module ChefMetal
  class Machine
    def initialize(machine_spec)
      @machine_spec = machine_spec
    end

    attr_reader :machine_spec

    def name
      machine_spec.name
    end

    def node
      machine_spec.node
    end

    # Sets up everything necessary for convergence to happen on the machine.
    # The node MUST be saved as part of this procedure.  Other than that,
    # nothing is guaranteed except that converge() will work when this is done.
    def setup_convergence(action_handler)
      raise "setup_convergence not overridden on #{self.class}"
    end

    def converge(action_handler)
      raise "converge not overridden on #{self.class}"
    end

    def cleanup_convergence(action_handler)
      raise "cleanup_convergence not overridden on #{self.class}"
    end

    def execute(action_handler, command, options = {})
      raise "execute not overridden on #{self.class}"
    end

    def execute_always(command, options = {})
      raise "execute_always not overridden on #{self.class}"
    end

    def read_file(path)
      raise "read_file not overridden on #{self.class}"
    end

    def download_file(action_handler, path, local_path)
      raise "read_file not overridden on #{self.class}"
    end

    def write_file(action_handler, path, content)
      raise "write_file not overridden on #{self.class}"
    end

    def upload_file(action_handler, local_path, path)
      raise "write_file not overridden on #{self.class}"
    end

    def create_dir(action_handler, path)
      raise "create_dir not overridden on #{self.class}"
    end

    # Delete file
    def delete_file(action_handler, path)
      raise "delete_file not overridden on #{self.class}"
    end

    # Return true if directory, false/nil if not
    def is_directory?(path)
      raise "is_directory? not overridden on #{self.class}"
    end

    # Return true or false depending on whether file exists
    def file_exists?(path)
      raise "file_exists? not overridden on #{self.class}"
    end

    # Return true or false depending on whether remote file differs from local path or content
    def files_different?(path, local_path, content=nil)
      raise "file_different? not overridden on #{self.class}"
    end

    # Set file attributes { mode, :owner, :group }
    def set_attributes(action_handler, path, attributes)
      raise "set_attributes not overridden on #{self.class}"
    end

    # Get file attributes { :mode, :owner, :group }
    def get_attributes(path)
      raise "get_attributes not overridden on #{self.class}"
    end

    # Ensure the given URL can be reached by the remote side (possibly by port forwarding)
    # Must return the URL that the remote side can use to reach the local_url
    def make_url_available_to_remote(local_url)
      raise "make_url_available_to_remote not overridden on #{self.class}"
    end

    def disconnect
      raise "disconnect not overridden on #{self.class}"
    end

    # TODO get rid of the action_handler attribute, that is ridiculous
    # Detect the OS on the machine (assumes the machine is up)
    # Returns a triplet:
    #   platform, platform_version, machine_architecture = machine.detect_os(action_handler)
    # This triplet is suitable for passing to the Chef metadata API:
    # https://www.opscode.com/chef/metadata?p=#{platform}&pv=#{platform_version}&m=#{machine_architecture}
    def detect_os(action_handler)
      raise "detect_os not overridden on #{self.class}"
    end
  end
end