require 'patch_version_like_methods'

class PatchVersion < ActiveRecord::Base
  belongs_to                  :patch
  validates_presence_of       :for_upstream_version
  after_save                  :save_patch_text  # "after" because of the id
  after_destroy               :remove_patch_file
  include PatchVersionLikeMethods

  @patch_dir = PATCH_REPOSITORY + case ENV['RAILS_ENV']
                                  when 'production'
                                    ''
                                  else
                                    File.join('', ENV['RAILS_ENV'])
                                  end

  class <<self
    def patch_dir;                 @patch_dir;                 end
  end

  def patch_dir; self.class.patch_dir; end
  def path
    case id
    when nil
      nil   # If still unsaved, return nil as the path
    else
      File.join(patch_dir, id.to_s)
    end
  end

  def text=(new_text); @text = new_text; end
  def applied_since_version=(new_version); super(new_version == '' ? nil : new_version) end
  def for_upstream_version=(new_version); super(new_version == '' ? nil : new_version) end
  def version
    if patch.nil?
      nil
    else
      i = patch.patch_versions.index(self)
      i.nil? ? nil : i+1
    end
  end

  def save_patch_text
    if defined? @text
      File.open(path, "w") do |f|
        f.print @text
      end
    end
  end

  def remove_patch_file
    File.unlink(path) if path and File.exists? path
  end
end