# Copyright (C) 2012-2016 Zammad Foundation, http://zammad-foundation.org/

class UserDevice < ApplicationModel
  store     :device_details
  store     :location_details
  validates :name, presence: true

  belongs_to :user

  before_create  :fingerprint_validation
  before_update  :fingerprint_validation

  association_attributes_ignored :user

=begin

store new device for user if device not already known

  user_device = UserDevice.add(
    'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.107 Safari/537.36',
    '172.0.0.1',
    user.id,
    'fingerprintABC123',
    'session', # session|basic_auth|token_auth|sso
  )

=end

  def self.add(user_agent, ip, user_id, fingerprint, type)

    if user_agent.blank?
      user_agent = 'unknown'
    end

    # get location info
    location_details = Service::GeoIp.location(ip)
    location = 'unknown'
    if location_details && location_details['country_name']
      location = location_details['country_name']
    end

    # find device by fingerprint
    device_exists_by_fingerprint = false
    if fingerprint.present?
      UserDevice.fingerprint_validation(fingerprint)
      user_devices = UserDevice.where(
        user_id:     user_id,
        fingerprint: fingerprint,
      )
      user_devices.each do |local_user_device|
        device_exists_by_fingerprint = true
        next if local_user_device.location != location
        return action(local_user_device.id, user_agent, ip, user_id, type) if local_user_device
      end
    end

    # for basic_auth|token_auth search for user agent
    device_exists_by_user_agent = false
    if %w[basic_auth token_auth].include?(type)
      user_devices = UserDevice.where(
        user_id:    user_id,
        user_agent: user_agent,
      )
      user_devices.each do |local_user_device|
        device_exists_by_user_agent = true
        next if local_user_device.location != location
        return action(local_user_device.id, user_agent, ip, user_id, type) if local_user_device
      end
    end

    # get browser details
    browser = {}
    if user_agent != 'unknown'
      browser = Browser.new(user_agent, accept_language: 'en-us')
      browser = {
        plattform:    browser.platform.to_s.camelize,
        name:         browser.name,
        version:      browser.version,
        full_version: browser.full_version,
      }
    end

    # generate device name
    if browser[:name] == 'Generic Browser'
      browser[:name] = user_agent
    end
    name = ''
    if browser[:plattform].present? && browser[:plattform] != 'Other'
      name = browser[:plattform]
    end
    if browser[:name].present? && browser[:name] != 'Other'
      if name.present?
        name += ', '
      end
      name += browser[:name]
    end

    # if not identified, use user agent
    if name.blank? || name == 'Other, Other' || name == 'Other'
      name = user_agent
      browser[:name] = user_agent
    end

    # check if exists
    user_device = find_by(
      user_id:     user_id,
      os:          browser[:plattform],
      browser:     browser[:name],
      location:    location,
      fingerprint: fingerprint,
    )

    if user_device
      return action(user_device.id, user_agent, ip, user_id, type) if user_device
    end

    # create new device
    user_device = create!(
      user_id:          user_id,
      name:             name,
      os:               browser[:plattform],
      browser:          browser[:name],
      location:         location,
      device_details:   browser,
      location_details: location_details,
      user_agent:       user_agent,
      ip:               ip,
      fingerprint:      fingerprint,
    )

    # send notification if needed
    user_devices = UserDevice.where(user_id: user_id).count
    if user_devices >= 2

      # notify on now device of if country has changed
      if device_exists_by_fingerprint || device_exists_by_user_agent
        user_device.notification_send('user_device_new_location')
      else
        user_device.notification_send('user_device_new')
      end
    end

    user_device
  end

=begin

log user device action

  UserDevice.action(
    user_device_id,
    'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.107 Safari/537.36',
    '172.0.0.1',
    user.id,
    'session', # session|basic_auth|token_auth|sso
  )

=end

  def self.action(user_device_id, user_agent, ip, user_id, type)
    user_device = UserDevice.lookup(id: user_device_id)

    # update location if needed
    if user_device.ip != ip
      user_device.ip = ip
      location_details = Service::GeoIp.location(ip)

      # if we do not have any data from backend (e.g. geo ip is out of service), ignore log
      if location_details && location_details['country_name']

        user_device.location_details = location_details
        location = location_details['country_name']

        # notify if country has changed
        if user_device.location != location
          return UserDevice.add(
            user_agent,
            ip,
            user_id,
            user_device.fingerprint,
            type,
          )
        end
      end
    end

    # only update updated_at every 5 min.
    return user_device if type != 'session' && (user_device.updated_at + 5.minutes) > Time.zone.now

    # update attributes
    user_device.updated_at = Time.zone.now # force update, also if no other attribute has changed
    user_device.save!
    user_device
  end

=begin

send user notification about new device or new location for device

  user_device = UserDevice.find(id)

  user_device.notification_send('user_device_new_location')

=end

  def notification_send(template)
    user = User.find(user_id)

    if user.email.blank?
      Rails.logger.info { "Unable to notification (#{template}) to user_id: #{user.id} be cause of missing email address." }
      return false
    end

    Rails.logger.debug { "Send notification (#{template}) to: #{user.email}" }

    NotificationFactory::Mailer.notification(
      template: template,
      user:     user,
      objects:  {
        user_device: self,
        user:        user,
      }
    )

    true
  end

=begin

delete device devices of user

  user_devices = UserDevice.remove(user.id)

=end

  def self.remove(user_id)
    UserDevice.where(user_id: user_id).destroy_all
  end

=begin

check fingerprint string

  UserDevice.fingerprint_validation(fingerprint)

=end

  def self.fingerprint_validation(fingerprint)
    return true if fingerprint.blank?
    raise Exceptions::UnprocessableEntity, "fingerprint is #{fingerprint.to_s.length} chars but can only be 160 chars!" if fingerprint.to_s.length > 160

    true
  end

  private

  def fingerprint_validation
    UserDevice.fingerprint_validation(fingerprint)
  end
end