require "fiona7/search_engine"
require "rails_connector/verity_search_request"
require "fiona7/custom_verity_accessor"

require "fiona7/attribute_names_from_queries"
require "fiona7/attribute_names_from_cms"

module Fiona7
  class VeritySearchEngine < SearchEngine
    def initialize(*args)
      super
      # scrivito sdk likes to send a query with limit 0
      # just to fetch the total count of results
      # but verity does not like limit 0 very much
      if @limit == 0
        @limit = 1
      end
    end

    def results
      @results || fetch_results
    end

    def objects
      return @objects if @objects

      @results || fetch_results
      fetch_objects
    end

    protected
    def construct_search_request
      # TODO: sort order!
      options = {}
      options[:sort_order] = [["score", "desc"], ["lastChanged", "desc"]]
      options[:limit] = @limit.to_i if @limit
      options[:offset] = @offset.to_i if @offset.to_i > 0
      VeritySearchRequest.new(@query, options, @klass == Fiona7::ReleasedObj)
    end

    def fetch_results
      @search_request = construct_search_request
      @search_response = @search_request.fetch_hits
      @count = @search_response.total_hits
      @results = @search_response.map(&:id)
    end

    def fetch_objects
      unordered_objects = @klass.where(obj_id: @results.map(&:id)).to_a
      ordered_objects = @results.map {|r| unordered_objects.find {|o| o.id.to_i == r.id } }.compact
    end

    class VeritySearchRequest < ::RailsConnector::VeritySearchRequest
      def initialize(query, options={}, use_released=false)
        @query = query
        @query_string = build_query_string(query)
        Rails.logger.debug "VERITY QUERY:\n#{@query_string}"
        @options = default_search_options.merge(options)
        @use_released ||= use_released
      end

      def fetch_hits
        Fiona7::CustomVerityAccessor.new(@query_string, {:base_query => base_query}.merge(@options)).search
      end

      protected

      class << self
        attr_accessor :configured_host, :configured_port
      end

      def default_search_options
        {
          :host => self.class.configured_host,
          :port => self.class.configured_port,
          :collection => 'cm-contents'
        }
      end

      def build_query_string(query)
        query = normalize_query(query)
        complex_query_string(query)
      end

      def complex_query_string(query)
        conditions = query.map do |q|
          field = resolve_field_name(q[:field])

          # paths are sadly not in the search index by default.
          next if field == :visiblePath

          case q[:operator]
          when :equal
            if field == :__dummy__
              '("edited" <#IN> state)'
            else
              search_in(field, q[:value])
            end
          when :search
            if field == :'*'
              full_text_query_string(as_values_array(q[:value]))
            else
              values = as_values_array(q[:value])
              values = values.map {|v| "*#{v}*" }
              search_in(field, values)
            end
          when :greater_than
            search_term(field, ">", q[:value])
          when :less_than
            search_term(field, "<", q[:value])
          when :prefix, :prefix_search
            if field == :'*'
              values = as_values_array(q[:value])
              values = values.map {|v| "#{v}*" }
              full_text_query_string(values)
            else
              values = as_values_array(q[:value])
              values = values.map {|v| "#{v}*" }
              search_in(field, values)
            end
          when :__in__
            search_in(field, q[:value])
          when :__not_in__
            search_not_in(field, q[:value])
          else
            raise "Operator: #{q[:operator]} not supported"
          end
        end.compact

        if conditions.empty?
          query_string = ""
        else
          query_string = "<#AND> (" + conditions.join(", ") + ")"
        end
      end

      def search_in(field, values)
        values = [values] unless values.kind_of?(Array)
        if [:objClass, :obj_id, :permalink, :lastChanged, :name].include?(field)
          fields = [field.to_s]
        else
          fields = (Fiona7::AttributeNamesFromQueries.new(field.to_s, @query).attributes || Fiona7::AttributeNamesFromCms.new(field.to_s).attributes).presence || [field.to_s]
          # NOTE: verity does not like more than 94 fields in its queries
          # so to be safe we limit the number of fields to 80
          fields = fields[0, 80]
        end

        sanitized_values = values.map {|v| "`#{self.class.sanitize(v)}`" }
        %|<#OR> ((#{sanitized_values.join(', ')}) <#IN> (#{fields.join(', ')}))|
      end

      def search_not_in(field, values)
        %|<#NOT> (#{search_in(field, values)})|
      end

      def search_term(field, operator, values, options={})
        values = [values] unless values.kind_of?(Array)
        join_op = options[:join] || "OR"
        negate  = options[:negate] ? "<#NOT> " : ""
        reverse = options[:reverse]

        condition = values.map do |value|
          if reverse
            %|(#{negate}`#{self.class.sanitize(value)}` #{operator} #{field})|
          else
            %|(#{negate}#{field} #{operator} `#{self.class.sanitize(value)}`)|
          end
        end.join(", ")

        %|(<##{join_op}> #{condition})|
      end

      def resolve_field_name(field)
        case field
        when :_obj_class
          :objClass
        when :_path
          :visiblePath
        when :_modification
          :__dummy__
        when :id
          :obj_id
        when :_permalink
          :permalink
        when :_last_changed
          :lastChanged
        when :_name
          :name
        else
          field
        end
      end

      def normalize_query(query)
        query = query.map do |q|
          q.symbolize_keys
          q[:operator] = q[:operator].to_sym
          q[:field] = q[:field].to_sym
          q
        end
      end

      def as_values_array(values)
        values = [values] unless values.kind_of?(Array)
        values
      end

      def extract_words(q)
        q = query.find {|q| q[:field] == :'*' && (q[:operator] == :prefix_search || q[:operator] == :search) }
        if q[:value].kind_of?(Array)
          q[:value]
        else
          [q[:value]]
        end
      end

      def full_text_query_string(words)
        words = words.map do |word|
          word = self.class.sanitize(word)
          word unless %w(and or not).include?(word.downcase)
        end.compact.join(", ")
        "<#AND> (#{words})"
      end

      def base_query_conditions
        conditions = {}
        conditions[:objTypes] = '<#ANY> (
        ("generic" <#IN> objType),
        ("document" <#IN> objType),
        ("publication" <#IN> objType)
      )'
        if @use_released
          conditions[:content] = '("released" <#IN> state)'
          conditions[:suppressExport] = '("0" <#IN> suppressExport)'
          conditions[:validFrom] = "(validFrom < #{Time.now.to_iso})"
          conditions[:validUntil] =  %!<#OR> (
                      (validUntil = ""),
                      (validUntil > #{Time.now.to_iso})
                    )!
        else
          conditions[:suppressExport] = '("0" <#IN> suppressExport)'
          end
        #conditions[:notWidget] = '("Widget" <#IN/NOT> objClass)'
        conditions[:notWidget] = '(objClass <#ENDS/NOT> "Widget")'
        conditions
      end

    def find_obj_class_in_query(query)
      obj_class_q = query.find {|q| q[:operator] == :equal && q[:field] == :_obj_class && !q[:value].kind_of?(Array) }
      obj_class_q[:value] if obj_class_q
    end

    def real_field_name_in_obj_class(obj_class, field)
      type_def = Fiona7::TypeRegister.instance.read(obj_class)
      if type_def
        attribute = type_def.find_attribute(field)
        if attribute
          field = attribute.real_name
        end
      end

      field
    end
    end

  end
end