require "piston_core/revision"
 
module PistonCore
  class Repository
    class UnhandledUrl < RuntimeError; end
 
    class << self
      def logger
        @@logger
      end
 
      def logger=(logger)
        @@logger = logger
        PistonCore::Revision.logger = @@logger
      end
 
      def guess(url)
        logger.debug {"Guessing the repository type of #{url.inspect}"}
 
        handler = self.handlers.detect do |handler|
          handler.understands_url?(url)
        end
 
        raise UnhandledUrl, "No internal handlers found for #{url.inspect}.  Do you want to help ?" if handler.nil?
        handler.new(url)
      end
 
      @@handlers = Array.new
      def handlers
        @@handlers
      end
    end
 
    attr_reader :url
 
    def initialize(url)
      @url = url
    end
 
    def logger
      self.class.logger
    end
 
    def at(revision)
      logger.debug {"Targeting #{self} at #{revision.inspect}"}
      PistonCore::Revision.new(self, revision)
    end
 
    def to_s
      "PistonCore::Repository(#{@url})"
    end
  end
end