"""FastAPI 应用入口"""

import os
import sys
from contextlib import asynccontextmanager
from pathlib import Path

from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
from fastapi.staticfiles import StaticFiles

from app.config import get_config, Config
from app.database import init_db, get_connection


@asynccontextmanager
async def lifespan(app: FastAPI):
    """应用生命周期：启动时初始化，关闭时清理"""
    # 启动
    config = app.state.config
    config.data_dir.mkdir(parents=True, exist_ok=True)
    config.problems_dir.mkdir(parents=True, exist_ok=True)
    config.papers_dir.mkdir(parents=True, exist_ok=True)
    config.backups_dir.mkdir(parents=True, exist_ok=True)

    init_db(config.db_path)
    print(f"✓ 数据库已初始化: {config.db_path}")
    print(f"✓ API Token: {config.token}")
    print(f"✓ 服务启动在 http://{config.host}:{config.port}")

    yield


def create_app(config: Config) -> FastAPI:
    app = FastAPI(
        title="题库PLUS",
        description="C/S 架构数学题库管理系统",
        version="1.0.0",
        lifespan=lifespan,
    )

    app.state.config = config

    # CORS
    app.add_middleware(
        CORSMiddleware,
        allow_origins=["*"],
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    # 全局异常处理
    @app.exception_handler(Exception)
    async def global_exception_handler(request: Request, exc: Exception):
        import traceback
        traceback.print_exc()
        return JSONResponse(
            status_code=500,
            content={"error": {"code": "internal_error", "message": str(exc)}},
        )

    # 注册路由
    from app.routers import auth, problems, import_, export_, knowledge, carts, admin
    app.include_router(auth.router, prefix="/api", tags=["auth"])
    app.include_router(problems.router, prefix="/api", tags=["problems"])
    app.include_router(import_.router, prefix="/api", tags=["import"])
    app.include_router(export_.router, prefix="/api", tags=["export"])
    app.include_router(knowledge.router, prefix="/api", tags=["knowledge"])
    app.include_router(carts.router, prefix="/api", tags=["carts"])
    app.include_router(admin.router, prefix="/api", tags=["admin"])

    # Flutter Web 静态文件
    web_dir = Path("web")
    if web_dir.exists() and any(web_dir.iterdir()):
        app.mount("/", StaticFiles(directory=str(web_dir), html=True), name="web")

    return app


def main():
    """CLI 入口"""
    if len(sys.argv) < 2:
        print("用法: tiku-server <命令> [参数]")
        print()
        print("命令:")
        print("  serve              启动服务")
        print("  serve --restart    启动服务（崩溃/更新后自动重启）")
        print("  knowledge build    重建知识点编码")
        print("  rebuild-index      手动增量索引")
        print("  stats              终端统计")
        print("  backup             手动备份")
        print("  backup --remote    推送到 WebDAV")
        print("  token              显示/重新生成 API token")
        print("  token regenerate   重新生成 API token")
        sys.exit(1)

    cmd = sys.argv[1]
    config_path = os.environ.get("TIKU_CONFIG", "config.yaml")
    cfg = get_config(config_path)

    if cmd == "serve":
        import uvicorn
        auto_restart = len(sys.argv) > 2 and sys.argv[2] == "--restart"

        def run():
            uvicorn.run(
                create_app(cfg),
                host=cfg.host,
                port=cfg.port,
                log_level="info",
            )

        if auto_restart:
            import time as _time
            while True:
                print(f"{_time.strftime('%Y-%m-%d %H:%M:%S')} 启动服务端...")
                run()
                print(f"{_time.strftime('%Y-%m-%d %H:%M:%S')} 服务端退出，2 秒后重启...")
                _time.sleep(2)
        else:
            run()
    elif cmd == "knowledge":
        if len(sys.argv) > 2 and sys.argv[2] == "build":
            from app.services.knowledge import build_knowledge
            build_knowledge(cfg)
    elif cmd == "rebuild-index":
        from app.services.indexer import incremental_update
        incremental_update(cfg)
    elif cmd == "stats":
        from app.services.indexer import show_stats
        show_stats(cfg)
    elif cmd == "backup":
        remote = len(sys.argv) > 2 and sys.argv[2] == "--remote"
        from app.services.backup import manual_backup
        manual_backup(cfg, remote=remote)
    elif cmd == "token":
        action = sys.argv[2] if len(sys.argv) > 2 else "show"
        if action == "regenerate":
            new_token = cfg.regenerate_token()
            print(f"新 Token: {new_token}")
        else:
            print(f"Token: {cfg.token}")
    else:
        print(f"未知命令: {cmd}")
        sys.exit(1)


if __name__ == "__main__":
    main()