<!DOCTYPE html>
<html>
<head>
<script src="../../http/tests/inspector/resources/inspector-test.js"></script>
<script>
function load() {
    window.context = document.body.appendChild(document.createElement("canvas")).getContext("2d");

    runTest();
}

function changeSize(width, height) {
    window.context.canvas.width = width;
    window.context.canvas.height = height;

    // Force the creation of the image buffer, which is used to determine memory cost.
    window.context.canvas.toDataURL();
}

function test() {
    let suite = InspectorTest.createAsyncSuite("Canvas.memory");

    suite.addTestCase({
        name: "Canvas.memory.memoryCost",
        description: "Check that memory cost is sent with the canvas when able.",
        test(resolve, reject) {
            // NOTE: the memory cost of a canvas will not be retrievable until an operation is
            // performed on that canvas that requires the image buffer.  A blank canvas that was
            // just created will not have a buffer, so its memory cost will be 0/NaN.

            let canvases = WI.canvasManager.canvases.filter((canvas) => canvas.contextType === WI.Canvas.ContextType.Canvas2D);
            if (!canvases.length) {
                reject("Missing 2D canvas.");
                return;
            }

            InspectorTest.assert(canvases.length === 1, "There should only be one canvas-2d.");

            InspectorTest.log(`Memory cost of canvas is ${canvases[0].memoryCost}.`);
            resolve();
        }
    });

    suite.addTestCase({
        name: "Canvas.memory.canvasMemoryChanged",
        description: "Check that memory cost is updated when the backend value changes.",
        test(resolve, reject) {
            let canvases = WI.canvasManager.canvases.filter((canvas) => canvas.contextType === WI.Canvas.ContextType.Canvas2D);
            if (!canvases.length) {
                reject("Missing 2D canvas.");
                return;
            }

            InspectorTest.assert(canvases.length === 1, "There should only be one canvas-2d.");

            canvases[0].awaitEvent(WI.Canvas.Event.MemoryChanged)
            .then((event) => {
                InspectorTest.log(`Memory cost of canvas updated to ${event.target.memoryCost}.`);
            })
            .then(resolve, reject);

            const width = 200;
            const height = 200;
            InspectorTest.log(`Change size of canvas to ${width}x${height}.`);
            InspectorTest.evaluateInPage(`changeSize(${width}, ${height})`);
        }
    });

    suite.runTestCasesAndFinish();
}
</script>
</head>
<body onload="load()">
    <p>Test that CanvasManager tracks canvas memory costs and is notified of changes.</p>
</body>
</html>