<!DOCTYPE html>
<html>
<head>
<script src="../../../resources/js-test.js"></script>
</head>
<body>
<script>
jsTestIsAsync = true;

function testCompleted()
{
    var scriptElement = document.createElement("script")
    scriptElement.src = '../../../resources/js-test-post-async.js'
    document.body.appendChild(scriptElement);
}

function computeResolution(resolution, imgResolutionDppx)
{
    if (!resolution)
        return;
    var fromImage = /from-image/.test(resolution);
    var snap = /snap/.test(resolution);
    var explicit = /(-?\d*(\.\d+)?)(dp(px|i|cm))/.exec(resolution);
    var value = explicit && explicit[1] * 1;
    var unit = explicit && explicit[3];
    var dppx = 1;
    if (!unit && !fromImage)
        return;
    if (unit && value <= 0)
        return;
    if (unit && value) {
        var cssPxPerIn = 96;
        var cmPerIn = 2.54;
        if (unit == 'dppx')
            dppx = value;
        else if (unit === 'dpi')
            dppx = value / cssPxPerIn;
        else if (unit === 'dpcm')
            dppx = value / (cssPxPerIn / cmPerIn);
        else
            return;
    }
    if (fromImage && imgResolutionDppx)
        dppx = imgResolutionDppx;
    if (snap)
        dppx = Math.floor(dppx + 0.01);
    if (dppx <= 0)
        dppx = 1;
    return dppx;
}

function permute3(rule) {
    var s = rule.trim().split(' ');
    if (s.length == 1)
        return s;
    if (s.length == 2)
        return [s.join(' '), [s[1], s[0]].join(' ')];
    return [[s[0], s[1], s[2]].join(' '), [s[0], s[2], s[1]].join(' '),
            [s[1], s[0], s[2]].join(' '), [s[1], s[2], s[0]].join(' '),
            [s[2], s[0], s[1]].join(' '), [s[2], s[1], s[0]].join(' ')];
}

function generateTests(resolutions) {
    var tests = resolutions.slice();
    resolutions.forEach(function(resolution) {
        tests.push.apply(tests, permute3(resolution + ' from-image'));
    });
    resolutions.forEach(function(resolution) {
        tests.push.apply(tests, permute3(resolution + ' snap'));
    });
    resolutions.forEach(function(resolution) {
        tests.push.apply(tests, permute3(resolution + ' from-image snap'));
    });
    return tests;
}

var imgUrl = '../../images/resources/green.jpg';
var imgWidthPx = 16;
var imgHeightPx = 16;
var imgResolutionDppx = 0; /* Embedded image resolution data not plumbed yet. */
var dimensions = imgWidthPx + 'x' + imgHeightPx;

description('Apply image-resolution property to a fixed image (' + dimensions + ').');

var img = document.createElement('img');
img.src = imgUrl;

var resolutions = ['0dppx', '1dppx', '2dppx', '3dppx', '4dppx',
                   '0dpi', '96dpi', '192dpi', '288dpi', '384dpi',
                   '150dpi', '300dpi', '450dpi', '600dpi',
                   '0dpcm', '37.7dpcm', '75.5dpcm', '113.3dpcm', '151.1dpcm', ''];

img.onload = function() {
    generateTests(resolutions).forEach(function(test) {
        var dppx = computeResolution(test, imgResolutionDppx);
        img.style.imageResolution = '';
        img.style.imageResolution = test;
        debug('<span class="pass">TEST</span> "' + test + '"');
        if (!dppx) {
            shouldBe('img.style.cssText', '""');
            return;
        }
        shouldBe('img.style.cssText', '"image-resolution: ' + test + ';"');
        var expectedWidth = Math.floor(imgWidthPx / dppx);
        var expectedHeight = Math.floor(imgHeightPx / dppx);
        shouldBe('img.offsetWidth', stringify(expectedWidth));
        shouldBe('img.offsetHeight', stringify(expectedHeight));
    });
    document.body.removeChild(img);
    finishJSTest();
};

document.body.appendChild(img);
</script>
</body>
</html>