/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

const { utils: Cu, interfaces: Ci, classes: Cc, results: Cr } = Components;

Cu.import("resource://gre/modules/Services.jsm");
Cu.import('resource://gre/modules/Preferences.jsm');
Cu.import("resource://gre/modules/XPCOMUtils.jsm");

const PAGE_WIDTH=72;
const PAGE_HEIGHT=136;
const DRIVER_PREF="sanity-test.driver-version";
const DEVICE_PREF="sanity-test.device-id";
const VERSION_PREF="sanity-test.version";
const DISABLE_VIDEO_PREF="media.hardware-video-decoding.failed";
const RUNNING_PREF="sanity-test.running";

// GRAPHICS_SANITY_TEST histogram enumeration values
const TEST_PASSED=0;
const TEST_FAILED_RENDER=1;
const TEST_FAILED_VIDEO=2;
const TEST_CRASHED=3;

function testPixel(ctx, x, y, r, g, b, a, fuzz) {
  var data = ctx.getImageData(x, y, 1, 1);

  if (Math.abs(data.data[0] - r) <= fuzz &&
      Math.abs(data.data[1] - g) <= fuzz &&
      Math.abs(data.data[2] - b) <= fuzz &&
      Math.abs(data.data[3] - a) <= fuzz) {
    return true;
  }
  return false;
}

function reportResult(val) {
  try {
    let histogram = Services.telemetry.getHistogramById("GRAPHICS_SANITY_TEST");
    histogram.add(val);
  } catch (e) {}

  Preferences.set(RUNNING_PREF, false);
  Services.prefs.savePrefFile(null);
}

function takeWindowSnapshot(win) {
  // Take a snapshot of the window contents, and then close the window
  var canvas = win.createElementNS("http://www.w3.org/1999/xhtml", "canvas");
  canvas.setAttribute("width", PAGE_WIDTH);
  canvas.setAttribute("height", PAGE_HEIGHT);

  // TODO: drawWindow reads back from the gpu's backbuffer, which won't catch issues with presenting
  // the front buffer via the window manager. Ideally we'd use an OS level API for reading back
  // from the desktop itself to get a more accurate test.
  var ctx = canvas.getContext("2d");
  var flags = ctx.DRAWWINDOW_DRAW_CARET | ctx.DRAWWINDOW_DRAW_VIEW | ctx.DRAWWINDOW_USE_WIDGET_LAYERS;
  ctx.drawWindow(win.ownerGlobal, 0, 0, PAGE_WIDTH, PAGE_HEIGHT, "rgb(255,255,255)", flags);

  win.ownerGlobal.close();
  return ctx;
}

// Verify that all the 4 coloured squares of the video
// render as expected (with a tolerance of 64 to allow for
// yuv->rgb differences between platforms).
//
// The video is 64x64, and is split into quadrants of
// different colours. The top left of the video is 8,72
// and we test a pixel 10,10 into each quadrant to avoid
// blending differences at the edges.
//
// We allow massive amounts of fuzz for the colours since
// it can depend hugely on the yuv -> rgb conversion, and
// we don't want to fail unnecessarily.
function verifyVideoRendering(ctx) {
  return testPixel(ctx, 18, 82, 255, 255, 255, 255, 64) &&
    testPixel(ctx, 50, 82, 0, 255, 0, 255, 64) &&
    testPixel(ctx, 18, 114, 0, 0, 255, 255, 64) &&
    testPixel(ctx, 50, 114, 255, 0, 0, 255, 64);
}

function testGfxFeatures(event) {
  var win = event.target;
  var canvas = takeWindowSnapshot(win);

  if (!verifyVideoRendering(canvas)) {
    reportResult(TEST_FAILED_VIDEO);
    Preferences.set(DISABLE_VIDEO_PREF, true);
  } else {
    reportResult(TEST_PASSED);
  }
}

function SanityTest() {}
SanityTest.prototype = {
  classID: Components.ID("{f3a8ca4d-4c83-456b-aee2-6a2cbf11e9bd}"),
  QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
                                         Ci.nsISupportsWeakReference]),

  shouldRunTest: function() {
    // Only test gfx features if firefox has updated, or if the user has a new
    // gpu or drivers.
    var appInfo = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULAppInfo);
    var xulVersion = appInfo.version;
    var gfxinfo = Cc["@mozilla.org/gfx/info;1"].getService(Ci.nsIGfxInfo);

    if (Preferences.get(RUNNING_PREF, false)) {
      Preferences.set(DISABLE_VIDEO_PREF, true);
      reportResult(TEST_CRASHED);
      return false;
    }

    // TODO: Handle dual GPU setups
    if (Preferences.get(DRIVER_PREF, "") == gfxinfo.adapterDriverVersion &&
        Preferences.get(DEVICE_PREF, "") == gfxinfo.adapterDeviceID &&
        Preferences.get(VERSION_PREF, "") == xulVersion) {
      return false;
    }

    // Enable hardware decoding so we can test again
    // and record the driver version to detect if the driver changes.
    Preferences.set(DISABLE_VIDEO_PREF, false);
    Preferences.set(DRIVER_PREF, gfxinfo.adapterDriverVersion);
    Preferences.set(DEVICE_PREF, gfxinfo.adapterDeviceID);
    Preferences.set(VERSION_PREF, xulVersion);

    // Update the prefs so that this test doesn't run again until the next update.
    Preferences.set(RUNNING_PREF, true);
    Services.prefs.savePrefFile(null);
    return true;
  },

  observe: function(subject, topic, data) {
    if (topic != "profile-after-change") return;
    if (!this.shouldRunTest()) return;

    // Open a tiny window to render our test page, and notify us when it's loaded
    var sanityTest = Services.ww.openWindow(null,
        "chrome://gfxsanity/content/sanitytest.html",
        "Test Page",
        "width=" + PAGE_WIDTH + ",height=" + PAGE_HEIGHT + ",chrome,titlebar=0,scrollbars=0",
        null);
    sanityTest.onload = testGfxFeatures;
  },
};

this.NSGetFactory = XPCOMUtils.generateNSGetFactory([SanityTest]);