<!doctype html>
<html>
  <head>
    <title>Test statechange event</title>
    <script src="../resources/js-test.js"></script>
    <script src="resources/audio-testing.js"/>
    <script src="resources/compatibility.js"></script>
  </head>

  <body>
    <script>
      description("Test statechange event is properly signaled")

      window.jsTestIsAsync = true;

      var secondsToRender = 2;
      var sampleRate = 48000;

      var stateChangeCount = 0;
      var context;
      var contextState;

      function checkStateChange (e) {
        contextState = e.currentTarget.state;

        switch (stateChangeCount) {
        case 0:
          shouldBeEqualToString("contextState", "running");
          break;
        case 1:
          shouldBeEqualToString("contextState", "closed");
          break;
        default:
          testFailed("Expected only two state changes but got " + stateChangeCount);
        }
        ++stateChangeCount;
      }

      function finalCheck() {
        // Final check that we got the right number of state changes and the correct final state.
        shouldBeEqualToNumber("stateChangeCount", 2);
        shouldBeEqualToString("context.state", "closed");
        finishJSTest();
      }

      function runTest() {
        // Create an offline context with a source passing through a convolver.  The convolver is
        // just to waste some time.
        context = new OfflineAudioContext(1, secondsToRender * sampleRate, sampleRate);
        var buffer = createImpulseBuffer(context, sampleRate);
        var source = context.createBufferSource();
        var conv = context.createConvolver();

        source.buffer = buffer;
        conv.normalize = false;
        conv.buffer = buffer;

        source.connect(conv);
        conv.connect(context.destination);

        source.start();

        context.onstatechange = checkStateChange;

        context.startRendering().then(function () {
          testPassed("context finished rendering")
        });

        // Don't want to set an oncomplete for the context and don't want to use the promise because
        // the order of the state change event and resolving the promise is not specified.  Thus,
        // just wait for a bit and then finish the test.  We assume the offline context runs faster
        // than realtime.
        setTimeout(finalCheck, secondsToRender * 1000);
      }

      runTest();
    </script>
  </body>
</html>