module Xcodeproj
  module Helper
    class TargetDiff
      attr_reader :project, :target1, :target2

      def initialize(project, target1_name, target2_name)
        @project = project
        unless @target1 = @project.targets.find { |target| target.name == target1_name }
          raise ArgumentError, "Target 1 by name `#{target1_name}' not found in the project."
        end
        unless @target2 = @project.targets.find { |target| target.name == target2_name }
          raise ArgumentError, "Target 1 by name `#{target2_name}' not found in the project."
        end
      end

      # @return [Array<PBXBuildFile>] A list of source files (that will be
      #         compiled) which are in ‘target 2’ but not in ‘target 1’. The
      #         list is sorted by file path.
      #
      def new_source_build_files
        new = @target2.source_build_phase.files.reject do |target2_build_file|
          @target1.source_build_phase.files.any? do |target1_build_file|
            target1_build_file.file_ref.path == target2_build_file.file_ref.path
          end
        end
        new.sort_by { |build_file| build_file.file_ref.path }
      end
    end
  end
end