#lang racket/base

(require rackunit
         racket/file
         "../flac-decoder.rkt"
         "../flac-encoder.rkt")

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Tests for module flac-decoder.rkt
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Generate a small native FLAC fixture without external programs or test data.
(let* ((directory (make-temporary-file "flac-lifecycle-~a" 'directory))
       (file (build-path directory "silence.flac"))
       (format (hasheq 'sample-rate 44100 'channels 2 'bits-per-sample 24)))
  (dynamic-wind
    void
    (λ ()
      (let ((encoder (flac-encoder-open file (hasheq) format))
            (samples (make-bytes (* 256 2 3))))
        (flac-encoder-write encoder format samples (bytes-length samples))
        (flac-encoder-finish encoder))

      (test-case "repeated stop before reading is harmless"
        (let ((handle (flac-open file void void)))
          (check-not-exn (λ () (flac-stop handle)))
          (check-not-exn (λ () (flac-stop handle)))))

      (test-case "stop after decoder EOF is harmless"
        (let ((handle (flac-open file void void)))
          (flac-read handle)
          (check-false (flac-handle-reading handle))
          (check-not-exn (λ () (flac-stop handle)))))

      (test-case "callback failure releases the decoder and allows stop"
        (let ((handle (flac-open file void
                                 (λ (_header _samples _size)
                                   (error 'test "audio consumer failed")))))
          (check-exn #rx"audio consumer failed" (λ () (flac-read handle)))
          (check-false (flac-handle-reading handle))
          (let ((stopper (thread (λ () (flac-stop handle)))))
            (dynamic-wind
              void
              (λ () (check-not-false (sync/timeout 2 stopper)))
              (λ () (unless (thread-dead? stopper) (kill-thread stopper)))))))

      (test-case "invalid FLAC data reports failure and remains stoppable"
        (let ((broken (build-path directory "broken.flac")))
          (display-to-file #"fLaC" broken)
          (let ((handle (flac-open broken void void)))
            (check-exn #rx"Could not decode FLAC frame"
                       (λ () (flac-read handle)))
            (check-false (flac-handle-reading handle))
            (check-not-exn (λ () (flac-stop handle))))))

      (test-case "a stop request waits for active decoder cleanup"
        (letrec ((entered (make-semaphore 0))
               (handle
                (flac-open file void
                           (λ (_header _samples _size)
                             (semaphore-post entered)
                             (let loop ()
                               (unless (flac-handle-stop-reading handle)
                                 (sleep 0.001)
                                 (loop))))))
               (reader (thread (λ () (flac-read handle)))))
          (dynamic-wind
            void
            (λ ()
              (check-not-false (sync/timeout 2 entered))
              (flac-stop handle)
              (check-false (flac-handle-reading handle))
              (check-not-false (sync/timeout 2 reader))
              (check-not-exn (λ () (flac-stop handle))))
            (λ () (unless (thread-dead? reader) (kill-thread reader)))))))
    (λ () (delete-directory/files directory))))