require "set"

module Celluloid
  module Internals
    class Handlers
      def initialize
        @handlers = Set.new
      end

      def handle(*patterns, &block)
        patterns.each do |pattern|
          handler = Handler.new pattern, block
          @handlers << handler
        end
      end

      # Handle incoming messages
      def handle_message(message)
        handler = @handlers.find { |h| h.match(message) }
        handler.call message if handler
        handler
      end
    end

    # Methods blocking on a call to receive
    class Handler
      def initialize(pattern, block)
        @pattern = pattern
        @block = block
      end

      # Match a message with this receiver's block
      def match(message)
        @pattern === message
      end

      def call(message)
        @block.call message
      end
    end
  end
end
