from collections.abc import AsyncGenerator
from typing import Any

from fastapi import FastAPI
from fastapi.concurrency import asynccontextmanager
from fastapi.openapi.docs import get_redoc_html, get_swagger_ui_html, get_swagger_ui_oauth2_redirect_html
from fastapi.responses import HTMLResponse
from fastapi.staticfiles import StaticFiles

from .common.enums import EnvironmentEnum
from .config import path_conf
from .config.setting import settings
from .core.exceptions import handle_exception
from .core.logger import logger
from .utils.common_util import import_module
from .utils.console import console_end, console_start


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncGenerator[Any, Any]:
    from app.api.v1.module_system.dict.service import DictDataService
    from app.api.v1.module_system.params.service import ParamsService
    from app.core.ap_scheduler import SchedulerUtil
    from app.core.database import async_engine, redis_connect
    from app.scripts.initialize import InitializeData

    await InitializeData().init_db()
    logger.info("✅ {}数据库初始化完成", settings.DATABASE_TYPE)

    # Redis 启动不强依赖：连接失败降级启动（参数/字典读接口回源数据库，
    # 登录会话/在线监控/AI配置/调度任务等存储类接口返回 503），不再中断应用。
    await redis_connect(app, status=True)
    redis_ready = app.state.redis is not None
    if redis_ready:
        logger.info("✅ Redis 连接初始化完成")
        await ParamsService.init_cache(redis=app.state.redis)
        logger.info("✅ Redis系统参数初始化完成")
        await DictDataService.init_cache(redis=app.state.redis)
        logger.info("✅ Redis数据字典初始化完成")
    else:
        logger.warning(
            "⚠️ Redis 不可用，以降级模式启动：参数/字典读接口回源数据库；"
            "登录会话/在线监控/AI配置接口将返回 503（调度任务 jobstore 已落 PG，不受影响）"
        )

    from app.utils.dict_util import preload_value2label_cache

    await preload_value2label_cache()
    logger.info("✅ 数据字典导出映射预载完成")

    scheduler_ready = False
    try:
        await SchedulerUtil.init_scheduler()
        scheduler_ready = SchedulerUtil.is_running()
        logger.info("✅ 定时任务调度器初始化完成")
    except Exception as e:
        # 调度器初始化失败（jobstore 已落 PG，与主库同生共死）：不阻断启动
        SchedulerUtil.shutdown(wait=False)
        logger.error("❌ 定时任务调度器初始化失败（继续启动，任务接口将返回 503）: {}", e)

    console_start(
        host=settings.SERVER_HOST,
        port=settings.SERVER_PORT,
        reload=settings.DEBUG,
        database_ready=True,
        redis_ready=redis_ready,
        scheduler_ready=scheduler_ready,
    )

    yield

    try:
        SchedulerUtil.shutdown(wait=True)
        logger.info("✅ 定时任务调度器已关闭")
        await redis_connect(app, status=False)
        logger.info("✅ Redis 连接已关闭")
        await async_engine.dispose()
        logger.info("✅ 数据库引擎连接池已释放")
        console_end()
    except Exception as e:
        logger.error("❌ 应用关闭过程中发生错误: {}", e)
        raise SystemExit(1)


def register_middlewares(app: FastAPI) -> None:
    for middleware in settings.MIDDLEWARE_LIST[::-1]:
        if not middleware:
            continue
        middleware = import_module(middleware, desc="中间件")
        app.add_middleware(middleware)


def register_exceptions(app: FastAPI) -> None:
    handle_exception(app)


def register_routers(app: FastAPI) -> None:
    from app.api.v1.module_ai import ai_router
    from app.api.v1.module_bre import bre_router
    from app.api.v1.module_bre.brapi.controller import brapi_router
    from app.api.v1.module_common import common_router
    from app.api.v1.module_generator import generator_router
    from app.api.v1.module_monitor import monitor_router
    from app.api.v1.module_system import system_router
    from app.api.v1.module_task import task_router

    app.include_router(common_router)
    app.include_router(monitor_router)
    app.include_router(system_router)
    app.include_router(ai_router)
    app.include_router(generator_router)
    app.include_router(task_router)
    app.include_router(bre_router)
    app.include_router(brapi_router)

    from app.core.discover import dynamic_router
    dynamic_router.init_app(app)


def register_static(app: FastAPI) -> None:
    """注册静态文件路由。"""
    path_conf.STATIC_DIR.mkdir(parents=True, exist_ok=True)
    app.mount(path=settings.STATIC_URL, app=StaticFiles(directory=path_conf.STATIC_DIR), name=path_conf.STATIC_DIR.name)


def register_docs(app: FastAPI) -> None:
    """注册文档路由。

    生产环境不注册 /docs /redoc：避免暴露全部接口定义（攻击者据此定位薄弱点）。
    """
    if settings.ENVIRONMENT == EnvironmentEnum.PROD:
        return
    swagger_ui_redirect_url = str(app.swagger_ui_oauth2_redirect_url)
    root_openapi_url = str(app.root_path) + str(app.openapi_url)

    @app.get(swagger_ui_redirect_url, include_in_schema=False)
    async def swagger_ui_redirect():
        return get_swagger_ui_oauth2_redirect_html()

    @app.get(settings.DOCS_URL, include_in_schema=False)
    async def custom_swagger_ui_html() -> HTMLResponse:
        return get_swagger_ui_html(
            openapi_url=root_openapi_url,
            title=app.title + " - Swagger UI",
            oauth2_redirect_url=app.swagger_ui_oauth2_redirect_url,
            swagger_js_url=settings.SWAGGER_JS_URL,
            swagger_css_url=settings.SWAGGER_CSS_URL,
            swagger_favicon_url=settings.FAVICON_URL,
        )

    @app.get(settings.REDOC_URL, include_in_schema=False)
    async def custom_redoc_html():
        return get_redoc_html(
            openapi_url=root_openapi_url,
            title=app.title + " - ReDoc",
            redoc_js_url=settings.REDOC_JS_URL,
            redoc_favicon_url=settings.FAVICON_URL,
        )


def register_frontend(app: FastAPI) -> None:
    if path_conf.FRONTEND_DIST_DIR.exists():
        app.mount("/web", StaticFiles(directory=str(path_conf.FRONTEND_DIST_DIR), html=True), name="frontend")