# Adapted from http://snippets.dzone.com/posts/show/2389

class FixtureRevert

  def self.revert(class_name)
    
    # Get the "Class" object from the class name        
    model_class = class_name.is_a?(String) ? Object.const_get(class_name) : class_name
    return "Only ActiveRecord objects are supported" unless check_for_ar(model_class)
    yaml_content =  "# Read about fixtures at http://ar.rubyonrails.org/classes/Fixtures.html\n"
    yaml_content += "one:\n"
    
    # get if first!   
    model_class.columns.each { |column|
      
      yaml_content += "  " + column.name + ": "
  
      yaml_content += contents_for_column(column)
      
      yaml_content += "\n"      
    }  
    
    if write_fixture_file(model_class, yaml_content)
      puts "Fixture for #{model_class.to_s} has been generated"
    else
      puts "Fixture revert for #{model_class.to_s} was canceled"
    end
  end  
  
  # Write the <fixture> yaml file  in the test/fixtures folder
  def self.write_fixture_file(model_class, yaml_content)
    
    path = ENV['DEST'] || "#{RAILS_ROOT}/test/fixtures"
    db   = ENV['DB']   || 'test'
    
    if File.exists?("#{path}/#{model_class.table_name}.yml")
      print "Fixture for #{model_class.to_s} already exists, overwrite? [yn]"
      return false if $stdin.gets.chomp =~ /n/
    end
    
    File.open("#{path}/#{model_class.table_name}.yml", 'wb') do |file|    
      file.write yaml_content 
      file.close    
    end
    return true
  end
  
  def self.contents_for_column(column)
    return column.default.to_s if column.default
    content = case column.type
      when :integer then "1"
      when :string then "I like turtles"
      when :text then "This is a longer description of why I like turtles"
      when :boolean then "true"
      when :datetime then "<%= (Time.now - 100).to_s(:db) %>" 
      when :decimal then "0.0"
      when :float then "1.1"
      when :time then "<%= (Time.now - 100).to_s(:db) %>"
      when :date then "<%= (Date.today - 1).to_s(:db) %>"  
    else
      "I have no clue" 
    end
    return content
  end
  
  def self.check_for_ar(model)
    model.ancestors.include?(ActiveRecord::Base)
  end
  
end