import express from "express";
import http from "http";
import log4js from "log4js";
import { Server } from "socket.io";
import { loadHistory, saveToDatabase, queryHistory, getDatabaseState } from "./storage.js";

const PORT = process.env.PORT || 5691;


const app = express();
const server = http.createServer(app);
const io = new Server(server, {
  cors: {
    origin: "*",
    methods: ["GET", "POST"],
  },
});

const logger = log4js.getLogger("app");

app.use(express.static("static"))
logger.level = process.env.LOG_LEVEL || "debug";

// 初始化在线列表
let onlineList = [];
let clientMap = new Map();

class Response {
    constructor(status, msg) {
        this.status = status
        this.msg = msg
    }
}

app.get("/online", (req, res) => {
    res.status(200).send({
        online: onlineList.length,
        user: onlineList
    })
})

app.get("/history", (req, res) => {
    if (!getDatabaseState()) {
        res.status(500).send({
            status: 500,
            msg: "database is not ready",
            data: null
        })
    }
    if (!req.query.limit || isNaN(req.query.limit) || req.query.limit <= 0 || req.query.limit > 100) {
        req.query.limit = 10;
    }
    loadHistory(req.query.limit).then((data) => {
        res.status(200).send({
            status: 200,
            msg: "success",
            data: data
        })
    }).catch((err) => {
        logger.error(`database error: ${err}`)
        res.status(500).send({
            status: 500,
            msg: "database error",
            data: null
        })
    })
})

io.on("connection", (socket) => {
    logger.info(`A client connected, id: ${socket.id}`)
    socket.on("system", data => {
        if (!data) {
            socket.emit("system", JSON.stringify(new Response(false, "data payload is empty.")))
            return;
        }
        if (clientMap.has(socket.id)) {
            socket.emit("system", JSON.stringify(new Response(false, "you are already online.")))
            return;
        }
        try {
            const { opt, args } = JSON.parse(data);
            console.log(opt, args)
            if (opt == "signin") {
                if (!args || !args.username) {
                    socket.emit("system", JSON.stringify(new Response(false, "username is empty.")))
                    return;
                }
                const { username } = args
                if (username.length > 20) {
                    socket.emit("system", JSON.stringify(new Response(false, "username is too long.")))
                }
                if (onlineList.indexOf(username) != -1) {
                    socket.emit("system", JSON.stringify(new Response(false, "username is already taken.")))
                    return;
                }
                socket.username = username;
                onlineList.push(username);
                clientMap.set(socket.id, username);
                socket.emit("username", socket.username);
                socket.emit("system", JSON.stringify(new Response(true, `welcome, ${socket.username}`)))
                io.emit("notice", JSON.stringify(new Response(true, `${socket.username} join the chat.`)))
                logger.debug(`socket(${socket.id}) -- ${username} signed in.`)
            }
            
        } catch (err) {
            logger.error(`socket(${socket.id}) -- ${err}.`)
            socket.emit("system", JSON.stringify(new Response(false, "data payload is invaild.")))
            return;
        }
        console.log(clientMap)
        console.log(onlineList)
    })

    socket.on("msg", data => {
        if (!socket.username) {
            socket.emit("system", JSON.stringify(new Response(false, "you are not signed in.")));
            return;
        }
        logger.debug(`socket(${socket.id}) -- ${data}`)
        io.emit("msg", JSON.stringify({sender: socket.username, msg: data}))
        saveToDatabase(socket.username, data, new Date().getTime())
    })

    socket.on("disconnect", (reason, description) => {
        logger.info(`A client disconnected, id: ${socket.id}`)
        logger.trace(`socket(${socket.id}) -- reason: ${reason}, description: ${description}`);
        if (clientMap.has(socket.id)) clientMap.delete(socket.id);
        // TODO: 这个算法有点不安全
        if (onlineList.includes(socket.username)) onlineList.splice(onlineList.indexOf(socket.id));
        io.emit("notice", JSON.stringify(new Response(true, `${socket.username} left the chat.`)));
    })
});

server.listen(PORT, () => {
  logger.info(`Server running on port ${PORT}`);
});