"""按 fin_product 为指定客户生成 fin_holdings 持仓数据（本地开发/演示用）。

用法：
    python scripts/seed_holdings_for_customer.py --customer-id 18
    python scripts/seed_holdings_for_customer.py --customer-id 18 --count 5 --force

规则：
- 只挑选 fin_product 中 status=在售 的产品，按 id 升序取前 count 只；
- 每笔持仓的买入净值 = 当前净值 × (1 - 浮动)，浮动由固定 seed 生成，保证可复现；
- shares = cost_amount / 买入净值（4 位小数），current_value = shares × 当前净值；
- profit_loss / profit_ratio 由上述字段推导；
- 客户已有持仓时默认拒绝，需 --force 才会追加。
"""
from __future__ import annotations

import argparse
import asyncio
import random
import sys
from decimal import Decimal, ROUND_HALF_UP
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))

from sqlalchemy import select

from config.database.mysql import get_session_factory
from model.fin_holdings import FinHoldings
from model.fin_product import FinProduct
from model.sys_user import SysUser

_MONEY = Decimal("0.01")
_SHARES = Decimal("0.0001")
_RATIO = Decimal("0.0001")


def _money(value: Decimal) -> Decimal:
    return value.quantize(_MONEY, rounding=ROUND_HALF_UP)


async def seed(customer_id: int, *, count: int, force: bool) -> list[dict]:
    session_factory = get_session_factory()
    async with session_factory() as db:
        user = await db.get(SysUser, customer_id)
        if user is None or user.user_type != "CUSTOMER":
            raise SystemExit(f"customer_id={customer_id} 不是客户用户或不存在")

        existing = (
            await db.execute(
                select(FinHoldings).where(FinHoldings.customer_id == customer_id)
            )
        ).scalars().all()
        if existing and not force:
            raise SystemExit(
                f"客户 {customer_id} 已有 {len(existing)} 条持仓，如需追加请加 --force"
            )

        products = (
            await db.execute(
                select(FinProduct)
                .where(FinProduct.status == "在售")
                .order_by(FinProduct.id)
                .limit(count)
            )
        ).scalars().all()
        if not products:
            raise SystemExit("fin_product 中没有在售产品")

        rng = random.Random(f"holdings-{customer_id}")
        created: list[dict] = []
        for product in products:
            nav = product.nav or Decimal("1.000000")
            cost_amount = _money(Decimal(rng.randint(5_000, 50_000)))
            # 买入净值在当前净值的 88%~97% 之间浮动，形成有涨有跌的持仓
            buy_nav = _money(nav * Decimal(str(round(rng.uniform(0.88, 0.97), 6))))
            if buy_nav <= 0:
                buy_nav = Decimal("1.0000")
            shares = (cost_amount / buy_nav).quantize(_SHARES, rounding=ROUND_HALF_UP)
            current_value = _money(shares * nav)
            profit_loss = _money(current_value - cost_amount)
            profit_ratio = (profit_loss / cost_amount).quantize(_RATIO, rounding=ROUND_HALF_UP)

            db.add(
                FinHoldings(
                    customer_id=customer_id,
                    product_id=product.id,
                    shares=shares,
                    cost_amount=cost_amount,
                    current_value=current_value,
                    profit_loss=profit_loss,
                    profit_ratio=profit_ratio,
                    status="持有中",
                )
            )
            created.append(
                {
                    "product_id": product.id,
                    "product_name": product.product_name,
                    "buy_nav": str(buy_nav),
                    "nav": str(nav),
                    "shares": str(shares),
                    "cost_amount": str(cost_amount),
                    "current_value": str(current_value),
                    "profit_loss": str(profit_loss),
                    "profit_ratio": str(profit_ratio),
                }
            )

        await db.commit()
        return created


def main() -> None:
    parser = argparse.ArgumentParser(description="按 fin_product 生成客户持仓数据")
    parser.add_argument("--customer-id", type=int, required=True)
    parser.add_argument("--count", type=int, default=8, help="生成持仓条数（默认 8）")
    parser.add_argument(
        "--force", action="store_true", help="客户已有持仓时仍允许追加"
    )
    args = parser.parse_args()

    created = asyncio.run(seed(args.customer_id, count=args.count, force=args.force))
    total_cost = sum(Decimal(item["cost_amount"]) for item in created)
    total_value = sum(Decimal(item["current_value"]) for item in created)
    print(f"客户 {args.customer_id} 新增持仓 {len(created)} 条：")
    for item in created:
        print(
            f"  [{item['product_id']}] {item['product_name'][:24]}… "
            f"买入净值={item['buy_nav']} 当前净值={item['nav']} "
            f"份额={item['shares']} 成本={item['cost_amount']} "
            f"市值={item['current_value']} 盈亏={item['profit_loss']} "
            f"({item['profit_ratio']})"
        )
    print(f"合计：成本 {total_cost} 元，市值 {total_value} 元，"
          f"盈亏 {total_value - total_cost} 元")


if __name__ == "__main__":
    main()