from __future__ import annotations

from typing import Annotated, Any

from fastapi import APIRouter, Depends

from ..config import get_settings
from ..models.db import get_db
from ..sim.pnl import summarize_fills_pnl
from .auth import require_user

router = APIRouter(prefix="/api/stats", tags=["stats"])


def _current_loss_streak(curve: list[dict[str, Any]]) -> int:
    """从最近已平仓组往前数连续亏损次数。"""
    streak = 0
    for item in reversed(curve):
        if float(item.get("realized_pnl") or 0) < 0:
            streak += 1
        else:
            break
    return streak


def build_stats_summary(db: Any | None = None) -> dict[str, Any]:
    """已平仓组汇总（策略页统计 / 中控 Fleet 共用）。"""
    database = db or get_db()
    s = get_settings()
    mode = "LIVE" if not s.is_sim else "SIM"
    rows = database.fetchall("SELECT * FROM groups WHERE status='closed'")
    n = len(rows)
    wins = sum(1 for r in rows if float(r["realized_pnl"] or 0) > 0)
    total_pnl = sum(float(r["realized_pnl"] or 0) for r in rows)
    pnls = [float(r["realized_pnl"] or 0) for r in rows]
    max_single_loss = min(pnls) if pnls else 0.0
    if max_single_loss > 0:
        max_single_loss = 0.0

    fees_perp = 0.0
    fees_option = 0.0
    total_slip = 0.0
    for r in rows:
        fills = database.fetchall(
            "SELECT * FROM fills WHERE group_id=? ORDER BY id ASC",
            (r["group_id"],),
        )
        summary = summarize_fills_pnl(list(fills))
        fees_perp += float(summary.get("fees_perp") or 0)
        fees_option += float(summary.get("fees_option") or 0)
        # LIVE 不展示、不计入滑点；按组成交模式判断（可混有历史 SIM 组）
        exec_mode = str(r["exec_mode"] or mode).upper()
        if exec_mode != "LIVE":
            total_slip += float(summary.get("slip_total") or 0)

    total_fees = fees_perp + fees_option
    reasons: dict[str, int] = {}
    for r in rows:
        k = str(r["close_reason"] or "unknown")
        reasons[k] = reasons.get(k, 0) + 1
    curve = [
        {
            "group_id": r["group_id"],
            "realized_pnl": float(r["realized_pnl"] or 0),
            "close_at_ms": r["close_at_ms"],
        }
        for r in sorted(rows, key=lambda x: int(x["close_at_ms"] or 0))
    ]
    latest_funds = 0.0
    try:
        from ..sim.funds_wallets import FundsWallets

        latest_funds = float(FundsWallets(database).total_usdt_equiv())
    except Exception:
        try:
            from ..sim.ledger import Ledger

            latest_funds = float(Ledger(database).snapshot().get("equity") or 0)
        except Exception:
            latest_funds = 0.0

    try:
        initial_funds = float(
            database.get_setting("initial_equity", str(s.initial_equity))
            or s.initial_equity
        )
    except Exception:
        initial_funds = float(s.initial_equity)

    return {
        "mode": mode,
        "show_slip": mode == "SIM",
        "groups": n,
        "wins": wins,
        "win_rate": (wins / n) if n else 0.0,
        "total_pnl": total_pnl,
        "fees_perp": fees_perp,
        "fees_option": fees_option,
        "total_fees": total_fees,
        "total_slip": total_slip if mode == "SIM" else 0.0,
        "close_reasons": reasons,
        "equity_curve": curve,
        "initial_funds": initial_funds,
        "latest_funds": latest_funds,
        "max_single_loss": max_single_loss,
        "loss_streak": _current_loss_streak(curve),
    }


@router.get("/summary")
async def stats_summary(_user: Annotated[str, Depends(require_user)]) -> dict:
    return build_stats_summary()