require 'rake'
require 'chrysalis/loader'


# Intercept Rake's methods for declaring tasks.
#
# Task interception is used to construct internal tables, and synthesize
# tasks in the <em>all:</em> namespace.
#
# Tasks declared in the course of loading a dependency are intercepted
# completely, and are unknown to Rake.  This prevents dependencies from
# polluting the task space of their dependents.
#
# Tasks declared by the main rakefile are forwarded to Rake's original methods,
# ensuring that the system remains consistent.

class Object
  
  alias_method :rake_task, :task
  def task(args, &block)
    task_name, deps = Rake.application.resolve_args(args)
    Chrysalis::Loader.instance.task_intercept(task_name) { rake_task(args, &block) }
  end

  alias_method :rake_file, :file
  def file(args, &block)
    task_name, deps = Rake.application.resolve_args(args)
    Chrysalis::Loader.instance.file_task_intercept(task_name) { rake_file(args, &block) }
  end

  alias_method :rake_file_create, :file_create
  def file_create(args, &block)
    task_name, deps = Rake.application.resolve_args(args)
    Chrysalis::Loader.instance.file_task_intercept(task_name) { rake_file_create(args, &block) }
  end

  #--
  # NOTE: Intercepting directory tasks is unnecessary, because Rake itself
  #       implements them as a set of file_create tasks.  Thus, the interception
  #       of file_create is sufficient.
  #alias_method :rake_directory, :directory
  #def directory(dir)
  #end

  alias_method :rake_multitask, :multitask
  def multitask(args, &block)
    task_name, deps = Rake.application.resolve_args(args)
    Chrysalis::Loader.instance.task_intercept(task_name) { rake_multitask(args, &block) }
  end

  alias_method :rake_namespace, :namespace
  def namespace(name=nil, &block)
    Chrysalis::Loader.instance.namespace_intercept(name, block) { rake_namespace(name, &block) }
  end

  alias_method :rake_rule, :rule
  def rule(args, &block)
    Chrysalis::Loader.instance.rule_intercept { rake_rule(args, &block) }
  end

  alias_method :rake_desc, :desc
  def desc(comment)
    Chrysalis::Loader.instance.desc_intercept(comment) { rake_desc(comment) }
  end

end


module Rake
  
  class Application
  
    alias_method :rake_top_level, :top_level
    
    # Invoked after the main rakefile has been loaded, but before any tasks are
    # executed.
    #
    # Chrysalis reimplements this method for the purpose of hooking into the
    # loader and seeding the <em>all:</em> namespace with tasks, prior to
    # retrieval of dependencies.
    #
    # After invoking the hook, execution proceeds with Rake's original method.
    def top_level
      Chrysalis.post :rakefile_loaded
      rake_top_level
    end
  
  end
  
end