require 'mime/types'
require 'open-uri'

module Adparlor
  module Facebook
    module GraphApi
      class AdImage < GraphObject
        include Fields::AdImage
        include Traits::Methods
        field_attrs FIELDS
        allow_method :create, :destroy
        allow_local_method :create, :destroy

        def formatted_image
          return unless @source
          if %r{https?}.match(@source)
            file = open(@source)

            # return nil if we can't open the file from the url
            return nil if file.nil?

            content_type = AdImage.get_content_type(file.content_type, normalized_file_name)
            extension = AdImage.get_preferred_extension(content_type)

            # if content type or extension doesn't exist, the upload will fail on FB side
            return nil if content_type.nil? || extension.nil?

            @source = AdImage.upload_file_with_content_type(normalized_file_name, file, content_type, extension)
          else
            @source = Faraday::UploadIO.new(normalized_file_name, MIME::Types.type_for(normalized_file_name).first.content_type)
          end
        end

        def path
          raise FbError.new('required parameter account_id missing', 500) unless account_id
          if account_id.to_s.include?('act_')
            "/#{account_id}/adimages"
          else
            "/act_#{account_id}/adimages"
          end
        end

        def post(path, options, method = nil)
          raise FbError.new('update not available', 500) if method == 'UPDATE'
          formatted_image
          super path, options
        end

        def update_path
          path
        end

        class << self
          def upload_file_with_content_type(normalized_file_name, file, content_type, extension)
            tmp_file = Tempfile.new([File.basename(normalized_file_name), ".#{extension}"])

            tmp_file.binmode
            tmp_file.write(file.read)
            tmp_file.rewind

            Faraday::UploadIO.new(tmp_file.path, content_type)
          end

          def get_preferred_extension(content_type)
            MIME::Types[content_type].first.preferred_extension
          end

          def get_content_type(header_content_type, file_name)
            content_type = MIME::Types.type_for(file_name)

            return content_type.first.content_type if !file_name.include?('safe_image.php') && !content_type.nil?

            header_content_type.empty? ? nil : header_content_type
          end
        end

        private

        # Remove any query string parameters before getting the mime type
        # should probably be done in mime types gem
        def normalized_file_name
          @source.split('?').first
        end
      end
    end
  end
end