# -*- coding: utf-8 -*-
require 'write_xlsx/package/xml_writer_simple'
require 'write_xlsx/utility'

module Writexlsx
  module Package
    class Relationships

      include Writexlsx::Utility

      Schema_root     = 'http://schemas.openxmlformats.org'
      Package_schema  = Schema_root + '/package/2006/relationships'
      Document_schema = Schema_root + '/officeDocument/2006/relationships'

      def initialize
        @writer = Package::XMLWriterSimple.new
        @rels   = []
        @id     = 1
      end

      def set_xml_writer(filename)
        @writer.set_xml_writer(filename)
      end

      def assemble_xml_file
        write_xml_declaration
        write_relationships
        @writer.crlf
        @writer.close
      end

      #
      # Add container relationship to XLSX .rels xml files.
      #
      def add_document_relationship(type, target)
        type   = Document_schema + type
        target = target

        @rels.push([type, target])
      end

      #
      # Add container relationship to XLSX .rels xml files.
      #
      def add_package_relationship(type, target)
        type   = Package_schema + type
        target = target + '.xml'

        @rels.push([type, target])
      end

      #
      # Add worksheet relationship to sheet.rels xml files.
      #
      def add_worksheet_relationship(type, target, target_mode = nil)
        type   = Document_schema + type
        target = target

        @rels.push([type, target, target_mode])
      end

      private

      def write_xml_declaration
        @writer.xml_decl
      end

      #
      # Write the <Relationships> element.
      #
      def write_relationships
        attributes = ['xmlns', Package_schema]

        @writer.tag_elements('Relationships', attributes) do
          @rels.each { |rel| write_relationship(*rel) }
        end
      end

      #
      # Write the <Relationship> element.
      #
      def write_relationship(type, target, target_mode = nil)
        attributes = [
          'Id',     "rId#{@id}",
          'Type',   type,
          'Target', target
        ]
        @id += 1

        attributes << 'TargetMode' << target_mode if target_mode

        @writer.empty_tag('Relationship', attributes)
      end
    end
  end
end