<html>
    <title>Test media source replacement</title>
    <body>

    <p>Test that media keeps playing when the source element is replaced.</p>

    <script src=video-test.js></script>
    <script src=media-file.js></script>
    <script src=../resources/gc.js></script>
    <script>
        var timeupdateEventCount = 0;
        var skippedCount = 0;
        var sourceReplaced = false;

        function swapAudio() {
            v = document.getElementsByTagName('audio')[0];
            v.removeChild(v.childNodes[0]);
            var s = document.createElement('source');
            s.src = findMediaFile("audio", "content/test");
            v.appendChild(s);
        }

        function errorListener(event)
        {
             logResult(false, "Caught 'error' event, audio.error.code = " + this.error.code);
             endTest();
        }

        function canplaythroughListener(event)
        {
             consoleWrite("EVENT(canplaythrough)");
             testElement = this;
             testExpected("testElement.currentTime", 0);
             this.play();
        }

        function playingListener(event)
        {
             consoleWrite("EVENT(playing)");
        }

        function timeupdateListener(event)
        {
            ++timeupdateEventCount;

            if (timeupdateEventCount-skippedCount == 1) {
                // First time update after source replacement should be 0.
                // We allow one late time update to come in from the previous
                // source element. This was done to help the cr-linux test
                // pass, and does not necessarily indicate a problem.
                if (sourceReplaced) {
                    if (skippedCount >= 1 || this.currentTime == 0) {
                        testElement = this;
                        testExpected("testElement.currentTime", 0);
                    } else {
                        // The time is not 0 as expected. Hope this is a
                        // late update from the previous source.
                        ++skippedCount;
                    }
                }
            } else if (timeupdateEventCount-skippedCount >= 2) {
                // We wait 2 timeupdate events so we are sure the media engine
                // is playing the media, and make sure time is advancing.
                testElement = this;
                testExpected("testElement.currentTime", 0, '>');
                if (!sourceReplaced) {
                    consoleWrite("Replacing the media's source element:");
                    sourceReplaced = true;
                    timeupdateEventCount = 0;
                    skippedCount = 0;
                    // The ports are not consistent in regards to whether
                    // the canplaythrough and playing events are triggered
                    // a second time, so stop listening for them. This was
                    // done to help the cr-linux test pass, and does not
                    // necessarily indicate a problem.
                    this.removeEventListener('playing', playingListener);
                    this.removeEventListener('canplaythrough', canplaythroughListener);
                    swapAudio();
                } else {
                    this.removeEventListener('timeupdate', timeupdateListener);
                    this.pause();
                    endTest();
                }
            }
        }

        function testAudioElement(count)
        {
            timeupdateEventCount = 0;
            skippedCount = 0;
            var audioElement = document.getElementsByTagName('audio')[count];
            //audioElement.removeChild(audioElement.childNodes[0]);
            audioElement.addEventListener('error', errorListener);
            audioElement.addEventListener('canplaythrough', canplaythroughListener);
            audioElement.addEventListener('timeupdate', timeupdateListener);
            audioElement.addEventListener('playing', playingListener);

            var s = document.createElement('source');
            s.src = findMediaFile("audio", "content/silence");
            audioElement.appendChild(s);

        }

        document.write("<audio controls></audio>");
        testAudioElement(0);
        gc();
        gc();
    </script>

    </body>
</html>