"""省钱记录表。

是 profile「累计帮你省了」和「省钱战绩」的唯一数据源:每完成一次比价/下单,
省了多少记一行。本期比价还没接后端,数据由 demo seeder 幂等灌入(source='demo'),
聚合接口照常做真实 SUM/分组;等比价真接入后,改成上报写入、停掉 seeder 即可。
"""
from __future__ import annotations

from datetime import datetime

from sqlalchemy import JSON, DateTime, ForeignKey, Integer, String, UniqueConstraint, func
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column

from app.db.base import Base


class SavingsRecord(Base):
    __tablename__ = "savings_record"
    __table_args__ = (
        # 真实上报(source='compare')按 (user, client_event_id) 幂等;
        # demo 行 client_event_id 为 NULL,不参与唯一性冲突(SQLite/PG 均允许多 NULL)
        UniqueConstraint("user_id", "client_event_id", name="uq_savings_user_event"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    user_id: Mapped[int] = mapped_column(
        Integer, ForeignKey("user.id"), index=True, nullable=False
    )
    # 订单金额 / 省下金额,单位:分
    order_amount_cents: Mapped[int] = mapped_column(Integer, nullable=False)
    saved_amount_cents: Mapped[int] = mapped_column(Integer, nullable=False)
    platform: Mapped[str | None] = mapped_column(String(32), nullable=True)
    title: Mapped[str | None] = mapped_column(String(128), nullable=True)
    # 店铺名(订单明细卡标题,如「窑鸡王（王府井店）」)
    shop_name: Mapped[str | None] = mapped_column(String(128), nullable=True)
    # 菜品名列表:PG 用 JSONB(可建 GIN 索引),SQLite 用 JSON(TEXT)。前 2 道直接展示,其余收进「还有 N 道菜」。
    dishes: Mapped[list[str]] = mapped_column(
        JSON().with_variant(JSONB(), "postgresql"), nullable=False, default=list
    )
    # 来源:demo(演示) / compare(真实比价上报)
    source: Mapped[str] = mapped_column(String(16), nullable=False, default="compare")

    # ===== 真实比价上报(source='compare')新增字段;demo 行这些均为 NULL =====
    # 源平台原价(用户原本要付的钱,分);省额 saved_amount_cents = original − order_amount(实付)
    original_price_cents: Mapped[int | None] = mapped_column(Integer, nullable=True)
    # 我们当时给出的比价价(分),审计/备用展示
    compared_price_cents: Mapped[int | None] = mapped_column(Integer, nullable=True)
    # 支付渠道:wechat / alipay
    pay_channel: Mapped[str | None] = mapped_column(String(16), nullable=True)
    # 实际下单平台包名
    platform_package: Mapped[str | None] = mapped_column(String(128), nullable=True)
    # 源平台展示名(如「美团」),用于「原价 ¥36.8（美团）」展示
    source_platform_name: Mapped[str | None] = mapped_column(String(32), nullable=True)
    # 源平台重进链接(预留:后续「重新进店/重复下单」用,本期只存不展示)
    source_deeplink: Mapped[str | None] = mapped_column(String(512), nullable=True)
    # 客户端幂等键(UUID);demo 行为 NULL
    client_event_id: Mapped[str | None] = mapped_column(String(64), nullable=True)
    device_id: Mapped[str | None] = mapped_column(String(128), nullable=True)

    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), index=True, nullable=False
    )

    def __repr__(self) -> str:  # pragma: no cover
        return f"<SavingsRecord id={self.id} user_id={self.user_id} saved={self.saved_amount_cents}>"