="商品描述", blank=True)
    price = models.DecimalField(verbose_name="商品价格", max_digits=10, decimal_places=2)
    stock = models.PositiveIntegerField(verbose_name="商品库存", default=0)
    keywords = models.CharField(verbose_name="商品关键词", max_length=255, blank=True)
    updated_at = models.DateTimeField(verbose_name="更新时间", auto_now=True)

    class Meta:
        verbose_name = "商品"
        indexes: ClassVar[list[models.Index]] = [
            models.Index(fields=["name"], name="idx_product_name"),
            models.Index(fields=["keywords"], name="idx_product_keywords"),
        ]


class Order(models.Model):
    """
    订单模型
    """

    created_at = models.DateTimeField(verbose_name="创建时间", auto_now_add=True)
    status = models.CharField(verbose_name="订单状态", max_length=32, default=OrderStatus.PENDING.value)


class OrderItem(models.Model):
    """
    订单项模型
    """

    order = models.ForeignKey(Order, related_name="items", on_delete=models.CASCADE)
    product = models.ForeignKey(Product, on_delete=models.PROTECT)
    quantity = models.PositiveIntegerField(verbose_name="数量")
    price = models.DecimalField(verbose_name="价格", max_digits=10, decimal_places=2)
    status = models.CharField(verbose_name="订单项状态", max_length=32, default=OrderStatus.SUCCESS.value)
    fail_reason = models.CharField(verbose_name="失败原因", max_length=255, blank=True)