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
  Array(@exception.backtrace)
end

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

def expand_backtrace
  @exception.backtrace.unshift(
    @exception.to_s.split("\n")
  ).flatten!
end

def extract_file_and_line_number(trace)
  # Split by the first colon followed by some digits, which works for both
  # Windows and Unix path styles.
  file, line = trace.match(/^(.+?):(\d+).*$/, &:captures) || trace
  [file, line.to_i]
end

def framework_trace
  clean_backtrace(:noise)
end

def full_trace
  clean_backtrace(:all)
end

def initialize(backtrace_cleaner, exception)
  @backtrace_cleaner = backtrace_cleaner
  @exception = original_exception(exception)
  expand_backtrace if exception.is_a?(SyntaxError) || exception.cause.is_a?(SyntaxError)
end

def original_exception(exception)
  if @@rescue_responses.has_key?(exception.cause.class.name)
    exception.cause
  else
    exception
  end
end

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

def source_extracts
  backtrace.map do |trace|
    file, line_number = extract_file_and_line_number(trace)
    {
      code: source_fragment(file, line_number),
      line_number: 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.exist?(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

def traces
  application_trace_with_ids = []
  framework_trace_with_ids = []
  full_trace_with_ids = []
  full_trace.each_with_index do |trace, idx|
    trace_with_id = { id: idx, trace: trace }
    if application_trace.include?(trace)
      application_trace_with_ids << trace_with_id
    else
      framework_trace_with_ids << trace_with_id
    end
    full_trace_with_ids << trace_with_id
  end
  {
    "Application Trace" => application_trace_with_ids,
    "Framework Trace" => framework_trace_with_ids,
    "Full Trace" => full_trace_with_ids
  }
end