<script>
    function log(msg)
    {
//        alert(msg);
        window.webkit.messageHandlers.testHandler.postMessage(msg);
    }

    function shouldBeType(_a, _type)
    {
        var exception;
        var _av;
        try {
            _av = eval(_a);
        } catch (e) {
            exception = e;
        }

        var _typev = eval(_type);
        if (_av instanceof _typev) {
            return true;
        } else {
            return false;
        }
    }

    // Values that are used to infer the type of a given primitive type.
    var testValues = [
        undefined,
        null,
        5, // Int
        0,
        1,
        false,
        true,
        5.5, // Double
        "Hello,World!",
        ""
    ];

    // Values that are used to infer the type of a given Boolean/String type.
    var testTypeValues = [
        { item: new Boolean(true), type: "Boolean", value: true },
        { item: new Boolean(false), type: "Boolean", value: false },
        { item: new String(), type: "String", value: "" }
    ];

    indexedDB.deleteDatabase("backward_compatibility");
    var openRequest = indexedDB.open("backward_compatibility");
    openRequest.onupgradeneeded = function(event) {
        // This objectStore stores elements that we only need to check its type to determine its serialization tag.
        var objectStore = event.target.result.createObjectStore("type");
        // This objectStore stores elements that we need to check its value to determine its serialization tag.
        var objectStore = event.target.result.createObjectStore("value", { autoIncrement : true });
        // This objectStore stores elements that we need to check both its type and its value to determine its serialization tag.
        var objectStore = event.target.result.createObjectStore("typeValue", { autoIncrement : true });
    }
    openRequest.onerror = function(event) {
        log("Error: " + event.target.error.name);
    }
    openRequest.onsuccess = function(event) {
        db = event.target.result;
        storeType();
    }

    function storeType()
    {
        var transaction = db.transaction("type", "readwrite");
        transaction.onerror = function(event) {
            log("Error: " + event.target.error.name);
        }
        transaction.oncomplete = function(event) { storeValue(); }

        var objectStore = transaction.objectStore("type");
        // The key of an item is the type of its value, hence we could determine type mismatch, i.e. serialization tag reorder
        // simply by using an item's key and value.
        objectStore.add([1, 2], "Array");
        objectStore.add({ property: null }, "Object");
        objectStore.add(new Date(), "Date");
        objectStore.add(new File(["foo"], "foo.txt"), "File");
        objectStore.add(new ImageData(100, 100), "ImageData");
        objectStore.add(new Blob(["foo"]), "Blob");
        objectStore.add(new RegExp(''), "RegExp");
        objectStore.add(new ArrayBuffer(1), "ArrayBuffer");
        objectStore.add(new String(''), "String");
        objectStore.add(new Number(12), "Number");
        objectStore.add(new Set([1, 2]), "Set");
        objectStore.add(new Map(), "Map");
        // Typed arrays
        objectStore.add(new Int8Array(), "Int8Array");
        objectStore.add(new Uint8Array(), "Uint8Array");
        objectStore.add(new Uint8ClampedArray(), "Uint8ClampedArray");
        objectStore.add(new Int16Array(), "Int16Array");
        objectStore.add(new Uint16Array(), "Uint16Array");
        objectStore.add(new Int32Array(), "Int32Array");
        objectStore.add(new Uint32Array(), "Uint32Array");
        objectStore.add(new Float32Array(), "Float32Array");
        objectStore.add(new Float64Array(), "Float64Array");
    }

    function storeValue()
    {
        var transaction = db.transaction("value", "readwrite");
        transaction.onerror = function(event) {
            log("Error: " + event.target.error.name);
        }
        transaction.oncomplete = function(event) { storeTypeValue(); }

        var objectStore = transaction.objectStore("value");
        // Here we store values in the test matrix in order and read them in order to see if any mismatch happens.
        for (var i = 0; i < testValues.length; i++)
            objectStore.add(testValues[i]);
    }

    function storeTypeValue()
    {
        var transaction = db.transaction("typeValue", "readwrite");
        transaction.onerror = function(event) {
            log("Error: " + event.target.error.name);
        }
        transaction.oncomplete = function(event) { readType(); }

        var objectStore = transaction.objectStore("typeValue");
        // Here we store items in the test matrix in order and read them in order to see if any mismatches its type and value.
        for (var i = 0; i < testTypeValues.length; i++)
            objectStore.add(testTypeValues[i].item);
    }

    var result = true;
    function readType()
    {
        var objectStore = db.transaction("type").objectStore("type");
        objectStore.openCursor().onsuccess = function(event) {
            cursor = event.target.result;
            if (cursor) {
                result = result && shouldBeType("cursor.value", cursor.key);
                cursor.continue();
            } else
                readValue();
        };
    }

    function readValue()
    {
        var objectStore = db.transaction("value").objectStore("value");
        objectStore.openCursor().onsuccess = function(event) {
            cursor = event.target.result;
            if (cursor) {
                result = result && (cursor.value === testValues[cursor.key - 1]);
                cursor.continue();
            } else
                readTypeValue();
        };
    }

    function readTypeValue()
    {
        var objectStore = db.transaction("typeValue").objectStore("typeValue");
        objectStore.openCursor().onsuccess = function(event) {
            cursor = event.target.result;
            if (cursor) {
                result = result && shouldBeType("cursor.value", testTypeValues[cursor.key - 1].type) && (cursor.value == testTypeValues[cursor.key - 1].value);
                cursor.continue();
            } else {
                if (result)
                    log("Pass");
                else
                    log("Fail");
            }
        };
    }
</script>