require "builder"

module RailsConnector
  module SES
    class VerityAccessor
      require "net/http"
      require "uri"
      require "rexml/document"

      #--
      # Options: see VeritySearchRequest
      #++
      def initialize(query, options = {})
        @query = query
        @options = {
          host: "localhost",
          port: 3011,
          offset: 0,
          limit: 10,
          min_relevance: 50,
          max_docs: "unlimited",
          parser: "simple",
          sort_order: [%w(score desc), %w(name asc)],
          collections: ["cm-contents"],
          base_query: nil
        }.merge(options)
        @options[:collections] = Array(options[:collection]).flatten if options.has_key?(:collection)
      end

      # Queries the SES and returns a SearchResult.
      #
      # Exceptions:
      # * SearchError - SES reported an error.
      #
      def search
        parse_response_payload(send_to_ses(build_request_payload))
      end

      private

      def build_request_payload
        x = Builder::XmlMarkup.new
        x.instruct!
        x.tag!("ses-payload", "payload-id" => "d-1f6a64dec16aa328-00000020-i", "timestamp" => Time.now.to_iso, "version" => "6") do
          x.tag!("ses-header") do
            x.tag!("ses-sender", "sender-id" => "42", "name" => "infopark-rails-connector")
          end
          x.tag!("ses-request", "request-id" => "d-1f6a64dec16aa328-00000021-j-1", "preclusive" => "false") do
            x.tag!("ses-search") do
              x.query @query, parser: @options[:parser]
              x.resultRecord do
                x.resultField "objId"
                x.resultField "score"
              end
              x.offset do
                x.start @options[:offset].to_i + 1
                x.length @options[:limit]
              end
              x.minRelevance @options[:min_relevance]
              x.maxDocs @options[:max_docs]

              unless @options[:sort_order].blank?
                x.sortOrder do
                  @options[:sort_order].each do |attribute, direction|
                    x.sortField attribute, direction: direction
                  end
                end
              end

              x.searchBase do
                @options[:collections].each { |item| x.collection item }
                x.query @options[:base_query], parser: @options[:parser] if @options[:base_query]
              end
            end
          end
        end
      end

      def send_to_ses(payload)
        res = Net::HTTP.new(@options[:host], @options[:port].to_i).start do |http|
          req = Net::HTTP::Post.new("/xml")
          req.body = payload
          http.request(req)
        end
        res.body
      end

      def parse_response_payload(response)
        xml = REXML::Document.new(response)
        if xml.elements["/ses-payload/ses-response/ses-code"].attributes["numeric"] == "200"
          build_successful_result(xml)
        else
          handle_error(xml)
        end
      end

      def build_successful_result(response)
        result = SearchResult.new(response.elements["/ses-payload/ses-response/ses-code/searchResults"].attributes["hits"].to_i)
        response.elements.to_a("/ses-payload/ses-response/ses-code/searchResults/record").each do |record|
          hit = Hit.new(record.elements["objId"].text.to_i, record.elements["score"].text.to_f)
          if hit.obj.present?
            result << hit
          else
            Rails.logger.warn("OBJ with ID ##{record.elements["objId"].text.to_i} not found: This search result will not be shown")
          end
        end
        result
      end

      # SES raises these errors:
      # 100171: ERROR_SYSTEM_SES_INTERNALVERITYERROR_DS
      # 100230: ERROR_SYSTEM_SES_VERITYERROR_DS
      # 100099: ERROR_SYSTEM_SES_DUPLICATECOLLETION_S
      # 100173: ERROR_SYSTEM_SES_OPENCOLLECTIONFAILED
      # 100103: ERROR_SYSTEM_SEARCHENGINE_SESSIONNEWFAILED
      # 100177: ERROR_SYSTEM_SEARCHENGINE_BULKSUBMITFAILED
      def handle_error(response)
        msg = ""
        response.elements.each("/ses-payload/ses-response/ses-code/errorStack/error") do |error|
          msg << error.elements["phrase"].text
          msg << "\n"
        end
        raise SearchError, msg
      end
    end
  end
end