import express from 'express'
import { WebSocketServer } from 'ws'

import * as pty from 'node-pty'

const app = express()

app.use(express.json())

app.get('/api/foo', c => c.json({ foo: 42 }))

app.get('/api/docker/:tag', (req, res) => {
    wss.handleUpgrade(req, res.socket, req.headers, ws => {
        wss.emit('connection', ws, req)
    })
})

const server = app.listen(5432, () => {
    console.log('Starting API server on :5432...')
})

const wss = new WebSocketServer({ server })

wss.on('connection', (ws, req) => {
    const url = new URL(req.url, `http://${req.headers.host}`)
    const tag = url.pathname.split('/')[3]

    console.log(`Client connected, initializing "${tag}"...`)

    const docker = pty.spawn('docker', ['run', '--init', '-it', '--rm', tag, '/bin/sh'])

    docker.onExit(e => {
        ws.send(JSON.stringify(e))
        ws.close()
        console.log('Client requested stop')
    })

    docker.onData(data => {
        ws.send(data)
    })

    ws.on('message', message => {
        docker.write(message)
    })

    ws.on('close', () => {
        docker.kill()
        console.log('Client disconnected')
    })
})