require "revision"

class Mercurial

  def initialize(parser = MercurialLogParser.new)
    @parser = parser
  end
  
  def checkout(target_directory, revision = nil) 
  end
  
  def latest_revision(project) 
    Dir.chdir(project.local_checkout) do
      self.execute(self.pull_command)
      @parser.parse_log(execute(self.log_command("tip"))).first
    end
  end
  
  def revisions_since(project, revision_number)
    Dir.chdir(project.local_checkout) do
      self.execute(self.pull_command)
      revs = @parser.parse_log(self.execute(self.log_command(revision_number)))
      revs.delete_if do |rev|
        rev.number == revision_number
      end
      revs
    end    
  end
  
  def update(project, revision) 
    Dir.chdir(project.local_checkout) do
      self.execute(self.pull_command)
      self.execute(self.update_command(revision))
    end
  end
  
  def pull_command
    "hg pull"
  end
  
  def update_command(revision=nil)
    command = "hg update"
    command << " #{revision.number}" unless revision.nil?
    command
  end
  
  def log_command(revision_number="tip")
    "hg log -v -r tip:#{revision_number}"
  end
  
  protected
  
  def execute(command)
    `#{command}`    
  end
end