from contextlib import asynccontextmanager
from pathlib import Path
import logging

from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles

from app.engine.config import STATIC_DIR
from app.platform.host_middleware import TenantHostMiddleware
from app.platform.registry import TenantRegistry

logger = logging.getLogger(__name__)

# 路径锚定(不随 CWD 漂移):seed_profiles 与 tenants 都在仓库根
BASE_DIR = Path(__file__).resolve().parents[1]
SEED_DIR = BASE_DIR / "seed_profiles"
TENANTS_DIR = BASE_DIR / "tenants"        # .gitignore 已忽略 tenants/*.db


@asynccontextmanager
async def lifespan(app: FastAPI):
    # 测试注入缝:conftest 预置过 app.state.registry(临时 data_dir 的独立
    # Registry)则沿用,不再加载仓库 seed——测试租户库与生产互不污染
    registry = getattr(app.state, "registry", None)
    if registry is None:
        registry = TenantRegistry.load_from_dir(SEED_DIR, data_dir=TENANTS_DIR)
        app.state.registry = registry

    try:
        # 询盘推送(设计 8.2): 清扫崩溃遗留的 stale pending → failed。逐租户、
        # 用该租户自己的 session_factory;db 文件不存在的租户跳过——全新库
        # 无遗留行,保持 engine 懒建纪律(租户 engine 由 Host 中间件按请求
        # 懒建,启动期只有已有库文件的租户会被扫描)。
        # 清扫失败只记日志继续:一个租户的坏库不炸整个平台启动(其余租户
        # 照常服务),该租户下轮重启还会重扫。
        from app.engine.services.lead_push_service import sweep_stale_pending
        for rt in registry.runtimes():
            if rt.config.status != "active" or not rt.db_path.exists():
                continue
            try:
                ready = await registry.ensure_ready(rt)
                await sweep_stale_pending(session_factory=ready.session_factory)
            except Exception:
                logger.exception(
                    "启动清扫失败,跳过该租户(slug=%s, db=%s)",
                    rt.config.slug, rt.db_path)

        yield
    finally:
        # 幂等于"更少的引擎":启动半途失败也把已建好的 engine 关掉
        # (Windows 文件锁: 不关则库文件删不掉)
        await registry.dispose_all()


app = FastAPI(title="HESUPIPE AI 客服", lifespan=lifespan)

from app.engine.routes.chat import router as chat_router
from app.engine.routes.chat_rest import router as chat_rest_router
app.include_router(chat_router)
app.include_router(chat_rest_router)

app.mount("/static", StaticFiles(directory=str(STATIC_DIR)), name="static")


@app.middleware("http")
async def static_no_cache(request, call_next):
    """静态资源协商缓存(2026-09-30 线上事件): 无 Cache-Control 时浏览器对
    widget.js 走启发式缓存,修复部署后用户端仍跑旧脚本。no-cache=每次用
    etag 轻量协商,有更新即时生效,未变则 304 几乎零开销。"""
    resp = await call_next(request)
    if request.url.path.startswith("/static/"):
        resp.headers["Cache-Control"] = "no-cache"
    return resp


# 租户路由中间件(Task 7): 最后 add = 最外层——租户解析先于一切用户中间件。
# 纯 ASGI 类(http+websocket 双覆盖),registry 经 scope["app"] 延迟取,
# 因此可在 lifespan 挂 Registry 之前于模块级注册。
app.add_middleware(TenantHostMiddleware)


@app.get("/")
async def index():
    from fastapi.responses import FileResponse
    return FileResponse(str(STATIC_DIR / "chat.html"))


@app.get("/health")
async def health():
    return {"status": "ok"}