"""FastAPI 应用工厂。"""
from __future__ import annotations

import logging
from collections.abc import AsyncIterator
from contextlib import asynccontextmanager

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from src.core.config import settings

logger = logging.getLogger(__name__)


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncIterator[None]:
    from src.db.base import init_db
    from src.core.http_client import close_client
    from src.core.runtime_config import (
        ensure_admin_password_hashed,
        migrate_plaintext_sensitive_settings,
    )
    from src.core.security_check import assert_security_on_startup
    await init_db()  # 验证连接,不建表
    await migrate_plaintext_sensitive_settings()  # 明文敏感配置 → 加密(幂等)
    await ensure_admin_password_hashed()  # .env 明文密码 → scrypt 哈希(幂等)
    await assert_security_on_startup()  # 启动安全校验(生产拒绝/开发警告)
    yield
    await close_client()


def create_app() -> FastAPI:
    from src.core.log_buffer import setup_memory_logging
    setup_memory_logging(settings.LOG_LEVEL)

    # 生产环境不暴露 OpenAPI 文档(避免向访客泄露接口结构)
    openapi_url = "/openapi.json" if settings.APP_ENV != "production" else None
    app = FastAPI(
        title="Profeto API",
        description="足球数据 + LLM 预测服务",
        version="0.1.0",
        lifespan=lifespan,
        openapi_url=openapi_url,
    )

    origins = [o.strip() for o in settings.CORS_ORIGINS.split(",") if o.strip()]
    methods = [m.strip() for m in settings.CORS_METHODS.split(",") if m.strip()]
    headers = [h.strip() for h in settings.CORS_HEADERS.split(",") if h.strip()]
    app.add_middleware(
        CORSMiddleware,
        allow_origins=origins,
        allow_credentials=True,
        allow_methods=methods,
        allow_headers=headers,
    )

    from src.api.routes.matches import router as matches_router
    from src.api.routes.predict import router as predict_router
    from src.api.routes.ingest import router as ingest_router
    from src.api.routes.eval import router as eval_router
    from src.api.routes.backtest import router as backtest_router
    from src.api.routes.auth import router as auth_router
    from src.api.routes.admin_settings import router as admin_settings_router

    app.include_router(matches_router)
    app.include_router(predict_router)
    app.include_router(ingest_router)
    app.include_router(eval_router)
    app.include_router(backtest_router)
    app.include_router(auth_router)
    app.include_router(admin_settings_router)

    @app.get("/health")
    async def health():
        return {"status": "healthy", "service": "profeto"}


    @app.get("/health/ready")
    async def health_ready():
        """就绪检查:验证数据库连接。

        数据库不可达时返回 HTTP 503,而非 200 + not_ready ——
        这样 K8s/Compose 的 readinessProbe 才能正确判定「未就绪」并停止流量。
        """
        from src.db.base import engine
        from fastapi.responses import JSONResponse
        try:
            async with engine.begin() as conn:
                await conn.run_sync(lambda conn: None)
            return {"status": "ready"}
        except Exception as e:
            logger.warning("就绪检查失败(数据库不可达): %s", e)
            return JSONResponse(
                status_code=503,
                content={"status": "not_ready", "reason": "database_unreachable"},
            )

    return app


app = create_app()