const CLEARKEY_KEYSYSTEM = "org.w3.clearkey";

const gCencMediaKeySystemConfig = [{
  initDataTypes: ['cenc'],
  videoCapabilities: [{ contentType: 'video/mp4' }],
  audioCapabilities: [{ contentType: 'audio/mp4' }],
}];

function IsMacOSSnowLeopardOrEarlier() {
  var re = /Mac OS X (\d+)\.(\d+)/;
  var ver = navigator.userAgent.match(re);
  if (!ver || ver.length != 3) {
    return false;
  }
  var major = ver[1] | 0;
  var minor = ver[2] | 0;
  return major == 10 && minor <= 6;
}

function bail(message)
{
  return function(err) {
    if (err) {
      message +=  "; " + String(err)
    }
    ok(false, message);
    if (err) {
      info(String(err));
    }
    SimpleTest.finish();
  }
}

function ArrayBufferToString(arr)
{
  var str = '';
  var view = new Uint8Array(arr);
  for (var i = 0; i < view.length; i++) {
    str += String.fromCharCode(view[i]);
  }
  return str;
}

function StringToArrayBuffer(str)
{
  var arr = new ArrayBuffer(str.length);
  var view = new Uint8Array(arr);
  for (var i = 0; i < str.length; i++) {
    view[i] = str.charCodeAt(i);
  }
  return arr;
}

function StringToHex(str){
  var res = "";
  for (var i = 0; i < str.length; ++i) {
      res += ("0" + str.charCodeAt(i).toString(16)).slice(-2);
  }
  return res;
}

function Base64ToHex(str)
{
  var bin = window.atob(str.replace(/-/g, "+").replace(/_/g, "/"));
  var res = "";
  for (var i = 0; i < bin.length; i++) {
    res += ("0" + bin.charCodeAt(i).toString(16)).substr(-2);
  }
  return res;
}

function HexToBase64(hex)
{
  var bin = "";
  for (var i = 0; i < hex.length; i += 2) {
    bin += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
  }
  return window.btoa(bin).replace(/=/g, "").replace(/\+/g, "-").replace(/\//g, "_");
}

function TimeRangesToString(trs)
{
  var l = trs.length;
  if (l === 0) { return "-"; }
  var s = "";
  var i = 0;
  for (;;) {
    s += trs.start(i) + "-" + trs.end(i);
    if (++i === l) { return s; }
    s += ",";
  }
}

function SourceBufferToString(sb)
{
  return ("SourceBuffer{"
    + "AppendMode=" + (sb.AppendMode || "-")
    + ", updating=" + (sb.updating ? "true" : "false")
    + ", buffered=" + TimeRangesToString(sb.buffered)
    + ", audioTracks=" + (sb.audioTracks ? sb.audioTracks.length : "-")
    + ", videoTracks=" + (sb.videoTracks ? sb.videoTracks.length : "-")
    + "}");
}

function SourceBufferListToString(sbl)
{
  return "SourceBufferList[" + sbl.map(SourceBufferToString).join(", ") + "]";
}

function GenerateClearKeyLicense(licenseRequest, keyStore)
{
  var msgStr = ArrayBufferToString(licenseRequest);
  var msg = JSON.parse(msgStr);

  var keys = [];
  for (var i = 0; i < msg.kids.length; i++) {
    var id64 = msg.kids[i];
    var idHex = Base64ToHex(msg.kids[i]).toLowerCase();
    var key = keyStore[idHex];

    if (key) {
      keys.push({
        "kty": "oct",
        "kid": id64,
        "k": HexToBase64(key)
      });
    }
  }

  return new TextEncoder().encode(JSON.stringify({
    "keys" : keys,
    "type" : msg.type || "temporary"
  }));
}

function UpdateSessionFunc(test, token, sessionType, resolve, reject) {
  return function(ev) {
    var license = GenerateClearKeyLicense(ev.message, test.keys);
    Log(token, "sending update message to CDM: " + (new TextDecoder().decode(license)));
    ev.target.update(license).then(function() {
      Log(token, "MediaKeySession update ok!");
      resolve(ev.target);
    }).catch(function(reason) {
      reject(`${token} MediaKeySession update failed: ${reason}`);
    });
  }
}

function MaybeCrossOriginURI(test, uri)
{
  if (test.crossOrigin) {
    return "http://test2.mochi.test:8888/tests/dom/media/test/allowed.sjs?" + uri;
  } else {
    return uri;
  }
}

function AppendTrack(test, ms, track, token)
{
  return new Promise(function(resolve, reject) {
    var sb;
    var curFragment = 0;
    var resolved = false;
    var fragments = track.fragments;
    var fragmentFile;

