Batch header converter for ReaScripts

converter.rb

DEFAULT_VERSION = '0.1'.freeze

PREFIX = ' * '.freeze
INDENT = "\x20" * 2

LOG_REGEX = /
  \s*(?:(?:--)?\]\]|\*\/)
  (.+
  Changelog\s*:\n
  (.+?)\n\s*
  ((?:--)?\]\]|\*\/))
/xm.freeze

SPK_REGEX = /(\/\/ EEL.+spk.+(\d{2})\.(\d{2})\.(\d{4}).*)(\n+)/.freeze

VER_REGEX = /
  (?:#{Regexp.escape PREFIX})
  \s*v([\d\.]+)\s*([^\n]+)
/x.freeze

Version = Struct.new :name, :changelog

def process_file(path, encoding = Encoding::UTF_8)
  file = File.new path, 'r+t', :encoding => encoding
  before = file.read

  return if before =~ /(?<!\n\n)(?:\*|\/\/|--) Version\s*:/

  # fix the usual changelog format
  after = before.sub LOG_REGEX do |match|
    versions = []
    trailing = $1.chomp("--[[\n#{PREFIX}").chomp("/**\n#{PREFIX}").rstrip
    close = $3

    $2.lines {|line|
      if VER_REGEX =~ line
        ver = Version.new $1, $2
        versions << ver
      else
        if versions.empty?
          ver = Version.new DEFAULT_VERSION, String.new
          versions << ver

          warn "first changelog line in %s is not a version – assuming %s:" \
            % [path, ver.name]
          warn line + "\n\n"
        end

        versions.last.changelog += "\n" + line
      end
    }

    if versions.empty?
      warn "Cannot find any version in #{path}"
      next match
    end

    ver = "#{PREFIX}Version: #{versions.first.name}"
    "\n#{PREFIX.rstrip}\n" + ver + "\n" + close + trailing
  end

  # fix scripts with a newline before the version tag
  if before.include? "\n// Version"
    after = before.sub "\n// Version", '// Version'
  end

  # fix spk's scripts
  if before =~ SPK_REGEX
    after = before.sub SPK_REGEX, "\\1\n// Version: 0.\\4.\\3.\\2\\5"
  end

  # fix scripts without any metadata
  if after == before
    warn "no version found in %s – creating %s" % [path, DEFAULT_VERSION]
    type = File.extname path

    comment = type == '.lua' ? '--' : '//'
    after = "#{comment} Version: #{DEFAULT_VERSION}\n\n#{before}"
  end

  file.rewind
  file.write after
  file.truncate file.pos
rescue ArgumentError => e
  if e.message == 'invalid byte sequence in UTF-8'
    encoding = Encoding::ISO_8859_1
    retry
  else
    throw
  end
ensure
  file.close
end

count = 0

Dir.glob '**/*.{lua,eel}' do |path|
  count += 1 if process_file path
end

puts "%d files modified!" % count