var mongoose = require('mongoose')
var findOrCreate = require('mongoose-findorcreate')
var _ = require('lodash')
var db, PushToken, Notification, Channel

mongoose.Promise = require('bluebird')

function init (config) {
  db = mongoose.connect(config.mongodbUrl)
  mongoose.connection.on('error', errorHandler)

  var pushTokenSchema = new db.Schema({
    platform: {
      type: 'String',
      required: true,
      lowercase: true,
      enum: ['ios', 'android'],
    },
    token: {
      type: 'String',
      required: true,
      unique: true,
    },
    channel: {
      type: 'String',
      required: true,
    },
  })

  var channelSchema = new db.Schema({
    channel: {
      type: 'String',
      required: true,
      lowercase: true,
    },
    last_push: {
      type: 'Date',
      required: true,
    }
  })
  channelSchema.plugin(findOrCreate);

  var notificationSchema = new db.Schema({
    channel: {
      type: 'String',
      required: true,
      lowercase: true,
    },
    date: {
      type: 'Date',
      required: true,
    }
  })

  module.exports.PushToken = PushToken = db.model('PushToken', pushTokenSchema)
  module.exports.Notification = Notification = db.model('Notification', notificationSchema)
  module.exports.Channel = Channel = db.model('Channel', channelSchema)
}

function errorHandler (error) {
  console.error('ERROR: ' + error)
}

/* devices / tokens */

function addToken (data) {
  return new PushToken(data).save()
}
function getAllIOSTokens (channel, cb) {
  PushToken.distinct("token", { channel: channel, platform: 'ios' }, function (err, tokens) {
    if (err) return cb(err, [])
    return cb(null, tokens)
  })
}
function getAllAndroidTokens (channel, cb) {
  PushToken.distinct("token", { channel: channel, platform: 'android' }, function (err, tokens) {
    if (err) return cb(err, [])
    return cb(null, tokens)
  })
}
function getAllTokens (channel, cb) {
  PushToken.find({ channel: channel }, function (err, items) {
    if (err) return cb(err, [])
    var items = items.map(function (item) {
      return { platform: item.get('platform'), token: item.get('token') }
    })
    return cb(null, items)
  })
}
function removeToken (data) {
  PushToken.find(data).remove().exec()
}
function getDeviceCount (channels, cb) {
  var countz = {}
  get_next()
  function get_next() {
    var channel = channels.pop()
    PushToken.distinct("token", { channel: channel }, function(err, tokens){
      countz[channel] = tokens.length
      if (channels.length) {
        return get_next()
      }
      else {
        cb(countz)
      }
    })
  }
}

/* notifications */

function addNotification (channel, cb) {
  var now = new Date
  Channel.findOrCreate({channel: channel}, {last_push: now}, function(err, note, created) {
    if (err) {
      console.error("Error finding/creating notification", err)
      cb(err, false)
      return
    }
    else if (! created) {
      note.last_push = now
      note.save()
    }
    cb(null, note)
  })
  new Notification ({
    channel: channel,
    date: now,
  }).save()
}

function getNotifications (cb) {
  Notification.find(function (err, items) {
    if (err) return cb(err, null)

    var items = _.map(items, function (item) {
      return _.pick(item, ['channel', 'last_push'])
    })

    return cb(null, items)
  })
}

/* wrap functions for some reason */

module.exports = {
  init: init,
  addToken: addToken,
  removeToken: removeToken,
  getAllTokens: getAllTokens,
  getAllIOSTokens: getAllIOSTokens,
  getAllAndroidTokens: getAllAndroidTokens,
  getDeviceCount: getDeviceCount,
  addNotification: addNotification,
  getNotifications: getNotifications,
}