#
#   irb/extend-command.rb - irb command extend
#   	$Release Version: 0.9$
#   	$Revision$
#   	$Date$
#   	by Keiju ISHITSUKA(keiju@ishitsuka.com)
#
# --
#
#   
#
module IRB
  #
  # IRB extended command
  #
  module ExtendCommandBundle
    EXCB = ExtendCommandBundle

    NO_OVERRIDE = 0
    OVERRIDE_PRIVATE_ONLY = 0x01
    OVERRIDE_ALL = 0x02

    def irb_exit(ret = 0)
      irb_context.exit(ret)
    end

    def irb_context
      IRB.CurrentContext
    end

    @ALIASES = [
      [:context, :irb_context, NO_OVERRIDE],
      [:conf, :irb_context, NO_OVERRIDE],
      [:irb_quit, :irb_exit, OVERRIDE_PRIVATE_ONLY],
      [:exit, :irb_exit, OVERRIDE_PRIVATE_ONLY],
      [:quit, :irb_exit, OVERRIDE_PRIVATE_ONLY],
    ]

    @EXTEND_COMMANDS = [
      [:irb_current_working_workspace, :CurrentWorkingWorkspace, "irb/cmd/chws",
	[:irb_print_working_workspace, OVERRIDE_ALL],
	[:irb_cwws, OVERRIDE_ALL],
	[:irb_pwws, OVERRIDE_ALL],
#	[:irb_cww, OVERRIDE_ALL],
#	[:irb_pww, OVERRIDE_ALL],
	[:cwws, NO_OVERRIDE],
	[:pwws, NO_OVERRIDE],
#	[:cww, NO_OVERRIDE],
#	[:pww, NO_OVERRIDE],
	[:irb_current_working_binding, OVERRIDE_ALL],
	[:irb_print_working_binding, OVERRIDE_ALL],
	[:irb_cwb, OVERRIDE_ALL],
	[:irb_pwb, OVERRIDE_ALL],
#	[:cwb, NO_OVERRIDE],
#	[:pwb, NO_OVERRIDE]
      ],
      [:irb_change_workspace, :ChangeWorkspace, "irb/cmd/chws",
	[:irb_chws, OVERRIDE_ALL],
#	[:irb_chw, OVERRIDE_ALL],
	[:irb_cws, OVERRIDE_ALL],
#	[:irb_cw, OVERRIDE_ALL],
	[:chws, NO_OVERRIDE],
#	[:chw, NO_OVERRIDE],
	[:cws, NO_OVERRIDE],
#	[:cw, NO_OVERRIDE],
	[:irb_change_binding, OVERRIDE_ALL],
	[:irb_cb, OVERRIDE_ALL],
	[:cb, NO_OVERRIDE]],

      [:irb_workspaces, :Workspaces, "irb/cmd/pushws",
	[:workspaces, NO_OVERRIDE],
	[:irb_bindings, OVERRIDE_ALL],
	[:bindings, NO_OVERRIDE]],
      [:irb_push_workspace, :PushWorkspace, "irb/cmd/pushws",
	[:irb_pushws, OVERRIDE_ALL],
#	[:irb_pushw, OVERRIDE_ALL],
	[:pushws, NO_OVERRIDE],
#	[:pushw, NO_OVERRIDE],
	[:irb_push_binding, OVERRIDE_ALL],
	[:irb_pushb, OVERRIDE_ALL],
	[:pushb, NO_OVERRIDE]],
      [:irb_pop_workspace, :PopWorkspace, "irb/cmd/pushws",
	[:irb_popws, OVERRIDE_ALL],
#	[:irb_popw, OVERRIDE_ALL],
	[:popws, NO_OVERRIDE],
#	[:popw, NO_OVERRIDE],
	[:irb_pop_binding, OVERRIDE_ALL],
	[:irb_popb, OVERRIDE_ALL],
	[:popb, NO_OVERRIDE]],

