class ActionDispatch::ExceptionWrapper

def self.status_code_for_exception(class_name)
  Rack::Utils.status_code(@@rescue_responses[class_name])
end

def application_trace
  clean_backtrace(:silent)
end

def backtrace_cleaner
  @backtrace_cleaner ||= @env['action_dispatch.backtrace_cleaner']
end

def clean_backtrace(*args)
  if backtrace_cleaner
    backtrace_cleaner.clean(@exception.backtrace, *args)
  else
    @exception.backtrace
  end
end

def framework_trace
  clean_backtrace(:noise)
end

def full_trace
  clean_backtrace(:all)
end

def initialize(env, exception)
  @env = env
  @exception = original_exception(exception)
end

def original_exception(exception)
  if registered_original_exception?(exception)
    exception.original_exception
  else
    exception
  end
end

def registered_original_exception?(exception)
  exception.respond_to?(:original_exception) && @@rescue_responses.has_key?(exception.original_exception.class.name)
end

def rescue_template
  @@rescue_templates[@exception.class.name]
end

def source_extract
  if application_trace && trace = application_trace.first
    file, line, _ = trace.split(":")
    @file = file
    @line_number = line.to_i
    source_fragment(@file, @line_number)
  end
end

def source_fragment(path, line)
  return unless Rails.respond_to?(:root) && Rails.root
  full_path = Rails.root.join(path)
  if File.exists?(full_path)
    File.open(full_path, "r") do |file|
      start = [line - 3, 0].max
      lines = file.each_line.drop(start).take(6)
      Hash[*(start+1..(lines.count+start)).zip(lines).flatten]
    end
  end
end

def status_code
  self.class.status_code_for_exception(@exception.class.name)
end