# Copyright (c) 2020 Jerome Arbez-Gindre
# frozen_string_literal: true

require('csv')
require('defmastership/export/body_formatter')
require('defmastership/export/header_formatter')

module Defmastership
  # Module to host export classes
  module Export
    # Module to host CSV export classes
    module CSV
      # to export a CSV file
      class Formatter
        # @param doc [Document] the document to export
        # @param sep [String] the CSV separator
        def initialize(doc, sep)
          @doc = doc
          @sep = sep
        end

        # Export the document to a CSV file
        #
        # @param output_file [Strinf] filename for the export
        def export_to(output_file)
          column_list = build_column_list
          ::CSV.open(output_file, 'w:ISO-8859-1', col_sep: @sep) do |csv|
            csv << header(column_list)
            export_definitions_in(csv, column_list)
          end
        end

        private

        def export_definitions_in(csv, column_list)
          @doc.definitions.each { |definition| csv << body(definition, column_list) }
        end

        def header(column_list)
          header_formatter = HeaderFormatter.new(@doc)
          header_line = column_list.map { |part| header_formatter.public_send(part) }
          header_line.flatten
        end

        def body(definition, column_list)
          body_formatter = BodyFormatter.new(@doc, definition)
          body_line = column_list.map { |part| body_formatter.public_send(part) }
          body_line.flatten
        end

        def build_column_list
          [
            [:wrong_explicit_checksum, @doc.wrong_explicit_checksum?],
            [:explicit_version, @doc.explicit_version?],
            [:labels, !@doc.labels.empty?],
            [:eref, !@doc.eref.empty?],
            [:iref, @doc.iref],
            [:attributes, !@doc.attributes.empty?]
          ].reduce([:fixed]) { |acc, elem| acc + (elem.fetch(1) ? [elem.first] : []) }
        end
      end
    end
  end
end