# frozen_string_literal: true

module Assembly
  class ContentMetadata
    # Builds a groups of related Files, based on bundle
    class FileSetBuilder
      def self.build(bundle:, objects:, style:)
        new(bundle: bundle, objects: objects, style: style).build
      end

      def initialize(bundle:, objects:, style:)
        @bundle = bundle
        @objects = objects
        @style = style
      end

      # @return [Array<FileSet>] a list of filesets in the object
      def build
        case bundle
        when :default # one resource per object
          objects.collect { |obj| FileSet.new(resource_files: [obj], style: style) }
        when :filename # one resource per distinct filename (excluding extension)
          build_for_filename
        when :dpg # group by DPG filename
          build_for_dpg
        when :prebundled
          # if the user specifies this method, they will pass in an array of arrays, indicating resources, so we don't need to bundle in the gem
          objects.map { |inner| FileSet.new(resource_files: inner, style: style) }
        else
          raise 'Invalid bundle method'
        end
      end

      private

      attr_reader :bundle, :objects, :style

      def build_for_filename
        # loop over distinct filenames, this determines how many resources we will have and
        # create one resource node per distinct filename, collecting the relevant objects with the distinct filename into that resource
        distinct_filenames = objects.collect(&:filename_without_ext).uniq # find all the unique filenames in the set of objects, leaving off extensions and base paths
        distinct_filenames.map do |distinct_filename|
          FileSet.new(resource_files: objects.collect { |obj| obj if obj.filename_without_ext == distinct_filename }.compact,
                      style: style)
        end
      end

      def build_for_dpg
        # loop over distinct dpg base names, this determines how many resources we will have and
        # create one resource node per distinct dpg base name, collecting the relevant objects with the distinct names into that resource

        distinct_filenames = objects.collect(&:dpg_basename).uniq # find all the unique DPG filenames in the set of objects
        resources = distinct_filenames.map do |distinct_filename|
          FileSet.new(dpg: true, resource_files: objects.collect { |obj| obj if obj.dpg_basename == distinct_filename && !ContentMetadata.special_dpg_folder?(obj.dpg_folder) }.compact, style: style)
        end
        objects.each { |obj| resources << FileSet.new(dpg: true, resource_files: [obj], style: style) if ContentMetadata.special_dpg_folder?(obj.dpg_folder) } # certain subfolders require individual resources for files within them regardless of file-naming convention
        resources
      end
    end
  end
end