(use test)
(use base64)

(test-group
 "encoding"
 (test "encode string of length 0"
       ""
       (base64-encode ""))
 (test "encode string of length 1"
       "YQ=="
       (base64-encode "a"))
 (test "encode string of length 2"
       "YWI="
       (base64-encode "ab"))
 (test "encode string of length 3"
       "YWJj"
       (base64-encode "abc"))
 (test "encode string of length 5*3"
       "YWJjZGVmZ2hpamtsbW5v"
       (base64-encode "abcdefghijklmno"))
 (test "encode string of length 5*3+1"
       "YWJjZGVmZ2hpamtsbW5vcA=="
       (base64-encode "abcdefghijklmnop"))
 (test "encode string of length 5*3+2"
       "YWJjZGVmZ2hpamtsbW5vcHE="
       (base64-encode "abcdefghijklmnopq"))
 (test "encode string of length 6*3"
       "YWJjZGVmZ2hpamtsbW5vcHFy"
       (base64-encode "abcdefghijklmnopqr"))
 (test "encode binary string"
       "3q2+78r+sAs="
       (base64-encode "\xde\xad\xbe\xef\xca\xfe\xb0\x0b")))

;; to avoid measuring time in test (doesn't really matter)
(define large-string (make-string 10000001 #\a))
(define large-encoded-string (base64-encode large-string))
(define large-invalid-string (make-string 10000001 #\%))

(test-group
 "decoding"
 (test "decode empty string -> empty"
       ""
       (base64-decode ""))
 (test "decode string Y -> empty"
       ""
       (base64-decode "Y"))
 (test "decode string YW -> a"
       "a"
       (base64-decode "YW"))
 (test "decode string YW= -> a"
       "a"
       (base64-decode "YW="))
 (test "decode string YW== -> a"
       "a"
       (base64-decode "YW==")) 
 (test "decode string YWJ => ab"
       "ab"
       (base64-decode "YWJ"))
 (test "decode string YWJ= -> ab"
       "ab"
       (base64-decode "YWJ="))
 (test "decode string YWJj -> abc"
       "abc"
       (base64-decode "YWJj"))
 (test "decode string YW%J^jZ -> abc"
       "abc"
       (base64-decode "YW%J^jZ"))
 (test "decode skips invalid chars"
       "abcdefghijklmnop"
       (base64-decode "YWJjZG(VmZ#2hp@amtsb%&W5v**cA======"))
 (test "decode binary string"
       "\xde\xad\xbe\xef\xca\xfe\xb0\x0b"
       (base64-decode "3q2+78r+sAs="))
 (test "decode large string"
       large-string
       (base64-decode large-encoded-string))
 (test "decode large string of invalid chars"
       ""
       (base64-decode large-invalid-string))
 )

;; Not on a 64-bit machine! :)
;; (test-error "encode string of length 16,000,000 signals an error"
;;             (base64-encode (make-string 16000000)))