class Middleman::CoreExtensions::Internationalization

def after_configuration
  # See https://github.com/svenfuchs/i18n/wiki/Fallbacks
  unless options[:no_fallbacks]
    require 'i18n/backend/fallbacks'
    ::I18n::Backend::Simple.send(:include, ::I18n::Backend::Fallbacks)
  end
  locales_file_path = options[:data]
  # Tell the file watcher to observe the :data_dir
  app.files.watch :locales,
                  path: File.join(app.root, locales_file_path),
                  only: /.*(rb|yml|yaml)$/
  # Setup data files before anything else so they are available when
  # parsing config.rb
  app.files.on_change(:locales, &method(:on_file_changed))
  @maps = {}
  @mount_at_root = options[:mount_at_root].nil? ? langs.first : options[:mount_at_root]
  configure_i18n
  logger.info "== Locales: #{langs.join(', ')} (Default #{@mount_at_root})"
end

def build_resource(path, source_path, page_id, lang)
  old_locale = ::I18n.locale
  ::I18n.locale = lang
  localized_page_id = ::I18n.t("paths.#{page_id}", default: page_id, fallback: [])
  partially_localized_path = ''
  File.dirname(path).split('/').each do |path_sub|
    next if path_sub == ''
    partially_localized_path = "#{partially_localized_path}/#{(::I18n.t("paths.#{path_sub}", default: path_sub).to_s)}"
  end
  path = "#{partially_localized_path}/#{File.basename(path)}"
  prefix = if (options[:mount_at_root] == lang) || (options[:mount_at_root].nil? && langs[0] == lang)
    '/'
  else
    replacement = options[:lang_map].fetch(lang, lang)
    options[:path].sub(':locale', replacement.to_s)
  end
  # path needs to be changed if file has a localizable extension. (options[mount_at_root] == lang)
  path = ::Middleman::Util.normalize_path(
    File.join(prefix, path.sub(page_id, localized_page_id))
  )
  path = path.sub(options[:templates_dir] + '/', '')
  ::I18n.locale = old_locale
  LocalizedPageDescriptor.new(path, source_path, lang)
end

def configure_i18n
  ::I18n.load_path |= app.files.by_type(:locales).files.map { |p| p[:full_path].to_s }
  ::I18n.reload!
  ::I18n.default_locale = @mount_at_root
  # Reset fallbacks to fall back to our new default
  ::I18n.fallbacks = ::I18n::Locale::Fallbacks.new if ::I18n.respond_to?(:fallbacks)
end

def initialize(*)
  super
  require 'i18n'
  # Don't fail on invalid locale, that's not what our current
  # users expect.
  ::I18n.enforce_available_locales = false
  # This is for making the tests work - since the tests
  # don't completely reload middleman, I18n.load_path can get
  # polluted with paths from other test app directories that don't
  # exist anymore.
  app.after_configuration_eval do
    ::I18n.load_path.delete_if { |path| path =~ %r{tmp/aruba} }
    ::I18n.reload!
  end if ENV['TEST']
end

def known_languages
  if options[:langs]
    Array(options[:langs]).map(&:to_sym)
  else
    known_langs = app.files.by_type(:locales).files.select do |p|
      p[:relative_path].to_s.split(File::SEPARATOR).length == 1
    end
    known_langs.map do |p|
      File.basename(p[:relative_path].to_s).sub(/\.ya?ml$/, '').sub(/\.rb$/, '')
    end.sort.map(&:to_sym)
  end
end

def langs
  @langs ||= known_languages
end

def localized_path(path, lang)
  lookup_path = path.dup
  lookup_path << app.config[:index_file] if lookup_path.end_with?('/')
  @lookup[lookup_path] && @lookup[lookup_path][lang]
end

def locate_partial(partial_name, try_static=false)
  locals_dir = extensions[:i18n].options[:templates_dir]
  # Try /localizable
  partials_path = File.join(locals_dir, partial_name)
  lang_suffix = ::I18n.locale
  extname = File.extname(partial_name)
  maybe_static = extname.length > 0
  suffixed_partial_name = if maybe_static
    partial_name.sub(extname, ".#{lang_suffix}#{extname}")
  else
    "#{partial_name}.#{lang_suffix}"
  end
  if lang_suffix
    super(suffixed_partial_name, maybe_static) ||
      super(File.join(locals_dir, suffixed_partial_name), maybe_static) ||
      super(partials_path, try_static) ||
      super
  else
    super(partials_path, try_static) ||
      super
  end
end

def manipulate_resource_list(resources)
  new_resources = []
  file_extension_resources = resources.select do |resource|
    parse_locale_extension(resource.path)
  end
  localizable_folder_resources = resources.select do |resource|
    !file_extension_resources.include?(resource) && File.fnmatch?(File.join(options[:templates_dir], '**'), resource.path)
  end
  # If it's a "localizable template"
  localizable_folder_resources.each do |resource|
    page_id = File.basename(resource.path, File.extname(resource.path))
    langs.each do |lang|
      # Remove folder name
      path = resource.path.sub(options[:templates_dir], '')
      new_resources << build_resource(path, resource.path, page_id, lang)
    end
    resource.ignore!
    # This is for backwards compatibility with the old provides_metadata-based code
    # that used to be in this extension, but I don't know how much sense it makes.
    # next if resource.options[:lang]
    # $stderr.puts "Defaulting #{resource.path} to #{@mount_at_root}"
    # resource.add_metadata options: { lang: @mount_at_root }, locals: { lang: @mount_at_root }
  end
  # If it uses file extension localization
  file_extension_resources.each do |resource|
    result = parse_locale_extension(resource.path)
    ext_lang, path, page_id = result
    new_resources << build_resource(path, resource.path, page_id, ext_lang)
    resource.ignore!
  end
  @lookup = new_resources.each_with_object({}) do |desc, sum|
    abs_path = desc.source_path.sub(options[:templates_dir], '')
    sum[abs_path] ||= {}
    sum[abs_path][desc.lang] = '/' + desc.path
  end
  resources + new_resources.map { |r| r.to_resource(app) }
end

def on_file_changed(_updated_files, _removed_files)
  @_langs = nil # Clear langs cache
  ::I18n.load_path |= app.files.by_type(:locales).files.map { |p| p[:full_path].to_s }
  ::I18n.reload!
end

def parse_locale_extension(path)
  path_bits = path.split('.')
  return nil if path_bits.size < 3
  lang = path_bits.delete_at(-2).to_sym
  return nil unless langs.include?(lang)
  path = path_bits.join('.')
  basename = File.basename(path_bits[0..-2].join('.'))
  [lang, path, basename]
end

def t(*args)
  ::I18n.t(*args)
end

def url_for(path_or_resource, options={})
  locale = options.delete(:locale) || ::I18n.locale
  opts = options.dup
  should_relativize = opts.key?(:relative) ? opts[:relative] : config[:relative_links]
  opts[:relative] = false
  href = super(path_or_resource, opts)
  final_path = if result = extensions[:i18n].localized_path(href, locale)
    result
  else
    # Should we log the missing file?
    href
  end
  opts[:relative] = should_relativize
  begin
    super(final_path, opts)
  rescue RuntimeError
    super(path_or_resource, options)
  end
end