# -*- encoding: utf-8; frozen_string_literal: true -*-
#
#--
# This file is part of HexaPDF.
#
# HexaPDF - A Versatile PDF Creation and Manipulation Library For Ruby
# Copyright (C) 2014-2024 Thomas Leitner
#
# HexaPDF is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License version 3 as
# published by the Free Software Foundation with the addition of the
# following permission added to Section 15 as permitted in Section 7(a):
# FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
# THOMAS LEITNER, THOMAS LEITNER DISCLAIMS THE WARRANTY OF NON
# INFRINGEMENT OF THIRD PARTY RIGHTS.
#
# HexaPDF is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
# License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with HexaPDF. If not, see <http://www.gnu.org/licenses/>.
#
# The interactive user interfaces in modified source and object code
# versions of HexaPDF must display Appropriate Legal Notices, as required
# under Section 5 of the GNU Affero General Public License version 3.
#
# In accordance with Section 7(b) of the GNU Affero General Public
# License, a covered work must retain the producer line in every PDF that
# is created or manipulated using HexaPDF.
#
# If the GNU Affero General Public License doesn't fit your need,
# commercial licenses are available at <https://gettalong.at/hexapdf/>.
#++

require 'hexapdf/font/encoding'
require 'hexapdf/error'
require 'strscan'

module HexaPDF
  module Font
    module Type1

      # Parses files in the PFB file format.
      #
      # Note that this implementation isn't a full PFB parser. It is currently just used for
      # extracting the font encoding.
      class PFBParser

        # :call-seq:
        #   PFBParser.encoding(data)       -> encoding
        #
        # Parses the PFB data given as string and returns the found Encoding.
        def self.encoding(data)
          enc = Encoding::Base.new
          ss = StringScanner.new(data)
          if ss.skip_until(/\/Encoding\s+\d+\s+array.+?(?=\bdup\b)/m)
            while ss.skip(/dup\s+(\d+)\s+\/(\w+)\s+put\s+/)
              enc.code_to_name[ss[1].to_i] = ss[2].intern
            end
          elsif ss.skip_until(/\/Encoding\s+StandardEncoding\s+def/)
            enc = Encoding.for_name(:StandardEncoding)
          else
            raise HexaPDF::Error, "Unknown Type1 encoding"
          end
          enc
        end

      end

    end
  end
end