module Lunar
  class Search
    attr :sets, :prefix, :search_identifier, :fuzzy_sets, :key_value_sets

    def initialize(prefix, keywords)
      if keywords.is_a?(Hash)
        if fuzzy_hash = keywords.delete(:fuzzy)
          @fuzzy_sets = fuzzy_hash.inject([]) { |a, (field, query)|
            a | FuzzySets.new(prefix, query, field)
          }
          @search_identifier = fuzzy_hash.hash
        else
          @key_value_sets = 
            keywords.map { |field, val| Sets.new(prefix, val, field) }.flatten

          @search_identifier = keywords.hash
        end
      else
        @sets = Sets.new(prefix, keywords)
        @search_identifier = keywords.hash
      end

      @prefix = prefix

      # Default finder, uses Ohm style finding
      @finder = lambda { |id| prefix[id] }
    end

    def results(&block)
      block ||= @finder

      if sets
        if sets.empty?
          return []
        else
          if not Lunar.redis.exists(dist_key)
            Lunar.redis.zunion dist_key, sets.size, *sets
            Lunar.redis.expire dist_key, Lunar.ttl
          end
          SortedResultSet.new(dist_key, &block)
        end
      elsif key_value_sets
        if key_value_sets.empty?
          return []
        else
          Lunar.redis.zinter dist_key, key_value_sets.size, *key_value_sets
          SortedResultSet.new(dist_key, &block)
        end
      elsif fuzzy_sets
        if fuzzy_sets.empty?
          return []
        else
          if not Lunar.redis.exists(dist_key)
            Lunar.redis.sunionstore dist_key, *fuzzy_sets
            Lunar.redis.expire dist_key, Lunar.ttl
          end
          UnsortedResultSet.new(dist_key, &block)
        end
      end
    end
  
  protected
    def dist_key
      Lunar.nest[:Results][search_identifier]
    end
  end
end