luzhanqi/server.js

const express = require('express')
const app = express()
app.use(express.static('public'))
const host = process.env.HOST || '0.0.0.0'
const port = process.env.PORT || 3000
const server = app.listen(port, host, () => console.log(`陆战棋游戏服务运行在 http://${host}:${port}/`))
const io = require('socket.io')(server)

const clients = []
let currentPlayer = null

io.on('connection', (client) => {
    // 来人了
    clients.push(client)

    const i = clients.indexOf(client)
    if (i == 0) client.emit('role', '玩家1')
    else if (i == 1) client.emit('role', '玩家2')
    else client.emit('role', '旁观者')

    if (clients.length == 2) {
        currentPlayer = clients[0]
    }

    io.emit('player', clients.length < 2 || currentPlayer != clients[1] ? 'player1' : 'player2')

    // 人走了
    client.on('disconnect', () => {
        const idx = clients.indexOf(client)
        clients.splice(idx, 1)

        clients.forEach((c) => {
            const i = clients.indexOf(c)
            if (i == 0) c.emit('role', '玩家1')
            else if (i == 1) c.emit('role', '玩家2')
            else c.emit('role', '旁观者')
        })

        if (clients.length >= 2) {
            currentPlayer = clients[0]
        } else {
            currentPlayer = null
        }
        io.emit('player', clients.length < 2 || currentPlayer != clients[1] ? 'player1' : 'player2')
    })

    client.on('click', () => {
        if (clients.length >= 2 && client == currentPlayer) {
            // 切换玩家
            if (currentPlayer === clients[0]) {
                currentPlayer = clients[1]
                io.emit('player', 'player2')
            } else {
                currentPlayer = clients[0]
                io.emit('player', 'player1')
            }
        }
    })
})