require 'rubygems'
require 'fileutils'
require 'nokogiri'

module Sunspot
  class Installer
    class SolrconfigUpdater
      include TaskHelper

      CONFIG_FILES = %w(solrconfig.xml elevate.xml spellings.txt stopwords.txt synonyms.txt) 

      class <<self
        def execute(solrconfig_path, options = {})
          new(solrconfig_path, options).execute
        end
      end

      def initialize(solrconfig_path, options)
        @force = !!options[:force]
        unless @force || File.exist?(solrconfig_path)
          abort("#{File.expand_path(@solrconfig_path)} doesn't exist." +
                " Are you sure you're pointing to a SOLR_HOME?")
        end
        @solrconfig_path = solrconfig_path
        @verbose = !!options[:verbose]
      end

      def execute
        if @force
          config_dir = File.dirname(@solrconfig_path)
          FileUtils.mkdir_p(config_dir)
          CONFIG_FILES.each do |file|
            source_path =
              File.join(File.dirname(__FILE__), '..', '..', '..', 'solr', 'solr', 'conf', file)
            FileUtils.cp(source_path, config_dir)
            say("Copied default #{file} to #{config_dir}")
          end
        else
          @document = File.open(@solrconfig_path) do |f|
            Nokogiri::XML(
              f, nil, nil, 
              Nokogiri::XML::ParseOptions::DEFAULT_XML |
              Nokogiri::XML::ParseOptions::NOBLANKS
            )
          end
          @root = @document.root
          maybe_create_spatial_component
          maybe_add_spatial_component_to_standard_handler
          original_path = "#{@solrconfig_path}.orig"
          FileUtils.cp(@solrconfig_path, original_path)
          say("Saved backup of original to #{original_path}")
          File.open(@solrconfig_path, 'w') do |file|
            @document.write_to(
              file,
              :indent => 2
            )
          end
          say("Wrote solrconfig to #{@solrconfig_path}")
        end
      end

      private

      def maybe_create_spatial_component
        if @root.xpath('searchComponent[@name="spatial"]').any?
          say('Spatial search component already defined')
        else
          say('Defining spatial search component')
          search_component_node =
            Nokogiri::XML::Node.new('searchComponent', @document)
          search_component_node['name'] = 'spatial'
          search_component_node['class'] =
            'me.outofti.solrspatiallight.SpatialQueryComponent'
          @root << search_component_node
        end
      end

      def maybe_add_spatial_component_to_standard_handler
        standard_handler_node =
          @root.xpath('requestHandler[@name="standard"]').first
        last_components_node =
          standard_handler_node.xpath('arr[@name="last-components"]').first ||
          add_element(standard_handler_node, 'arr', 'name' => 'last-components')
        if last_components_node.xpath('str[normalize-space()="spatial"]').any?
          say('Spatial search component already in standard search handler')
        else
          say('Adding spatial search component into standard search handler')
          add_element(last_components_node, 'str').content = 'spatial'
        end
      end
    end
  end
end