# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/

class Sequencer
  class Unit
    module Import
      module Kayako
        module SubSequence
          class Generic < Sequencer::Unit::Base

            uses :dry_run, :import_job, :field_map, :id_map, :default_language

            attr_accessor :iteration, :result

            EXPECTING = %i[action response].freeze

            def process
              loop.each_with_index do |_, iteration|
                @iteration = iteration
                @result = ::Sequencer.process(sequence_name,
                                              parameters: sequence_params,
                                              expecting:  self.class.const_get(:EXPECTING))
                break if iteration_should_stop?
              end
            end

            def sequence_params
              {
                request_params:   request_params,
                import_job:       import_job,
                dry_run:          dry_run,
                object:           object,
                default_language: default_language,
                field_map:        field_map,
                id_map:           id_map,
              }
            end

            def request_params
              return {} if iteration.zero?

              if cursor_pagination?
                return cursor_pagination
              end

              offset_pagination
            end

            def object
              @object ||= self.class.name.demodulize.singularize
            end

            def sequence_name
              raise NotImplementedError
            end

            private

            def offset_pagination
              {
                offset: offset,
              }
            end

            def offset
              iteration * 5 # TODO: only ddebug, normally 100
            end

            def cursor_pagination?
              return if result.nil?

              @cursor_pagination ||= result[:response].header['link'].include?('after_id')
            end

            def cursor_pagination
              {
                after_id: cursor_after_id
              }
            end

            def cursor_after_id
              unescaped_header_next_link.match(%r{after_id=(\d+)})[1]
            end

            def unescaped_header_next_link
              CGI.unescape(CGI.unescape(result[:response].header['link']))
            end

            def iteration_should_stop?
              return true if result[:action] == :failed
              return true if result[:response].header['link'].blank? || result[:response].header['link'].exclude?('rel="next"')

              false
            end
          end
        end
      end
    end
  end
end