#!/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby
#
# generate_cask_token
#
# todo:
#
# remove Ruby 2.0 dependency and change shebang line
#
# detect Cask files which differ only by the placement of hyphens.
#
# merge entirely into "brew cask create" command
#

###
### dependencies
###

require "pathname"
require "open3"

begin
  # not available by default
  require "active_support/inflector"
rescue LoadError
end

###
### configurable constants
###

EXPANDED_SYMBOLS = {
                     "+" => "plus",
                     "@" => "at",
                   }.freeze

CASK_FILE_EXTENSION = ".rb".freeze

# Hardcode App names that cannot be transformed automatically.
# Example: in "x48.app", "x48" is not a version number.
# The value in the hash should be a valid Cask token.
APP_EXCEPTION_PATS = {
                       # looks like a trailing version, but is not.
                       %r{\Aiterm\Z}i               => "iterm2",
                       %r{\Aiterm2\Z}i              => "iterm2",
                       %r{\Apgadmin3\Z}i            => "pgadmin3",
                       %r{\Ax48\Z}i                 => "x48",
                       %r{\Avitamin-r[\s\d\.]*\Z}i  => "vitamin-r",
                       %r{\Aimagealpha\Z}i          => "imagealpha",
                       # upstream is in the midst of changing branding
                       %r{\Abitcoin-?qt\Z}i         => "bitcoin-core",
                       # "mac" cannot be separated from the name because it is in an English phrase
                       %r{\Aplayonmac\Z}i           => "playonmac",
                       %r{\Acleanmymac[\s\d\.]*\Z}i => "cleanmymac",
                       # arguably we should not have kept these two exceptions
                       %r{\Akismac\Z}i              => "kismac",
                       %r{\Avoicemac\Z}i            => "voicemac",
                     }.freeze

# Preserve trailing patterns on App names that could be mistaken
# for version numbers, etc
PRESERVE_TRAILING_PATS = [
                           %r{id3}i,
                           %r{mp3}i,
                           %r{3[\s-]*d}i,
                           %r{diff3}i,
                           %r{\A[^\d]+\+\Z}i,
                         ].freeze

# The code that employs these patterns against App names
# - hacks a \b (word-break) between CamelCase and snake_case transitions
# - anchors the pattern to end-of-string
# - applies the patterns repeatedly until there is no match
REMOVE_TRAILING_PATS = [
                         # spaces
                         %r{\s+}i,

                         # generic terms
                         %r{\bapp}i,
                         %r{\b(?:quick[\s-]*)?launcher}i,

                         # "mac", "for mac", "for OS X", "macOS", "for macOS".
                         %r{\b(?:for)?[\s-]*mac(?:intosh|OS)?}i,
                         %r{\b(?:for)?[\s-]*os[\s-]*x}i,

                         # hardware designations such as "for x86", "32-bit", "ppc"
                         %r{(?:\bfor\s*)?x.?86}i,
                         %r{(?:\bfor\s*)?\bppc}i,
                         %r{(?:\bfor\s*)?\d+.?bits?}i,

                         # frameworks
                         %r{\b(?:for)?[\s-]*(?:oracle|apple|sun)*[\s-]*(?:jvm|java|jre)}i,
                         %r{\bgtk}i,
                         %r{\bqt}i,
                         %r{\bwx}i,
                         %r{\bcocoa}i,

                         # localizations
                         %r{en\s*-\s*us}i,

                         # version numbers
                         %r{[^a-z0-9]+}i,
                         %r{\b(?:version|alpha|beta|gamma|release|release.?candidate)(?:[\s\.\d-]*\d[\s\.\d-]*)?}i,
                         %r{\b(?:v|ver|vsn|r|rc)[\s\.\d-]*\d[\s\.\d-]*}i,
                         %r{\d+(?:[a-z\.]\d+)*}i,
                         %r{\b\d+\s*[a-z]}i,
                         %r{\d+\s*[a-c]}i, # constrained to a-c b/c of false positives
                       ].freeze

# Patterns which are permitted (undisturbed) following an interior version number
AFTER_INTERIOR_VERSION_PATS = [
                                %r{ce}i,
                                %r{pro}i,
                                %r{professional}i,
                                %r{client}i,
                                %r{server}i,
                                %r{host}i,
                                %r{viewer}i,
                                %r{launcher}i,
                                %r{installer}i,
                              ].freeze

