from __future__ import annotations

import logging
from contextlib import asynccontextmanager
from pathlib import Path

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse
from fastapi.staticfiles import StaticFiles

from .api import router as api_router
from .config import get_settings
from .models.db import Database, set_db
from .strategy import StrategyEngine, set_engine
from .strategy.session import bootstrap_session

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s [%(name)s] %(message)s",
)
logger = logging.getLogger("eth_hedge_sim")


def resolve_frontend_dist() -> Path:
    here = Path(__file__).resolve()
    repo_root = here.parents[2]
    return repo_root / "frontend" / "dist"


@asynccontextmanager
async def lifespan(app: FastAPI):
    db = Database()
    set_db(db)
    # 必须在 set_db 之后读 DB 覆盖，否则会按 .env 默认 okx 起会话，
    # 而 health 显示 DB 里的 binance → 合约号/盘口错乱（期权一直 -/-）
    from .exchange.runtime import load_runtime_settings

    app_settings = get_settings()
    if not app_settings.is_sim:
        secret = (app_settings.auth_secret or "").strip()
        if not secret or secret == "change-me-eth-hedge-sim-secret":
            raise RuntimeError(
                "LIVE 拒绝启动：请在 .env 设置非默认 AUTH_SECRET（勿用 change-me-eth-hedge-sim-secret）"
            )

    settings = load_runtime_settings()
    engine = StrategyEngine()
    set_engine(engine)
    # 半自动：无仓时清陈旧授权，须首页重新「授权开下一单」
    try:
        from .strategy.semi_auto import clear_armed_if_flat

        clear_armed_if_flat(
            db, has_open_position=engine.matcher.has_open_position()
        )
    except Exception:
        logger.exception("clear stale semi_armed on startup failed")
    # LIVE：进程启动后不自动真下单，须人工点「启动」
    if not get_settings().is_sim:
        try:
            db._conn.execute(
                "UPDATE strategy_state SET running=0, phase=? WHERE id=1",
                ("paused",),
            )
            db._conn.commit()
            logger.info("LIVE startup: forced strategy pause (manual start required)")
        except Exception:
            logger.exception("LIVE startup force-pause failed")
        try:
            from .live import get_executor
            from .live.reconcile import log_exchange_db_mismatch

            log_exchange_db_mismatch(get_executor(db))
        except Exception:
            logger.exception("LIVE startup reconcile log failed")
    engine.ensure_loop()

    from .backup import start_auto_backup_task

    start_auto_backup_task()

    session = bootstrap_session(settings)
    try:
        await session.start()
        logger.info(
            "exchange=%s strategy session started mode=%s",
            settings.exchange,
            "SIM" if get_settings().is_sim else "LIVE",
        )
    except Exception:
        logger.exception("strategy session failed to start")

    yield

    await engine.pause()
    if engine._task and not engine._task.done():
        engine._task.cancel()
        try:
            await engine._task
        except Exception:
            pass
    from .backup import stop_auto_backup_task

    await stop_auto_backup_task()
    await session.stop()
    from .exchange import set_exchange
    from .strategy.session import set_session

    set_session(None)
    set_exchange(None)
    set_engine(None)
    db.close()
    set_db(None)


app = FastAPI(
    title="比特骆驼自动化对冲系统",
    version="0.3.1",
    description="比特骆驼自动化对冲系统（eth_hedge_sim）",
    lifespan=lifespan,
    docs_url=None if get_settings().disable_api_docs else "/docs",
    redoc_url=None if get_settings().disable_api_docs else "/redoc",
    openapi_url=None if get_settings().disable_api_docs else "/openapi.json",
)
app.add_middleware(
    CORSMiddleware,
    allow_origins=[],
    allow_credentials=False,
    allow_methods=["*"],
    allow_headers=["*"],
)
app.include_router(api_router)


@app.get("/health")
async def health() -> dict:
    from .strategy import get_engine
    from .strategy.session import get_session

    settings = get_settings()
    try:
        from .exchange.runtime import load_runtime_settings

        rt = load_runtime_settings()
        exchange_name = rt.exchange
    except Exception:
        exchange_name = settings.exchange
    sess = get_session()
    snap = sess.snapshot()
    try:
        st = get_engine().state()
    except Exception:
        st = None
    return {
        "ok": True,
        "mode": settings.mode,
        "env_name": settings.env_name,
        "exchange": exchange_name,
        "sim": settings.is_sim,
        "market_connected": snap.connected,
        "pair": snap.pair.to_dict() if snap.pair else None,
        "updated_at_ms": snap.updated_at_ms,
        "strategy": {
            "running": st.get("running") if st else None,
            "phase": st.get("phase") if st else None,
            "rounds_done": st.get("rounds_done") if st else None,
        },
    }


_DIST = resolve_frontend_dist()
if (_DIST / "assets").is_dir():
    app.mount("/assets", StaticFiles(directory=str(_DIST / "assets")), name="assets")

_ICONS = _DIST / "icons"
if _ICONS.is_dir():
    app.mount("/icons", StaticFiles(directory=str(_ICONS)), name="icons")


def _dist_file(name: str) -> Path:
    return _DIST / name


@app.get("/manifest.webmanifest")
async def web_manifest():
    path = _dist_file("manifest.webmanifest")
    if not path.exists():
        raise HTTPException(status_code=404, detail="manifest missing")
    return FileResponse(
        path,
        media_type="application/manifest+json",
        headers={"Cache-Control": "no-cache"},
    )


@app.get("/sw.js")
async def service_worker():
    path = _dist_file("sw.js")
    if not path.exists():
        raise HTTPException(status_code=404, detail="service worker missing")
    return FileResponse(
        path,
        media_type="application/javascript",
        headers={
            "Cache-Control": "no-cache",
            "Service-Worker-Allowed": "/",
        },
    )


@app.get("/")
async def index_page():
    index = _DIST / "index.html"
    if index.exists():
        return FileResponse(index)
    return {
        "ok": True,
        "msg": "frontend not built yet; run: cd frontend && npm ci && npm run build",
        "health": "/health",
    }


@app.get("/app/{full_path:path}")
@app.get("/plan")
@app.get("/trades")
@app.get("/stats")
@app.get("/settings")
@app.get("/login")
@app.get("/fleet-login")
async def spa_pages(full_path: str = ""):
    index = _DIST / "index.html"
    if not index.exists():
        raise HTTPException(status_code=404, detail="frontend not built")
    return FileResponse(index)