# frozen_string_literal: true require ‘mail/utilities’ require ‘mail/parser_tools’

begin

original_verbose, $VERBOSE = $VERBOSE, nil

%%{

machine content_transfer_encoding;
alphtype int;

action encoding_s { encoding_s = p }
action encoding_e { content_transfer_encoding.encoding = chars(data, encoding_s, p-1).downcase }

# No-op actions
action comment_e { }
action comment_s { }
action phrase_e { }
action phrase_s { }
action qstr_e { }
action qstr_s { }
action param_attr_e { }
action param_attr_s { }
action param_val_e { }
action param_val_s { }
action main_type_e { }
action main_type_s { }
action sub_type_e { }
action sub_type_s { }

include rfc2045_content_transfer_encoding "rfc2045_content_transfer_encoding.rl";
main := content_transfer_encoding;

}%%

module Mail::Parsers

module ContentTransferEncodingParser
  extend Mail::ParserTools

  ContentTransferEncodingStruct = Struct.new(:encoding, :error)

  %%write data noprefix;

  def self.parse(data)
    data = data.dup.force_encoding(Encoding::ASCII_8BIT) if data.respond_to?(:force_encoding)

    content_transfer_encoding = ContentTransferEncodingStruct.new('')
    return content_transfer_encoding if Mail::Utilities.blank?(data)

    # Parser state
    encoding_s = nil

    # 5.1 Variables Used by Ragel
    p = 0
    eof = pe = data.length
    stack = []

    %%write init;
    %%write exec;

    if p != eof || cs < %%{ write first_final; }%%
      raise Mail::Field::IncompleteParseError.new(Mail::ContentTransferEncodingElement, data, p)
    end

    content_transfer_encoding
  end
end

end

ensure

$VERBOSE = original_verbose

end