###
### classes
###

class AppName < String
  def self.remove_trailing_pat
    @@remove_trailing_pat ||= %r{(?<=.)(?:#{REMOVE_TRAILING_PATS.join('|')})\Z}i
  end

  def self.preserve_trailing_pat
    @@preserve_trailing_pat ||= %r{(?:#{PRESERVE_TRAILING_PATS.join('|')})\Z}i
  end

  def self.after_interior_version_pat
    @@after_interior_version_pat ||= %r{(?:#{AFTER_INTERIOR_VERSION_PATS.join('|')})}i
  end

  def english_from_app_bundle
    return self if ascii_only?
    return self unless File.exist?(self)

    # check Info.plist CFBundleDisplayName
    bundle_name = Open3.popen3(*%w[
                                  /usr/libexec/PlistBuddy -c
                                ],
                               "Print CFBundleDisplayName",
                               Pathname.new(self).join("Contents", "Info.plist").to_s) do |_stdin, stdout, _stderr|
      begin
        stdout.gets.force_encoding("UTF-8").chomp
      rescue
      end
    end
    return AppName.new(bundle_name) if bundle_name && bundle_name.ascii_only?

    # check Info.plist CFBundleName
    bundle_name = Open3.popen3(*%w[
                                  /usr/libexec/PlistBuddy -c
                                ],
                               "Print CFBundleName",
                               Pathname.new(self).join("Contents", "Info.plist").to_s) do |_stdin, stdout, _stderr|
      begin
        stdout.gets.force_encoding("UTF-8").chomp
      rescue
      end
    end
    return AppName.new(bundle_name) if bundle_name && bundle_name.ascii_only?

    # check localization strings
    local_strings_file = Pathname.new(self).join("Contents", "Resources", "en.lproj", "InfoPlist.strings")
    local_strings_file = Pathname.new(self).join("Contents", "Resources", "English.lproj", "InfoPlist.strings") unless local_strings_file.exist?
    if local_strings_file.exist?
      bundle_name = File.open(local_strings_file, "r:UTF-16LE:UTF-8") do |fh|
        %r{\ACFBundle(?:Display)?Name\s*=\s*"(.*)";\Z}.match(fh.readlines.grep(%r{^CFBundle(?:Display)?Name\s*=\s*}).first) do |match|
          match.captures.first
        end
      end
      return AppName.new(bundle_name) if bundle_name && bundle_name.ascii_only?
    end

    # check Info.plist CFBundleExecutable
    bundle_name = Open3.popen3(*%w[
                                  /usr/libexec/PlistBuddy -c
                                ],
                               "Print CFBundleExecutable",
                               Pathname.new(self).join("Contents", "Info.plist").to_s) do |_stdin, stdout, _stderr|
      begin
        stdout.gets.force_encoding("UTF-8").chomp
      rescue
      end
    end
    return AppName.new(bundle_name) if bundle_name && bundle_name.ascii_only?

    self
  end

  def basename
    if Pathname.new(self).exist?
      AppName.new(Pathname.new(self).basename.to_s)
    else
      self
    end
  end

  def remove_extension
    sub(%r{\.app\Z}i, "")
  end

  def decompose_to_ascii
    # crudely (and incorrectly) decompose extended latin characters to ASCII
    return self if ascii_only?
    return self unless respond_to?(:mb_chars)
    AppName.new(mb_chars.normalize(:kd).each_char.select(&:ascii_only?).join)
  end

  def hardcoded_exception
    APP_EXCEPTION_PATS.each do |regexp, exception|
      return AppName.new(exception) if regexp.match(self)
    end
    nil
  end

  def insert_vertical_tabs_for_camel_case
    app_name = AppName.new(self)
    if app_name.sub!(%r{(#{self.class.preserve_trailing_pat})\Z}i, "")
      trailing = Regexp.last_match(1)
    end
    app_name.gsub!(%r{([^A-Z])([A-Z])}, "\\1\v\\2")
    app_name.sub!(%r{\Z}, trailing) if trailing
    app_name
  end

  def insert_vertical_tabs_for_snake_case
    gsub(%r{_}, "\v")
  end

  def clean_up_vertical_tabs
    gsub(%r{\v}, "")
  end

  def remove_interior_versions!
    # done separately from REMOVE_TRAILING_PATS because this
    # requires a substitution with a backreference
    sub!(%r{(?<=.)[\.\d]+(#{self.class.after_interior_version_pat})\Z}i, '\1')
    sub!(%r{(?<=.)[\s\.\d-]*\d[\s\.\d-]*(#{self.class.after_interior_version_pat})\Z}i, '-\1')
  end

