from contextlib import asynccontextmanager

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

from app.api.v1 import documents, export, export_records
from app.core.exceptions import register_exception_handlers
from app.services.storage_monitor import start_background_monitor


@asynccontextmanager
async def lifespan(app: FastAPI):
    # 启动后台磁盘监控（每 30 分钟检查一次）
    monitor_task = start_background_monitor()
    yield
    # 关闭时取消后台任务
    monitor_task.cancel()


def create_app() -> FastAPI:
    app = FastAPI(
        title="Axonix Text Editor API",
        version="0.1.0",
        description="文本编辑器后端 API —— 阶段 0：文档 CRUD + 导出下载",
        lifespan=lifespan,
    )

    # CORS（开发阶段放开，生产按需收紧）
    app.add_middleware(
        CORSMiddleware,
        allow_origins=["*"],
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    # 全局异常处理
    register_exception_handlers(app)

    # 路由注册
    app.include_router(documents.router, prefix="/api/v1")
    app.include_router(export.router, prefix="/api/v1")
    app.include_router(export_records.router, prefix="/api/v1")

    return app


app = create_app()