peertube/lib/friends.js

'use strict'

var async = require('async')
var config = require('config')
var fs = require('fs')
var request = require('request')

var constants = require('../initializers/constants')
var logger = require('../helpers/logger')
var peertubeCrypto = require('../helpers/peertubeCrypto')
var Pods = require('../models/pods')
var poolRequests = require('../lib/poolRequests')
var requests = require('../helpers/requests')
var Videos = require('../models/videos')

var http = config.get('webserver.https') ? 'https' : 'http'
var host = config.get('webserver.host')
var port = config.get('webserver.port')

var pods = {
  addVideoToFriends: addVideoToFriends,
  hasFriends: hasFriends,
  makeFriends: makeFriends,
  quitFriends: quitFriends,
  removeVideoToFriends: removeVideoToFriends
}

function addVideoToFriends (video) {
  // To avoid duplicates
  var id = video.name + video.magnetUri
  // ensure namePath is null
  video.namePath = null
  poolRequests.addRequest(id, 'add', video)
}

function hasFriends (callback) {
  Pods.count(function (err, count) {
    if (err) return callback(err)

    var has_friends = (count !== 0)
    callback(null, has_friends)
  })
}

function makeFriends (callback) {
  var pods_score = {}

  logger.info('Make friends!')
  fs.readFile(peertubeCrypto.getCertDir() + 'peertube.pub', 'utf8', function (err, cert) {
    if (err) {
      logger.error('Cannot read public cert.')
      return callback(err)
    }

    var urls = config.get('network.friends')

    async.each(urls, computeForeignPodsList, function (err) {
      if (err) return callback(err)

      logger.debug('Pods scores computed.', { pods_score: pods_score })
      var pods_list = computeWinningPods(urls, pods_score)
      logger.debug('Pods that we keep computed.', { pods_to_keep: pods_list })

      makeRequestsToWinningPods(cert, pods_list)
    })
  })

  // -----------------------------------------------------------------------

  function computeForeignPodsList (url, callback) {
    // Let's give 1 point to the pod we ask the friends list
    pods_score[url] = 1

    getForeignPodsList(url, function (err, foreign_pods_list) {
      if (err) return callback(err)
      if (foreign_pods_list.length === 0) return callback()

      async.each(foreign_pods_list, function (foreign_pod, callback_each) {
        var foreign_url = foreign_pod.url

        if (pods_score[foreign_url]) pods_score[foreign_url]++
        else pods_score[foreign_url] = 1

        callback_each()
      }, function () {
        callback()
      })
    })
  }

  function computeWinningPods (urls, pods_score) {
    // Build the list of pods to add
    // Only add a pod if it exists in more than a half base pods
    var pods_list = []
    var base_score = urls.length / 2
    Object.keys(pods_score).forEach(function (pod) {
      if (pods_score[pod] > base_score) pods_list.push({ url: pod })
    })

    return pods_list
  }

  function makeRequestsToWinningPods (cert, pods_list) {
    // Stop pool requests
    poolRequests.deactivate()
    // Flush pool requests
    poolRequests.forceSend()

    // Get the list of our videos to send to our new friends
    Videos.listOwned(function (err, videos_list) {
      if (err) {
        logger.error('Cannot get the list of videos we own.')
        return callback(err)
      }

      var data = {
        url: http + '://' + host + ':' + port,
        publicKey: cert,
        videos: videos_list
      }

      requests.makeMultipleRetryRequest(
        { method: 'POST', path: '/api/' + constants.API_VERSION + '/pods/', data: data },

        pods_list,

        function eachRequest (err, response, body, url, pod, callback_each_request) {
          // We add the pod if it responded correctly with its public certificate
          if (!err && response.statusCode === 200) {
            Pods.add({ url: pod.url, publicKey: body.cert, score: constants.FRIEND_BASE_SCORE }, function (err) {
              if (err) logger.error('Error with adding %s pod.', pod.url, { error: err })

              Videos.addRemotes(body.videos, function (err) {
                if (err) logger.error('Error with adding videos of pod.', pod.url, { error: err })

                logger.debug('Adding remote videos from %s.', pod.url, { videos: body.videos })
                return callback_each_request()
              })
            })
          } else {
            logger.error('Error with adding %s pod.', pod.url, { error: err || new Error('Status not 200') })
            return callback_each_request()
          }
        },

        function endRequests (err) {
          // Now we made new friends, we can re activate the pool of requests
          poolRequests.activate()

          if (err) {
            logger.error('There was some errors when we wanted to make friends.')
            return callback(err)
          }

          logger.debug('makeRequestsToWinningPods finished.')
          return callback(null)
        }
      )
    })
  }
}

function quitFriends (callback) {
  // Stop pool requests
  poolRequests.deactivate()
  // Flush pool requests
  poolRequests.forceSend()

  Pods.list(function (err, pods) {
    if (err) return callback(err)

    var request = {
      method: 'POST',
      path: '/api/' + constants.API_VERSION + '/pods/remove',
      sign: true,
      encrypt: true,
      data: {
        url: 'me' // Fake data
      }
    }

    // Announce we quit them
    requests.makeMultipleRetryRequest(request, pods, function () {
      Pods.removeAll(function (err) {
        poolRequests.activate()

        if (err) return callback(err)

        logger.info('Broke friends, so sad :(')

        Videos.removeAllRemotes(function (err) {
          if (err) return callback(err)

          logger.info('Removed all remote videos.')
          callback(null)
        })
      })
    })
  })
}

function removeVideoToFriends (video) {
  // To avoid duplicates
  var id = video.name + video.magnetUri
  poolRequests.addRequest(id, 'remove', video)
}

// ---------------------------------------------------------------------------

module.exports = pods

// ---------------------------------------------------------------------------

function getForeignPodsList (url, callback) {
  var path = '/api/' + constants.API_VERSION + '/pods'

  request.get(url + path, function (err, response, body) {
    if (err) return callback(err)

    callback(null, JSON.parse(body))
  })
}