require 'blacklight_range_limit/segment_calculation'

module BlacklightRangeLimit
  module RangeLimitBuilder
    extend ActiveSupport::Concern
    include BlacklightRangeLimit::SegmentCalculation

    included do
      # Use setters so not to propagate changes
      self.default_processor_chain += [:add_range_limit_params]
    end

    # Method added to to fetch proper things for date ranges.
    def add_range_limit_params(solr_params)
       ranged_facet_configs =
         blacklight_config.facet_fields.select { |key, config| config.range }
       # In ruby 1.8, hash.select returns an array of pairs, in ruby 1.9
       # it returns a hash. Turn it into a hash either way.
       ranged_facet_configs = Hash[ ranged_facet_configs ] unless ranged_facet_configs.kind_of?(Hash)

       ranged_facet_configs.each_pair do |field_key, config|
        solr_params["stats"] = "true"
        solr_params["stats.field"] ||= []
        solr_params["stats.field"] << config.field

        range_config = BlacklightRangeLimit.range_config(blacklight_config, config.field)

        hash =  blacklight_params["range"] && blacklight_params["range"][field_key] ?
          blacklight_params["range"][field_key] :
          {}

        if !hash["missing"].blank?
          # missing specified in request params
          solr_params[:fq] ||= []
          solr_params[:fq] << "-#{config.field}:[* TO *]"

        elsif !(hash["begin"].blank? && hash["end"].blank?)
          # specified in request params, begin and/or end, might just have one
          start = hash["begin"].blank? ? "*" : hash["begin"]
          finish = hash["end"].blank? ? "*" : hash["end"]

          solr_params[:fq] ||= []
          solr_params[:fq] << "#{config.field}: [#{start} TO #{finish}]"

          if (range_config[:segments] != false && start != "*" && finish != "*")
            # Add in our calculated segments, can only do with both boundaries.
            add_range_segments_to_solr!(solr_params, field_key, start.to_i, finish.to_i)
          end

        elsif (range_config[:segments] != false &&
               boundaries = range_config[:assumed_boundaries])
          # assumed_boundaries in config
          add_range_segments_to_solr!(solr_params, field_key, boundaries[0], boundaries[1])
        end
      end

      return solr_params
    end


    # Another processing method, this one is NOT included in default processing chain,
    # it is specifically swapped in *instead of* add_range_limit_params for
    # certain ajax requests that only want to fetch range limit segments for
    # ONE field. 
    #
    # It turns off facetting and sets rows to 0 as well, only results for
    # single specified field are needed. 
    #
    # Specified field and parameters are specified in incoming parameters
    # range_field, range_start, range_end
    def fetch_specific_range_limit(solr_params)
      field_key = blacklight_params[:range_field] # what field to fetch for
      start = blacklight_params[:range_start].to_i
      finish = blacklight_params[:range_end].to_i

      add_range_segments_to_solr!(solr_params, field_key, start, finish )

      # Remove all field faceting for efficiency, we won't be using it.
      solr_params.delete("facet.field")
      solr_params.delete("facet.field".to_sym)

      # We don't need any actual rows either
      solr_params[:rows] = 0      

      return solr_params
    end

  end
end