module AnnotateRoutes

def self.do_annotations(options={})
  return unless(routes_exists?)
  position_after = options[:position_in_routes] != 'before'
  routes_map = `rake routes`.split(/\n/, -1)
  # In old versions of Rake, the first line of output was the cwd.  Not so
  # much in newer ones.  We ditch that line if it exists, and if not, we
  # keep the line around.
  routes_map.shift if(routes_map.first =~ /^\(in \//)
  header = [
    "#{PREFIX} (Updated #{Time.now.strftime("%Y-%m-%d %H:%M")})",
    "#"
  ] + routes_map.map { |line| "# #{line}".rstrip }
  (content, where_header_found) = strip_annotations(File.read(routes_file))
  changed = where_header_found != 0 # This will either be :before, :after, or
                                    # a number.  If the number is > 0, the
                                    # annotation was found somewhere in the
                                    # middle of the file.  If the number is
                                    # zero, no annotation was found.
  if(position_after)
    # Ensure we have adequate trailing newlines at the end of the file to
    # ensure a blank line separating the content from the annotation.
    content << '' if(content.last != '')
    # We're moving something from the top of the file to the bottom, so ditch
    # the spacer we put in the first time around.
    if(changed && where_header_found == :before)
      content.shift if(content.first == '')
    end
  else
    header = header << '' if(content.first != '' || changed)
  end
  content = position_after ? (content + header) : header + content
  write_contents(content)
  puts "Route file annotated."
end

def self.remove_annotations(options={})
  return unless(routes_exists?)
  (content, where_header_found) = strip_annotations(File.read(routes_file))
  content = strip_on_removal(content, where_header_found)
  write_contents(content)
  puts "Removed annotations from routes file."
end

def self.routes_exists?
  routes_exists = File.exists?(routes_file)
  puts "Can`t find routes.rb" if(!routes_exists)
  return routes_exists
end

def self.routes_file
  @routes_rb ||= File.join("config", "routes.rb")
end

def self.strip_annotations(content)
  real_content = []
  mode = :content
  line_number = 0
  header_found_at = 0
  content.split(/\n/, -1).each do |line|
    line_number += 1
    begin
      if(mode == :header)
        if(line !~ /\s*#/)
          mode = :content
          raise unless (line == '')
        end
      elsif(mode == :content)
        if(line =~ /^\s*#\s*== Route.*$/)
          header_found_at = line_number
          mode = :header
        else
          real_content << line
        end
      end
    rescue
      retry
    end
  end
  content_lines = real_content.count
  # By default assume the annotation was found in the middle of the file...
  where_header_found = header_found_at
  # ... unless we have evidence it was at the beginning ...
  where_header_found = :before if(header_found_at == 1)
  # ... or that it was at the end.
  where_header_found = :after if(header_found_at >= content_lines)
  return real_content, where_header_found
end

def self.strip_on_removal(content, where_header_found)
  if(where_header_found == :before)
    content.shift while(content.first == '')
  elsif(where_header_found == :after)
    content.pop while(content.last == '')
  end
  # TODO: If the user buried it in the middle, we should probably see about
  # TODO: preserving a single line of space between the content above and
  # TODO: below...
  return content
end

def self.write_contents(content)
  content << '' unless(content.last == '') # Make sure we end on a trailing
                                           # newline.
  File.open(routes_file, "wb") { |f| f.puts(content.join("\n")) }
end