from fastapi import WebSocket,WebSocketDisconnect
import random
import os
import websockets.exceptions
import asyncio

class Manager(object):
    def __init__(self,file_dict):
        self.active_websocket = []
        self.file_dict = file_dict

    def search_file(self,file_name):
        for pj_name,path in self.file_dict.items():
            if file_name in os.listdir(path):
                return os.path.join(path,file_name)
        return None

    async def connect(self,websocket:WebSocket):
        await websocket.accept()
        self.active_websocket.append(websocket)

    async def disconnect(self,websocket:WebSocket):
        self.active_websocket.remove(websocket)

    async def send_personal_message(self,content:str,websocket:WebSocket):
        await websocket.send_text(content)

    async def broadcast(self,content:str):
        for websocket in self.active_websocket:
            await websocket.send_text(content)

    async def read_suff_n_lines(self,f,n=5,file_size=None,size=1024):
        multy = 1
        pos = file_size - size*multy
        while True:
            f.seek(pos,0)
            lines = f.readlines()
            if len(lines)<5:
                multy += 1
                pos = file_size - size*multy
            else:
                break
        return [line.strip() for line in lines][-5:]

    async def ws_handler(self,websocket:WebSocket,file_name):
        file_path = self.search_file(file_name)
        print("file-path:",file_path)
        if not file_path:
            raise Exception("文件不存在")
        f = open(file_path,encoding="utf-8")
        file_size = f.seek(0, 2)
        suff_lines = await self.read_suff_n_lines(f,5,file_size)
        f.seek(0, 2)
        await self.connect(websocket)
        try:
            for content in suff_lines:
                await self.send_personal_message(content, websocket)
            while True:
                line = f.readline().strip()
                if not line:
                    await asyncio.sleep(0.1)
                content = line
                await self.send_personal_message(content, websocket)
                await asyncio.sleep(0.1)
        except (WebSocketDisconnect,websockets.exceptions.ConnectionClosedError,websockets.exceptions.ConnectionClosedOK) as WebDis :
            print("webDis",str(WebDis))
            await self.disconnect(websocket)
        finally:
            f.close()