      [:irb_load, :Load, "irb/cmd/load"],
      [:irb_require, :Require, "irb/cmd/load"],
      [:irb_source, :Source, "irb/cmd/load", 
	[:source, NO_OVERRIDE]],

      [:irb, :IrbCommand, "irb/cmd/subirb"],
      [:irb_jobs, :Jobs, "irb/cmd/subirb", 
	[:jobs, NO_OVERRIDE]],
      [:irb_fg, :Foreground, "irb/cmd/subirb", 
	[:fg, NO_OVERRIDE]],
      [:irb_kill, :Kill, "irb/cmd/subirb", 
	[:kill, OVERRIDE_PRIVATE_ONLY]],
    ]

    def EXCB.install_extend_commands
      for args in @EXTEND_COMMANDS
	def_extend_command(*args)
      end
    end

    # aliases = [commans_alias, flag], ...
    def EXCB.def_extend_command(cmd_name, cmd_class, load_file = nil, *aliases)
      case cmd_class
      when Symbol
	cmd_class = cmd_class.id2name
      when String
      when Class
	cmd_class = cmd_class.name
      end

      if load_file
	eval %[
	  def #{cmd_name}(*opts, &b)
	    require "#{load_file}"
	    eval %[
	      def #{cmd_name}(*opts, &b)
		ExtendCommand::#{cmd_class}.execute(irb_context, *opts, &b)
	      end
	    ]
	    send :#{cmd_name}, *opts, &b
	  end
	]
      else
	eval %[
	  def #{cmd_name}(*opts, &b)
	    ExtendCommand::#{cmd_class}.execute(irb_context, *opts, &b)
	  end
	]
      end

      for ali, flag in aliases
	@ALIASES.push [ali, cmd_name, flag]
      end
    end

    # override = {NO_OVERRIDE, OVERRIDE_PRIVATE_ONLY, OVERRIDE_ALL}
    def install_alias_method(to, from, override = NO_OVERRIDE)
      to = to.id2name unless to.kind_of?(String)
      from = from.id2name unless from.kind_of?(String)

      if override == OVERRIDE_ALL or
	  (override == OVERRIDE_PRIVATE_ONLY) && !respond_to?(to) or
	  (override == NO_OVERRIDE) &&  !respond_to?(to, true)
	target = self
	(class<<self;self;end).instance_eval{
	  if target.respond_to?(to, true) && 
	      !target.respond_to?(EXCB.irb_original_method_name(to), true)
	    alias_method(EXCB.irb_original_method_name(to), to) 
	  end
	  alias_method to, from
	}
      else
	print "irb: warn: can't alias #{to} from #{from}.\n"
      end
    end

    def self.irb_original_method_name(method_name)
      "irb_" + method_name + "_org"
    end

    def EXCB.extend_object(obj)
      unless (class<<obj;ancestors;end).include?(EXCB)
	super
	for ali, com, flg in @ALIASES
	  obj.install_alias_method(ali, com, flg)
	end
      end
    end

    install_extend_commands
  end

  # extension support for Context
  module ContextExtender
    CE = ContextExtender

    @EXTEND_COMMANDS = [
      [:eval_history=, "irb/ext/history.rb"],
      [:use_tracer=, "irb/ext/tracer.rb"],
      [:math_mode=, "irb/ext/math-mode.rb"],
      [:use_loader=, "irb/ext/use-loader.rb"],
    ]

    def CE.install_extend_commands
      for args in @EXTEND_COMMANDS
	def_extend_command(*args)
      end
    end

    def CE.def_extend_command(cmd_name, load_file, *aliases)
      Context.module_eval %[
        def #{cmd_name}(*opts, &b)
	  require "#{load_file}"
	  send :#{cmd_name}, *opts, &b
	end
	for ali in aliases
	  alias_method ali, cmd_name
	end
      ]
    end

    CE.install_extend_commands
  end
end