'use strict'

// helper to start and stop the redis process.
var config = require('./config')
var fs = require('fs')
var path = require('path')
var spawn = require('win-spawn')
var tcpPortUsed = require('tcp-port-used')
var bluebird = require('bluebird')

// wait for redis to be listening in
// all three modes (ipv4, ipv6, socket).
function waitForRedis (available, cb, port) {
  if (process.platform === 'win32') return cb()

  var time = Date.now()
  var running = false
  var socket = '/tmp/redis.sock'
  if (port) {
    // We have to distinguish the redis sockets if we have more than a single redis instance running
    socket = '/tmp/redis' + port + '.sock'
  }
  port = port || config.PORT
  var id = setInterval(function () {
    if (running) return
    running = true
    bluebird.join(
      tcpPortUsed.check(port, '127.0.0.1'),
      tcpPortUsed.check(port, '::1'),
      function (ipV4, ipV6) {
        if (ipV6 === available && ipV4 === available) {
          if (fs.existsSync(socket) === available) {
            clearInterval(id)
            return cb()
          }
          // The same message applies for can't stop but we ignore that case
          throw new Error('Port ' + port + ' is already in use. Tests can\'t start.\n')
        }
        if (Date.now() - time > 6000) {
          throw new Error('Redis could not start on port ' + (port || config.PORT) + '\n')
        }
        running = false
      }).catch(function (err) {
        console.error('\x1b[31m' + err.stack + '\x1b[0m\n')
        process.exit(1)
      })
  }, 100)
}

module.exports = {
  start: function (done, conf, port) {
    var spawnFailed = false
    // spawn redis with our testing configuration.
    var confFile = conf || path.resolve(__dirname, '../conf/redis.conf')
    var rp = spawn('redis-server', [confFile], {})

    // capture a failure booting redis, and give
    // the user running the test some directions.
    rp.once('exit', function (code) {
      if (code !== 0) spawnFailed = true
    })

    // wait for redis to become available, by
    // checking the port we bind on.
    waitForRedis(true, function () {
      // return an object that can be used in
      // an after() block to shutdown redis.
      return done(null, {
        spawnFailed: function () {
          return spawnFailed
        },
        stop: function (done) {
          if (spawnFailed) return done()
          rp.once('exit', function (code) {
            var error = null
            if (code !== null && code !== 0) {
              error = new Error('Redis shutdown failed with code ' + code)
            }
            waitForRedis(false, function () {
              return done(error)
            }, port)
          })
          rp.kill('SIGTERM')
        }
      })
    }, port)
  }
}