  def remove_trailing_strings_and_versions
    app_name = insert_vertical_tabs_for_camel_case
               .insert_vertical_tabs_for_snake_case
    while self.class.remove_trailing_pat.match(app_name) &&
          !self.class.preserve_trailing_pat.match(app_name)
      app_name.sub!(self.class.remove_trailing_pat, "")
    end
    app_name.remove_interior_versions!
    app_name.clean_up_vertical_tabs
  end

  def simplified
    return @simplified if @simplified
    @simplified = english_from_app_bundle
                  .basename
                  .decompose_to_ascii
                  .remove_extension
    @simplified = @simplified.hardcoded_exception || @simplified.remove_trailing_strings_and_versions
    @simplified
  end
end

class CaskFileName < String
  def spaces_to_hyphens
    gsub(%r{ +}, "-")
  end

  def delete_invalid_chars
    gsub(%r{[^a-z0-9-]+}, "")
  end

  def collapse_multiple_hyphens
    gsub(%r{--+}, "-")
  end

  def delete_leading_hyphens
    gsub(%r{^--+}, "")
  end

  def delete_hyphens_before_numbers
    gsub(%r{-([0-9])}, '\1')
  end

  def spell_out_symbols
    cask_file_name = self
    EXPANDED_SYMBOLS.each do |k, v|
      cask_file_name.gsub!(k, " #{v} ")
    end
    cask_file_name.sub(%r{ +\Z}, "")
  end

  def add_extension
    sub(%r{(?:#{escaped_cask_file_extension})?\Z}i, CASK_FILE_EXTENSION)
  end

  def remove_extension
    sub(%r{#{escaped_cask_file_extension}\Z}i, "")
  end

  def from_simplified_app_name
    return @from_simplified_app_name if @from_simplified_app_name
    @from_simplified_app_name = if APP_EXCEPTION_PATS.rassoc(remove_extension)
                                  remove_extension
                                else
                                  remove_extension
                                    .downcase
                                    .spell_out_symbols
                                    .spaces_to_hyphens
                                    .delete_invalid_chars
                                    .collapse_multiple_hyphens
                                    .delete_leading_hyphens
                                    .delete_hyphens_before_numbers
    end
    raise "Could not determine Simplified App name" if @from_simplified_app_name.empty?
    @from_simplified_app_name.add_extension
  end
end

###
### methods
###

def project_root
  Dir.chdir File.dirname(File.expand_path(__FILE__))
  @git_root ||= Open3.popen3(*%w[
                                git rev-parse --show-toplevel
                              ]) do |_stdin, stdout, _stderr|
    begin
      Pathname.new(stdout.gets.chomp)
    rescue
      raise "could not find project root"
    end
  end
  raise "could not find project root" unless @git_root.exist?
  @git_root
end

def escaped_cask_file_extension
  @escaped_cask_file_extension ||= Regexp.escape(CASK_FILE_EXTENSION)
end

def simplified_app_name
  @simplified_app_name ||= AppName.new(ARGV.first.dup.force_encoding("UTF-8")).simplified
end

def cask_file_name
  @cask_file_name ||= CaskFileName.new(simplified_app_name).from_simplified_app_name
end

def cask_token
  @cask_token ||= cask_file_name.remove_extension
end

def warnings
  return @warnings if @warnings
  @warnings = []
  unless APP_EXCEPTION_PATS.rassoc(cask_token)
    if %r{\d} =~ cask_token
      @warnings.push "WARNING: '#{cask_token}' contains digits. Digits which are version numbers should be removed."
    end
  end
  filename = project_root.join("Casks", cask_file_name)
  if filename.exist?
    @warnings.push "WARNING: the file '#{filename}' already exists. Prepend the vendor name if this is not a duplicate."
  end
  @warnings
end

def report
  puts "Proposed Simplified App name: #{simplified_app_name}" if $debug
  puts "Proposed token:               #{cask_token}"
  puts "Proposed file name:           #{cask_file_name}"
  puts "Cask Header Line:             cask '#{cask_token}' do"
  unless warnings.empty?
    $stderr.puts "\n"
    $stderr.puts warnings
    $stderr.puts "\n"
    exit 1
  end
end

###
### main
###

usage = <<-EOS
Usage: generate_cask_token [ -debug ] <application.app>

Given an Application name or a path to an Application, propose a
Cask token, filename, and header line.

With -debug, also provide the internal "Simplified App Name".

EOS

if ARGV.first =~ %r{^-+h(elp)?$}i
  puts usage
  exit 0
end

if ARGV.first =~ %r{^-+debug?$}i
  $debug = 1
  ARGV.shift
end

unless ARGV.length == 1
  puts usage
  exit 1
end

report