=begin
#==============================================================================
 ** Learn and Replace
 Author: Hime
 Date: Jan 26, 2013
------------------------------------------------------------------------------
 ** Change log
 Jan 26, 2013
   - Initial release
------------------------------------------------------------------------------   
 ** Terms of Use
 * Free to use in non-commercial projects
 * Contact me for commercial use
 * No real support. The script is provided as-is
 * Will do bug fixes, but no compatibility patches
 * Features may be requested but no guarantees, especially if it is non-trivial
 * Preserve this header
------------------------------------------------------------------------------
 ** Description
 
 This script allows you to have a newly learned skill "replace" an old
 skill. For example, if you have Fire 1, Fire 2, and Fire 3, and you want
 to simulate skill mastery where higher levels of the skill replace lower
 levels, then learning Fire 2 may replace Fire 1.
 
------------------------------------------------------------------------------
 ** Usage
 
 Note-tag Learning objects with
 
   <replace: ID1 ID2 ID3 ... >
   
 Where the ID's are the ID's of skills that will be forgotten upon
 learning the new skill
#==============================================================================
=end
$imported = {} if $imported.nil?
$imported["Tsuki_LearnReplace"] = true
#==============================================================================
# ** Configuration
#==============================================================================
module TH
  module Learn_Replace
    Regex = /<replace: (.*)>/i
  end
end
#==============================================================================
# ** Rest of the script
#============================================================================== 

module RPG
  class Class::Learning
    
    def replace_skills
      return @replace_skills unless @replace_skills.nil?
      load_notetag_replace_skills
      return @replace_skills
    end
    
    def load_notetag_replace_skills
      res = self.note.match(TH::Learn_Replace::Regex)
      @replace_skills = res ? res[1].scan(/\d+/).map!{|v|v.to_i} : []
    end
  end
end

class Game_Actor < Game_Battler
  
  alias :th_learn_replace_level_up :level_up
  def level_up
    th_learn_replace_level_up
    self.class.learnings.each do |learning|
      replace_skills(learning.replace_skills) if learning.level == @level
    end
  end
  
  def replace_skills(skill_ids)
    skill_ids.each {|id| forget_skill(id)}
  end
end