module Xlsxrb::Ooxml::Crypto

# File lib/xlsxrb/ooxml/crypto.rb, line 27
def decrypt(cfb_data, password)
  raise Xlsxrb::EncryptedFileError, "Password is required to decrypt this file" if password.nil? || password.to_s.empty?

  reader = Cfb::Reader.new(cfb_data)
  encryption_info = reader.read_stream("EncryptionInfo")
  encrypted_package = reader.read_stream("EncryptedPackage")

  raise Xlsxrb::DecryptionError, "Missing EncryptionInfo or EncryptedPackage stream" if encryption_info.nil? || encrypted_package.nil?

  major, minor = encryption_info[0, 4].unpack("vv")
  if major == 4 && minor == 4
    Agile.decrypt(encryption_info, encrypted_package, password)
  elsif minor == 2
    Standard.decrypt(encryption_info, encrypted_package, password)
  else
    raise Xlsxrb::DecryptionError, "Unsupported encryption version #{major}.#{minor}"
  end
end

# File lib/xlsxrb/ooxml/crypto.rb, line 47
def encrypt(plain_zip_data, password, mode: :standard)
  return plain_zip_data if password.nil? || password.to_s.empty?

  streams = if mode == :agile
              Agile.encrypt(plain_zip_data, password)
            else
              Standard.encrypt(plain_zip_data, password)
            end
  Cfb::Writer.write(streams)
end

# File lib/xlsxrb/ooxml/crypto.rb, line 15
def encrypted?(data)
  return false unless Cfb::Reader.cfb?(data)

  begin
    reader = Cfb::Reader.new(data)
    reader.stream_names.any? { |n| n.casecmp?("EncryptionInfo") }
  rescue StandardError
    false
  end
end