#--
# Copyright (C) 2008 Dimitrij Denissenko
# Please read LICENSE document for more information.
#++
class Change < ActiveRecord::Base
  belongs_to :changeset
  belongs_to :repository

  def previous_revision
    @previous_revision ||= repository.history(path, revision).reject do |hrev|
      hrev == revision
    end.first || 0
  end

  def unified_diff(max_size = 512.kilobyte)
    if @unified_diff.nil? && diffable?
      node = repository.node(path, revision)
      if node.size < max_size
        @unified_diff = repository.unified_diff(path, previous_revision, revision)
      end      
    end
  	@unified_diff ||= ''
  end
  
  def diffable?
    ENABLE_SUBVERSION && self.name == 'M'
  end
  
end