'use strict'

const {app} = require('electron')
const {EventEmitter} = require('events')
const squirrelUpdate = require('./squirrel-update-win')

class AutoUpdater extends EventEmitter {
  quitAndInstall () {
    if (!this.updateAvailable) {
      return this.emitError('No update available, can\'t quit and install')
    }
    squirrelUpdate.processStart()
    app.quit()
  }

  getFeedURL () {
    return this.updateURL
  }

  setFeedURL (options) {
    let updateURL
    if (typeof options === 'object') {
      if (typeof options.url === 'string') {
        updateURL = options.url
      } else {
        throw new Error('Expected options object to contain a \'url\' string property in setFeedUrl call')
      }
    } else if (typeof options === 'string') {
      updateURL = options
    } else {
      throw new Error('Expected an options object with a \'url\' property to be provided')
    }
    this.updateURL = updateURL
  }

  checkForUpdates () {
    if (!this.updateURL) {
      return this.emitError('Update URL is not set')
    }
    if (!squirrelUpdate.supported()) {
      return this.emitError('Can not find Squirrel')
    }
    this.emit('checking-for-update')
    squirrelUpdate.checkForUpdate(this.updateURL, (error, update) => {
      if (error != null) {
        return this.emitError(error)
      }
      if (update == null) {
        return this.emit('update-not-available')
      }
      this.updateAvailable = true
      this.emit('update-available')
      squirrelUpdate.update(this.updateURL, (error) => {
        if (error != null) {
          return this.emitError(error)
        }
        const {releaseNotes, version} = update
        // Date is not available on Windows, so fake it.
        const date = new Date()
        this.emit('update-downloaded', {}, releaseNotes, version, date, this.updateURL, () => {
          this.quitAndInstall()
        })
      })
    })
  }

  // Private: Emit both error object and message, this is to keep compatibility
  // with Old APIs.
  emitError (message) {
    this.emit('error', new Error(message), message)
  }
}

module.exports = new AutoUpdater()
