# !/usr/bin/env python3
# -*- encoding : utf-8 -*-
# @Filename    : __init__.py
# @Software    : VSCode
# @Datetime    : 2021/11/03 16:59:57
# @Author      : leo liu
# @Version     : 1.0
# @Description :

import traceback
from fastapi import FastAPI, Request, status, HTTPException
from fastapi.encoders import jsonable_encoder
from fastapi.responses import JSONResponse
from fastapi.exceptions import RequestValidationError
from fastapi.middleware.cors import CORSMiddleware

# from slowapi import Limiter
# from slowapi.util import get_remote_address
# from slowapi.middleware import SlowAPIMiddleware

from api.v1 import api_v1
from extensions import logger
from core.settings import config
from utils.custom_exc import PostParamsError, TokenAuthError  # 自定义异常

# swigger 文档分类 https://fastapi.tiangolo.com/tutorial/metadata/
tags_metadata = [
    {
        "name": "首页",
        "description": "数据API",
    },
]

def create_app():
    app = FastAPI(
        title="Chatmed",
        description="",
        version="0.0.1",
        docs_url=config.DOCS_URL,
        openapi_url=config.OPENAPI_URL,
        redoc_url=config.REDOC_URL,
        openapi_tags=tags_metadata
    )

    app.include_router(
        api_v1,
        prefix="/api/v1",
    )

    register_exception(app)  # 注册捕获异常信息
    register_cors(app)  # 跨域设置
    register_middleware(app)

    return app

def register_exception(app: FastAPI):
    """
    全局异常捕获
    :param app:
    :return:
    """

    # 捕获自定义异常
    @app.exception_handler(PostParamsError)
    async def query_params_exception_handler(request: Request, exc: PostParamsError):
        """
        捕获 自定义抛出的异常
        :param request:
        :param exc:
        :return:
        """
        logger.error(f"参数查询异常\nURL:{request.url}\nHeaders:{request.headers}\n{traceback.format_exc()}")
        return JSONResponse(
            status_code=status.HTTP_400_BAD_REQUEST,
            content={"code": 400, "data": {"tip": exc.err_desc}, "message": "fail"},
        )

    @app.exception_handler(TokenAuthError)
    async def token_exception_handler(request: Request, exc: TokenAuthError):
        logger.error(f"参数查询异常\nURL:{request.url}\nHeaders:{request.headers}\n{traceback.format_exc()}")
        return JSONResponse(
            status_code=status.HTTP_400_BAD_REQUEST,
            content={"code": 400, "data": None, "message": exc.err_desc},
        )

    # 捕获参数 验证错误
    @app.exception_handler(RequestValidationError)
    async def validation_exception_handler(request: Request, exc: RequestValidationError):
        """
        捕获请求参数 验证错误
        :param request:
        :param exc:
        :return:
        """
        logger.error(f"参数错误\nURL:{request.url}\nHeaders:{request.headers}\n{traceback.format_exc()}")
        return JSONResponse(
            status_code=status.HTTP_400_BAD_REQUEST,
            content=jsonable_encoder({"code": 400, "data": {"tip": exc.errors()}, "body": exc.body, "message": "fail"}),
        )

    # 捕获全部异常
    @app.exception_handler(Exception)
    async def all_exception_handler(request: Request, exc: Exception):
        logger.error(f"全局异常\nURL:{request.url}\nHeaders:{request.headers}\n{traceback.format_exc()}")
        return JSONResponse(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            content={"code": 500, "data": {"tip": "服务器错误"}, "message": "fail"},
        )

    # 捕获调用超限异常
    # @app.exception_handler(HTTPException)
    # async def rate_limit_handler(request, exc):
    #     if exc.status_code == 429:
    #         return JSONResponse(status_code=status.HTTP_429_TOO_MANY_REQUESTS,
    #         content={"code": 429, "data": "我还在处理您的问题，请稍后再试！", "message": "to many requests"},)
    #     return JSONResponse(
    #         status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
    #         content={"code": 500, "data": {"tip": "服务器错误"}, "message": "fail"},
    #     )

def register_cors(app: FastAPI):
    """
    支持跨域

    貌似发现了一个bug
    https://github.com/tiangolo/fastapi/issues/133

    :param app:
    :return:
    """

    app.add_middleware(
        CORSMiddleware,
        # allow_origins=['http://localhost:8081'],  # 有效, 但是本地vue端口一直在变化, 接口给其他人用也不一定是这个端口
        # allow_origins=['*'],   # 无效 bug allow_origins=['http://localhost:8081']
        allow_origin_regex='https?://.*',  # 改成用正则就行了
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

def register_middleware(app: FastAPI):
    """
    请求响应拦截 hook

    https://fastapi.tiangolo.com/tutorial/middleware/
    :param app:
    :return:
    """

    @app.middleware("http")
    async def logger_request(request: Request, call_next):
        # https://stackoverflow.com/questions/60098005/fastapi-starlette-get-client-real-ip
        logger.info(f"访问记录:{request.method} url:{request.url}\nheaders:{request.headers.get('user-agent')}"
                    f"\nIP:{request.client.host}")

        response = await call_next(request)

        return response