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

    def initialize(prefix, keywords)
      if keywords.is_a?(Hash)
        @sets = keywords.inject([]) { |a, (field, query)| a | Sets.new(prefix, query, field) }
        @search_identifier = keywords.hash
      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)
      return [] if sets.empty?

      # TODO : cache this for X seconds, X seconds being customizable
      Lunar.redis.zunion dist_key, sets.size, *sets
      
      if block_given?
        ResultSet.new(dist_key, &block)
      else
        ResultSet.new(dist_key, &@finder)
      end
    end
  
  protected
    def dist_key
      Lunar.nest[:Results][search_identifier]
    end
  end
end