    function addNextFragment() {
      if (curFragment >= fragments.length) {
        Log(token, track.name + ": end of track");
        resolve();
        resolved = true;
        return;
      }

      fragmentFile = MaybeCrossOriginURI(test, fragments[curFragment++]);

      var req = new XMLHttpRequest();
      req.open("GET", fragmentFile);
      req.responseType = "arraybuffer";

      req.addEventListener("load", function() {
        Log(token, track.name + ": fetch of " + fragmentFile + " complete, appending");
        sb.appendBuffer(new Uint8Array(req.response));
      });

      req.addEventListener("error", function() {
        reject(`${token} - ${track.name}: error fetching ${fragmentFile}`);
      });
      req.addEventListener("abort", function() {
        reject(`${token} - ${track.name}: aborted fetching ${fragmentFile}`);
      });

      Log(token, track.name + ": addNextFragment() fetching next fragment " + fragmentFile);
      req.send(null);
    }

    Log(token, track.name + ": addSourceBuffer(" + track.type + ")");
    sb = ms.addSourceBuffer(track.type);
    sb.addEventListener("updateend", function() {
      if (ms.readyState == "ended") {
        /* We can get another updateevent as a result of calling ms.endOfStream() if
           the highest end time of our source buffers is different from that of the
           media source duration. Due to bug 1065207 this can happen because of
           inaccuracies in the frame duration calculations. Check if we are already
           "ended" and ignore the update event */
        Log(token, track.name + ": updateend when readyState already 'ended'");
        if (!resolved) {
          // Needed if decoder knows this was the last fragment and ended by itself.
          Log(token, track.name + ": but promise not resolved yet -> end of track");
          resolve();
          resolved = true;
        }
        return;
      }
      Log(token, track.name + ": updateend for " + fragmentFile + ", " + SourceBufferToString(sb));
      addNextFragment();
    });

    addNextFragment();
  });
}

//Returns a promise that is resolved when the media element is ready to have
//its play() function called; when it's loaded MSE fragments.
function LoadTest(test, elem, token)
{
  if (!test.tracks) {
    ok(false, token + " test does not have a tracks list");
    return Promise.reject();
  }

  var ms = new MediaSource();
  elem.src = URL.createObjectURL(ms);
  elem.crossOrigin = test.crossOrigin || false;

  return new Promise(function (resolve, reject) {
    ms.addEventListener("sourceopen", function () {
      Log(token, "sourceopen");
      Promise.all(test.tracks.map(function(track) {
        return AppendTrack(test, ms, track, token);
      })).then(function() {
        Log(token, "Tracks loaded, calling MediaSource.endOfStream()");
        ms.endOfStream();
        resolve();
      }).catch(reject);
    }, {once: true});
  });
}

function EMEPromise() {
  var self = this;
  self.promise = new Promise(function(resolve, reject) {
    self.resolve = resolve;
    self.reject = reject;
  });
}

/*
 * Create a new MediaKeys object.
 * Return a promise which will be resolved with a new MediaKeys object,
 * or will be rejected with a string that describes the failure.
 */
function CreateMediaKeys(v, test, token) {
  let p = new EMEPromise;

  function streamType(type) {
    var x = test.tracks.find(o => o.name == type);
    return x ? x.type : undefined;
  }

  function onencrypted(ev) {
    var options = { initDataTypes: [ev.initDataType] };
    if (streamType("video")) {
      options.videoCapabilities = [{contentType: streamType("video")}];
    }
    if (streamType("audio")) {
      options.audioCapabilities = [{contentType: streamType("audio")}];
    }
    navigator.requestMediaKeySystemAccess(CLEARKEY_KEYSYSTEM, [options])
    .then(keySystemAccess => {
      keySystemAccess.createMediaKeys().then(
        p.resolve,
        () => p.reject(`${token} Failed to create MediaKeys object.`)
      );
    }, () => p.reject(`${token} Failed to request key system access.`));
  }

  v.addEventListener("encrypted", onencrypted, {once: true});
  return p.promise;
}

/*
 * Create a new MediaKeys object and provide it to the media element.
 * Return a promise which will be resolved if succeeded, or will be rejected
 * with a string that describes the failure.
 */
function CreateAndSetMediaKeys(v, test, token) {
  let p = new EMEPromise;

  CreateMediaKeys(v, test, token).then(mediaKeys => {
    v.setMediaKeys(mediaKeys).then(
      p.resolve,
      () => p.reject(`${token} Failed to set MediaKeys on <video> element.`)
    );
  }, p.reject)

  return p.promise;
}

/*
 * Collect the init data from 'encrypted' events.
 * Return a promise which will be resolved with the init data when collection
 * is completed (specified by test.sessionCount).
 */
function LoadInitData(v, test, token) {
  let p = new EMEPromise;
  let initDataQueue = [];

