module Bot
  class Responder
    include ActionView::Helpers::TextHelper
    include ActionView::Helpers::DateHelper

    class_attribute :respond_to_types

    attr_reader :message, :user, :responses, :handler

    def self.respond_to(*types)
      new_types = (respond_to_types || []).dup
      types.each { |type| new_types << type.to_s }.uniq
      self.respond_to_types = new_types.freeze
    end

    def initialize(message, user, responses, handler)
      @message = message
      @user = user
      @responses = responses
      @handler = handler
    end

    def can_respond_to_type?(type)
      valid_message_types = self.class.respond_to_types || ['text']
      valid_message_types.include?(type)
    end

    def can_handle?
      !responses.count
    end

    def handle
      raise NotImplementedError
    end

  protected

    def text_response(message_text, suggested_responses=false)
      text_response = {
        'type'  => 'text',
        'to'    => message['from'],
        'body'  => message_text,
        'typeTime' => 0
      }
      text_response['suggestedResponses'] = suggested_responses if suggested_responses
      text_response
    end

    def photo_response(photo_url, suggested_responses=false)
      photo_response = {
        'type'  => 'gallery',
        'to'    => message['from'],
        'picUrl' => photo_url
      }
      photo_response['suggestedResponses'] = suggested_responses if suggested_responses
      photo_response
    end

    def video_response(video_id, suggested_responses=false)
      video_response = {
        'type'     => 'video',
        'to'       => message['from'],
        'videoId' => video_id,
        'muted' => true,
        'autoplay' => true
      }
      video_response['suggestedResponses'] = suggested_responses if suggested_responses
      video_response
    end

    def delay(message, delay)
      message['delay'] = delay
      message
    end

    def match_message(match)
      if match.is_a?(Regexp)
        !!(message['body'] =~ match)
      else
        message['body'].upcase == match.upcase
      end
    end

    def no_responses?
      responses.empty?
    end

    def reexecute_with(current_response, new_message=false)
      handler.execute_chain(new_message || message, Array.wrap(current_response), user)
    end

    def scan_data
      JSON.parse(message['data'])
    end
  end
end