Add Locale Strings

add_locale_string.rb

#!/usr/bin/env ruby
require 'yaml'

#
# Consts
#

PROG_VERSION = '1.0.0'
PROG_NAME = 'add_locale_string'

#
# Lesser Variables
#

@error_messages = {
  key: "Error: invalid key '#{ARGV[1]}' supplied. Keys may contain only lowercase letters and periods, and must begin and end with a letter."
}

#
# Methods
#

# Recursively merge hashes.
#
# This operates in a different manner to the normal Hash.merge method!
#
# 1. It is recursive, unlike Hash.merge.
# 2. Data in the existing hash is preferentially saved in all cases.
#
# @param [Hash] hash - Hash to merge into this.
# @return [Hash] self

class Hash
  def recursive_merge(hash)
    self.merge(hash) do |key, self_val, hash_val|
      self_val.is_a?(Hash) ? self_val.recursive_merge(hash_val) : self_val
    end
  end
end

# Return list of files in given directory.
#
# @return [Array] - List of files.

class Dir
  def self.files(dir, regex = //)
    files = Dir.entries(dir).select do |file|
      !File.directory?(file) && file =~ regex
    end
  end
end

# Print application help message, and exit the application.

def print_help
  puts "\n#{PROG_NAME}, version #{PROG_VERSION}"
  puts "\n#{PROG_NAME} inserts a new locale English string into project YAML language files. A placeholder value will be inserted into non-English files."
  puts "\nIn all cases existing values will be preserved. This tool will _not_ overwrite any existing values."
  puts "\nusage:\t#{PROG_NAME} [folder] [key] [string]"
  puts "\t#{PROG_NAME} controller happy.lego.man 'Everything is awesome!'"
  exit
end

# Print error message, and exit the application
#
# @param [Symbol] error - Error to print.

def print_error(error)
  puts @error_messages[error] || 'Generic error oh my.'
  print_help
end

# Recursively convert an array in to a hash with a value at the end.
#
# @see http://stackoverflow.com/a/5095149/1433400
# @param [Array] keys - Array of keys to convert.
# @param [String] message - Message to insert at the end.
# @return [Hash] - Recursively nested hash.

def locale_hash(keys, message)
  keys.split('.').reverse.inject(message) do |sum, element|
    { element => sum }
  end
end

# Return locale message for given file.
#
# This script only adds messages to English files. Placeholder values are
# inserted for other languages.
#
# @param [String] file - Filename to open.
# @return [String] - Locale string.

def locale_message(file)
  return @message_string if file == 'en.yml'
  '[NYI] TRANSLATION MISSING'
end

#
# Validations
#
# 1. Test for empty arguments.
# 2. Validate folder name against whitelist.
# 3. Test that key matches regex. See: https://regex101.com/r/fA1vN2/1
#

print_help if ARGV.empty? || ARGV[0] == 'help'
# print_error :folder if !LOCALE_FOLDERS.include? ARGV[0]
print_error :key if ARGV[1] !~ /\A[a-z][a-z.]+[a-z]\z/

#
# Assignations
#

@target_folder = ARGV.shift
@yaml_key = ARGV.shift
@message_string = ARGV.join(' ')

#
# Happy Goodness
#

# FIXME: Change @target_folder to some sort of whitelisted app path.
Dir.chdir @target_folder

Dir.files('.', /\A.+\.yml\z/).each do |file_name|
  # 1. Generate hashes to merge.
  new_locale_data = locale_hash @yaml_key, locale_message(file_name)
  locale_data = YAML.load_file(file_name)

  if locale_data
    # 2a. Read file and recursively merge it's contents with the new string.
    # 2b. Existing strings will be preserved in all cases.
    locale_data = locale_data.recursive_merge new_locale_data
    # locale_data = locale_data.merge new_locale_data
    # 3. Write to file.
    File.open(file_name, 'w') { |file| file.write locale_data.to_yaml }
  end
end