# +======================================================================
# | DjangoAdmin 企业数字化开发平台 [ 赋能开发者，助力企业发展 ]
# +----------------------------------------------------------------------
# | Copyright (c) 2021-2026 一米阳光团队 版权所有
# | 开源协议: Apache-2.0
# +======================================================================
# 由 apps/__init__.py 迁移而来。

"""应用工厂：create_app 组装中间件、路由、异常处理与 lifespan。"""

import time

from fastapi import FastAPI
from fastapi.exceptions import RequestValidationError
from fastapi.logger import logger
from starlette.requests import Request
from starlette.responses import JSONResponse

from config.app import FASTAPI_DEBUG
from core.exceptions import AuthorizationException, BusinessException
from core.middleware import (
    register_middleware,
    register_cros,
    db_session_middleware,
    operation_log_middleware,
)
from core.redis_client import redis_lifespan, redis_middleware
from routers import register_router


def create_app() -> FastAPI:
    app = FastAPI(
        title="FastAPI",
        description="FastAPI",
        version="v1",
        lifespan=redis_lifespan,
    )

    # 注册跨域中间件
    register_cros(app)
    # 注册Redis上下文注入中间件（先注册→内层：先注入Redis再开DB会话）
    app.middleware("http")(redis_middleware)
    # 注册数据库会话中间件（后注册→外层：DB会话包裹业务逻辑，finally保证关闭）
    app.middleware("http")(db_session_middleware)
    # 注册操作日志中间件（在DB会话内层，记录写操作日志）
    app.middleware("http")(operation_log_middleware)
    # 注册路由
    register_router(app)
    # 登录检测
    register_middleware(app)
    # 注册全局异常处理
    register_exception(app)

    # 请求计时（最后注册→最外层，统计完整耗时）
    @app.middleware("http")
    async def add_process_time_header(request: Request, call_next):
        start_time = time.time()
        response = await call_next(request)
        process_time = time.time() - start_time
        response.headers["X-Process-Time"] = str(round(process_time, 5))
        if FASTAPI_DEBUG:
            logger.info(f"访问记录:{request.method} url:{request.url}  耗时:{str(round(process_time, 5))}")
        return response

    return app


# 注册全局异常处理
def register_exception(app: FastAPI):
    """全局异常捕获。"""

    @app.exception_handler(AuthorizationException)
    async def unicorn_exception_handler(request: Request, exc: AuthorizationException):
        return JSONResponse(
            status_code=200,
            content={"code": exc.code, "data": None, "msg": exc.msg, "ok": False},
        )

    @app.exception_handler(BusinessException)
    async def business_exception_handler(request: Request, exc: BusinessException):
        return JSONResponse(
            status_code=200,
            content={"code": exc.code, "data": None, "msg": exc.msg, "ok": False},
        )

    @app.exception_handler(RequestValidationError)
    async def validation_exception_handler(request: Request, exc: RequestValidationError):
        errors = []
        for err in exc.errors():
            field = err.get("loc", [""])[-1]
            msg = err.get("msg", "")
            if field and field != "body":
                errors.append(f"{field}: {msg}")
            else:
                errors.append(msg)
        return JSONResponse(
            status_code=200,
            content={"code": 1, "data": None, "msg": "/".join(errors)},
        )