"""Pydantic DTO —— 这就是 OpenAPI 契约（前端据此生成类型化客户端）。

契约先于业务锁定：字段一旦定下，前端可并行开发，后端实现改动不影响前端。
"""
from __future__ import annotations

from datetime import datetime

from pydantic import BaseModel, Field


# ---------- Candle ----------
class CandleOut(BaseModel):
    ts: datetime
    open: float
    high: float
    low: float
    close: float
    volume: float

    model_config = {"from_attributes": True}


# ---------- Backtest ----------
class BacktestRequest(BaseModel):
    symbol: str = "DEMO"
    timeframe: str = "1d"
    strategy: str = "macd_cross"        # macd_cross | ma_cross | single_ma
    params: dict[str, float] = Field(default_factory=dict)  # 各策略参数
    initial_cash: float = 1000000.0
    fast_mode: bool = False  # True => 关闭 T+1/费用，交互试探
    start: datetime | None = None
    end: datetime | None = None


class SignalOut(BaseModel):
    ts: datetime
    side: str   # "buy" | "sell"
    price: float
    qty: float


class EquityPoint(BaseModel):
    ts: datetime
    value: float


class IndicatorOut(BaseModel):
    strategy: str
    data: dict[str, list[float | None]] = {}  # 列名 -> 序列（MACD: macd/signal/hist；均线: fast/slow 或 ma）


class MetricsOut(BaseModel):
    total_return: float
    max_drawdown: float
    sharpe: float
    volatility: float
    num_trades: int = 0
    win_rate: float = 0.0


class BacktestResponse(BaseModel):
    symbol: str
    timeframe: str
    strategy: str
    candles: list[CandleOut]
    indicators: IndicatorOut
    signals: list[SignalOut]
    equity: list[EquityPoint]
    metrics: MetricsOut
    final_cash: float
    final_position: float
    initial_cash: float


class SyncRequest(BaseModel):
    symbol: str
    start: str | None = None       # YYYYMMDD
    end: str | None = None
    source: str = "auto"           # auto | tushare | akshare
    force: bool = False            # True => 忽略缓存重新拉取


class SyncResponse(BaseModel):
    symbol: str
    bars: int
    source: str