#!/usr/bin/env node

const tls = require('tls')
const execFile = require('child_process').execFile

const args = process.argv;
const user = args[2] || process.env.GMAIL_NOTIFY_USER
const pass = args[3] || process.env.GMAIL_NOTIFY_PASS
const cmd  = args[4] || process.env.GMAIL_NOTIFY_CMD

function usage() {
  console.error("usage: gmail-notify [user] [pass] [cmd]")
  process.exit(1)
}

if (!user || !pass || !cmd) {
  usage();
}

console.error(`using ${user} ${pass} ${cmd}`)

const socket = tls.connect({host: "imap.gmail.com", port: 993}, () => {
  function handleNotifications() {
    socket.on("data", (data) => {
      var str = data.toString();
      console.error(str)

      const res = /\* (\d+) EXISTS/.exec(str);
      if (res && res[1]) {
        execFile(cmd, [res[1]])
      }
    })
  }

  socket.write(`tag login ${user} ${pass}\r\n`)
  socket.write("A001 SELECT INBOX\r\n")
  socket.write("A002 IDLE\r\n")

  handleNotifications()

  socket.on("close", () => process.exit(2))

  setInterval(socket.write.bind(null, "A002 IDLE\r\n"), 300000)
})