require 'rbconfig'
require 'fileutils'

require 'facet/fileutils/safe_ln'
require 'facet/string/tabto'
require 'facet/module/basename'
require 'facet/module/attr_setter'

require 'facet/filelist'
require 'facet/openobject'

#  _____        _     ___                  ___ _
# |_   _|_ _ __| |__ | _ ) __ _ ___ ___   / __| |__ _ ______
#   | |/ _` (_-< / / | _ \/ _` (_-</ -_) | (__| / _` (_-<_-<
#   |_|\__,_/__/_\_\ |___/\__,_/__/\___|  \___|_\__,_/__/__/
#

# Base class for reap tasks.
#
# Here's an oh so simple example:
#
#   class MyTask < Reap::Task
#
#     register 'mytask'
#
#     default_desc 'this is a custom reap task'
#
#     attr_accessor :message
#
#     def init
#       @message ||= master['default'] || 'None Found!'
#     end
#
#     def run
#       puts @message
#     end
#   end
#
# The corresponding settings in the ProjectInfo file will then be:
#
#   default: Default text, if any.
#
#   myname:
#     TASK: mytask
#     message: Message text, if any.
#

module Reap

  @registry ||= {}

  # Hash of all task classes
  def self.registry ; @registry ; end

  # Hash of tasks available to this project
  def self.tasks
    unless @tasks
      @tasks = {}
      @registry.each { |name, klass|
        @tasks[name] = klass if klass.verify?
      }
    end
    @tasks
  end

  def self.register
    $PROJECT_INFO = ProjectInfo.new( $PROJECT_FILE )

    #@registry ||= {}
    #ObjectSpace.each_object(Class) { |klass|
    #  if klass < ::Reap::Task
    #    if klass.verify
    #      @registry[klass.basename.downcase] = klass
    #    end
    #  end
    #}
  end

#   def self.initialize
#     @tasks ||= {}
#     registry.each do |name, klass|
#       @tasks[name] = klass.new
#     end
#   end


  class Task

    include ::Config
    include ::FileUtils

    RUBY = CONFIG['ruby_install_name']

    class << self

      def inherited( base )
        Reap.registry[base.task_name] = base
      end

      def task_name ; basename.downcase ; end

      def task_desc( text=nil, &block )
        return @task_desc = proc { text } if text
        return @task_desc = block if block_given?
        return @task_desc.call
      end
      #def task_desc ; '(no desciption given)' ; end

      def task_help( text=nil, &block )
        return @task_help = proc { text } if text
        return @task_help = block if block_given?
        return @task_help.call
      end

      def task_attr( name )
        define_method(name) { @task }
      end

      def section_required( val ) ; @section_required = val ; end
      def section_required?       ; @section_required ; end

      def verify?
        if section_required?
          return $PROJECT_INFO.info.key?(task_name)
        end
        true
      end

#       def master_attributes ; @master_attributes ||= [] ; end
#
#       # Use this DSL method to define master task attributes.
#       def attr_master( *names )
#         attr_accessor *names
#         @master_attributes ||= []
#         @master_attributes |= names.collect { |n| n.to_s }
#       end

      # properties not to be looked up in master
      # if they are not in regular task section

      def task_only_properties ; @task_only_properties ||= [] ; end
      def task_only_property( *names )
        @task_only_properties ||= []
        @task_only_properties |= names.collect { |n| n.to_s }
      end

    end #<< class

    # instance methods

    def task_name ; self.class.task_name ; end
    def task_desc ; self.class.task_desc ; end
    def task_help ; self.class.task_help ; end

    def section_required? ; self.class.section_required? ; end

    #def master ; ::ProjectInfo.info ; end
    def master  ; @master  ; end
    def section ; @section ; end
    def task    ; @task    ; end

    def initialize( *args )
      @master = CascadingOpenObject.new( $PROJECT_INFO )
      section = @master[task_name]
      case section
      when Array
        section.each do |s|
          initiate( s )
        end
      else
        initiate( section )
      end
    end

    # Per section

    def initiate( section )
      @section = CascadingOpenObject.new( section )

      task_properties = {}
      #self.class.task_only_properties.each { |t| section[t] ||= nil }
      task_properties = CascadingOpenObject.new( section )
      task_properties.__parent__ = @master
      @task = task_properties

      init #task
      run #task
    end

#     def set( sec )
# 
#       #@task = @section #TaskProperties.new( @master, @section )
# 
#       #self.class.master_attributes.each do |k,v|
#       #  send( "#{k}=", @master[k] )
#       #end
# 
#       #@section.each do |k,v|
#       #  send( "#{k}=", v )
#       #end
#     end

    # the two primary methods

    def init
      raise "not implemented for '#{task_name}' task"
    end

    def run
      raise "no action defined for task #{task_name}"
    end

    # Task support methods

    def use_subsection( name )
      subsection = @section.__send__(name)
      if subsection
        subsection.__parent__ = @section
        @task = subsection
      end
    end

    def sh( arg )
      puts arg
      system arg unless $PRETEND
    end

  end #class Task

end #module Reap