import traceback
from multiprocessing import freeze_support
from typing import List

from flask import Flask, jsonify, request
from flask_cors import CORS
from flask_sock import Sock
from werkzeug.serving import ThreadedWSGIServer

from Backend.consensus import *


class Backend:

    def __init__(self, name, domain="0.0.0.0", port=0, debug=False):
        # 网络配置
        self.port = port
        self.domain = domain
        # 后端app
        self.app = Flask(name)
        self.sock = Sock(self.app)
        # 跨域配置
        CORS(self.app, supports_credentials=True)
        self.app.debug = debug
        # 基本地址
        self.base_url = '/'
        # 获得系统状态
        self.register(name="system_status", func=self.system_status, methods=[REQUEST_MODE_GET])
        self.register(name="post_test", func=self.post_test, methods=[REQUEST_MODE_POST])

    # 注册后端接口
    def register(self, name, func, methods: List):
        self.app.add_url_rule(
            rule=f"{self.base_url}{name}",
            methods=methods,
            view_func=func,
            endpoint=name
        )

    # 注册WebSocket接口
    def register_websocket(self, name, func):
        @self.sock.route(f"{self.base_url}{name}", endpoint=name)
        def sock_func(ws):
            func(ws)

    @staticmethod
    def system_status():
        try:
            return jsonify({"status": STATUS_OK})
        except Exception as e:
            error_msg = {
                "status": STATUS_UNKNOWN_ERROR,
                "error_message": f"后端系统启动失败({e.args})，错误来源：{traceback.format_exc()}"
            }
            return jsonify(error_msg)

    @staticmethod
    def post_test():
        try:
            data = request.get_json()
            return jsonify({"status": STATUS_OK, "post_data": data})
        except Exception as e:
            error_msg = {
                "status": STATUS_UNKNOWN_ERROR,
                "error_message": f"后端系统错误({e.args})，错误来源：{traceback.format_exc()}"
            }
            return jsonify(error_msg)

    def start_backend(self):
        server = ThreadedWSGIServer(app=self.app, port=self.port, host=self.domain)
        server.serve_forever(0.001)