  // Call SimpleTest._originalSetTimeout() to bypass the flaky timeout checker.
  let timer = SimpleTest._originalSetTimeout.call(window, () => {
    p.reject(`${token} Timed out in waiting for the init data.`);
  }, 60000);

  function onencrypted(ev) {
    initDataQueue.push(ev);
    Log(token, `got encrypted(${ev.initDataType}, ` +
        `${StringToHex(ArrayBufferToString(ev.initData))}) event.`);
    if (test.sessionCount == initDataQueue.length) {
      p.resolve(initDataQueue);
      clearTimeout(timer);
    }
  }

  v.addEventListener("encrypted", onencrypted);
  return p.promise;
}

/*
 * Generate a license request and update the session.
 * Return a promsise which will be resolved with the updated session
 * or rejected with a string that describes the failure.
 */
function MakeRequest(test, token, ev, session, sessionType) {
  sessionType = sessionType || "temporary";
  let p = new EMEPromise;
  let str = `session[${session.sessionId}].generateRequest(` +
    `${ev.initDataType}, ${StringToHex(ArrayBufferToString(ev.initData))})`;

  session.addEventListener("message",
    UpdateSessionFunc(test, token, sessionType, p.resolve, p.reject));

  Log(token, str);
  session.generateRequest(ev.initDataType, ev.initData)
  .catch(reason => {
    // Reject the promise if generateRequest() failed.
    // Otherwise it will be resolved in UpdateSessionFunc().
    p.reject(`${token}: ${str} failed; ${reason}`);
  });

  return p.promise;
}

/*
 * Process the init data by calling MakeRequest().
 * Return a promise which will be resolved with the updated sessions
 * when all init data are processed or rejected if any failure.
 */
function ProcessInitData(v, test, token, initData, sessionType) {
  return Promise.all(
    initData.map(ev => {
      let session = v.mediaKeys.createSession(sessionType);
      return MakeRequest(test, token, ev, session, sessionType);
    })
  );
}

/*
 * Clean up the |v| element.
 */
function CleanUpMedia(v) {
  v.setMediaKeys(null);
  v.remove();
  v.removeAttribute("src");
  v.load();
}

/*
 * Close all sessions and clean up the |v| element.
 */
function CloseSessions(v, sessions) {
  return Promise.all(sessions.map(s => s.close()))
  .then(CleanUpMedia(v));
}

/*
 * Set up media keys and source buffers for the media element.
 * Return a promise resolved when all key sessions are updated or rejected
 * if any failure.
 */
function SetupEME(v, test, token) {
  let p = new EMEPromise;

  v.onerror = function() {
    p.reject(`${token} got an error event.`);
  }

  Promise.all([
    LoadInitData(v, test, token),
    CreateAndSetMediaKeys(v, test, token),
    LoadTest(test, v, token)])
  .then(values => {
    let initData = values[0];
    return ProcessInitData(v, test, token, initData);
  })
  .then(p.resolve, p.reject);

  return p.promise;
}

function SetupEMEPref(callback) {
  var prefs = [
    [ "media.mediasource.enabled", true ],
    [ "media.mediasource.webm.enabled", true ],
    [ "media.eme.vp9-in-mp4.enabled", true ],
  ];

  if (SpecialPowers.Services.appinfo.name == "B2G" ||
      !manifestVideo().canPlayType("video/mp4")) {
    // XXX remove once we have mp4 PlatformDecoderModules on all platforms.
    prefs.push([ "media.use-blank-decoder", true ]);
  }

  SpecialPowers.pushPrefEnv({ "set" : prefs }, callback);
}

function fetchWithXHR(uri, onLoadFunction) {
  var p = new Promise(function(resolve, reject) {
    var xhr = new XMLHttpRequest();
    xhr.open("GET", uri, true);
    xhr.responseType = "arraybuffer";
    xhr.addEventListener("load", function () {
      is(xhr.status, 200, "fetchWithXHR load uri='" + uri + "' status=" + xhr.status);
      resolve(xhr.response);
    });
    xhr.send();
  });

  if (onLoadFunction) {
    p.then(onLoadFunction);
  }

  return p;
};

function once(target, name, cb) {
  var p = new Promise(function(resolve, reject) {
    target.addEventListener(name, function(arg) {
      resolve(arg);
    }, {once: true});
  });
  if (cb) {
    p.then(cb);
  }
  return p;
}
