/*!
 * Webogram v0.4.9 - messaging web application for MTProto
 * https://github.com/zhukov/webogram
 * Copyright (C) 2014 Igor Zhukov <igor.beatle@gmail.com>
 * https://github.com/zhukov/webogram/blob/master/LICENSE
 */

angular.module('izhukov.utils', [])

.provider('Storage', function () {

  this.setPrefix = function (newPrefix) {
    ConfigStorage.prefix(newPrefix);
  };

  this.$get = ['$q', function ($q) {
    var methods = {};
    angular.forEach(['get', 'set', 'remove'], function (methodName) {
      methods[methodName] = function () {
        var deferred = $q.defer(),
            args = Array.prototype.slice.call(arguments);

        args.push(function (result) {
          deferred.resolve(result);
        });
        ConfigStorage[methodName].apply(ConfigStorage, args);

        return deferred.promise;
      };
    });
    return methods;
  }];

})

.service('qSync', function () {

  return {
    when: function (result) {
      return {then: function (cb) {
        return cb(result);
      }};
    },
    reject: function (result) {
      return {then: function (cb, badcb) {
        if (badcb) {
          return badcb(result);
        }
      }};
    }
  }

})

.service('FileManager', function ($window, $q, $timeout, qSync) {

  $window.URL = $window.URL || $window.webkitURL;
  $window.BlobBuilder = $window.BlobBuilder || $window.WebKitBlobBuilder || $window.MozBlobBuilder;
  var buggyUnknownBlob = navigator.userAgent.indexOf('Safari') != -1 &&
                         navigator.userAgent.indexOf('Chrome') == -1;

  var blobSupported = true;

  try {
    blobConstruct([], '');
  } catch (e) {
    blobSupported = false;
  }

  function isBlobAvailable () {
    return blobSupported;
  }

  function fileCopyTo (fromFileEntry, toFileEntry) {
    return getFileWriter(toFileEntry).then(function (fileWriter) {
      return fileWriteData(fileWriter, fromFileEntry).then(function () {
        return fileWriter;
      }, function (error) {
        return $q.reject(error);
        fileWriter.truncate(0);
      });
    });
  }

  function fileWriteData(fileWriter, bytes) {
    var deferred = $q.defer();

    fileWriter.onwriteend = function(e) {
      deferred.resolve();
    };
    fileWriter.onerror = function (e) {
      deferred.reject(e);
    };

    if (bytes.file) {
      bytes.file(function (file) {
        fileWriter.write(file);
      }, function (error) {
        deferred.reject(error);
      })
    }
    else if (bytes instanceof Blob) { // is file bytes
      fileWriter.write(bytes);
    }
    else {
      try {
        var blob = blobConstruct([bytesToArrayBuffer(bytes)]);
        fileWriter.write(blob);
      } catch (e) {
        deferred.reject(e);
      }
    }

    return deferred.promise;
  }

  function chooseSaveFile (fileName, ext, mimeType) {
    if (!$window.chrome || !chrome.fileSystem || !chrome.fileSystem.chooseEntry) {
      return qSync.reject();
    };
    var deferred = $q.defer();

    chrome.fileSystem.chooseEntry({
      type: 'saveFile',
      suggestedName: fileName,
      accepts: [{
        mimeTypes: [mimeType],
        extensions: [ext]
      }]
    }, function (writableFileEntry) {
      deferred.resolve(writableFileEntry);
    });

    return deferred.promise;
  }

  function getFileWriter (fileEntry) {
    var deferred = $q.defer();

    fileEntry.createWriter(function (fileWriter) {
      deferred.resolve(fileWriter);
    }, function (error) {
      deferred.reject(error);
    });

    return deferred.promise;
  }

  function getFakeFileWriter (mimeType, saveFileCallback) {
    var blobParts = [],
        fakeFileWriter = {
          write: function (blob) {
            if (!blobSupported) {
              if (fakeFileWriter.onerror) {
                fakeFileWriter.onerror(new Error('Blob not supported by browser'));
              }
              return false;
            }
            blobParts.push(blob);
            setZeroTimeout(function () {
              if (fakeFileWriter.onwriteend) {
                fakeFileWriter.onwriteend();
              }
            });
          },
          truncate: function () {
            blobParts = [];
          },
          finalize: function () {
            var blob = blobConstruct(blobParts, mimeType);
            if (saveFileCallback) {
              saveFileCallback(blob);
            }
            return blob;
          }
        };

    return fakeFileWriter;
  };

  function getUrl (fileData, mimeType) {
    // console.log(dT(), 'get url', fileData, mimeType, fileData.toURL !== undefined, fileData instanceof Blob);
    if (fileData.toURL !== undefined) {
      return fileData.toURL(mimeType);
    }
    if (fileData instanceof Blob) {
      return URL.createObjectURL(fileData);
    }
    return 'data:' + mimeType + ';base64,' + bytesToBase64(fileData);
  }

  function getByteArray(fileData) {
    if (fileData instanceof Blob) {
      var deferred = $q.defer();
      try {
        var reader = new FileReader();
        reader.onloadend = function (e) {
          deferred.resolve(new Uint8Array(e.target.result));
        };
        reader.onerror = function (e) {
          deferred.reject(e);
        };
        reader.readAsArrayBuffer(fileData);

        return deferred.promise;
      } catch (e) {
        return $q.reject(e);
      }
    }
    else if (fileData.file) {
      var deferred = $q.defer();
      fileData.file(function (blob) {
        getByteArray(blob).then(function (result) {
          deferred.resolve(result);
        }, function (error) {
          deferred.reject(error);
        })
      }, function (error) {
        deferred.reject(error);
      });
      return deferred.promise;
    }
    return $q.when(fileData);
  }

  function getDataUrl(blob) {
    var deferred;
    try {
      var reader = new FileReader();
      reader.onloadend = function() {
        deferred.resolve(reader.result);
      }
      reader.readAsDataURL(blob);
    } catch (e) {
      return $q.reject(e);
    }

    deferred = $q.defer();

    return deferred.promise;
  }

  function getFileCorrectUrl(blob, mimeType) {
    if (buggyUnknownBlob && blob instanceof Blob) {
      var mimeType = blob.type || blob.mimeType || mimeType || '';
      if (!mimeType.match(/image\/(jpeg|gif|png|bmp)|video\/quicktime/)) {
        return getDataUrl(blob);
      }
    }
    return qSync.when(getUrl(blob, mimeType));
  }

  function downloadFile (blob, mimeType, fileName) {
    if (window.navigator && navigator.msSaveBlob !== undefined) {
      window.navigator.msSaveBlob(blob, fileName);
      return false;
    }

    if (window.navigator && navigator.getDeviceStorage) {
      var storageName = 'sdcard';
      var subdir = 'telegram/';
      switch (mimeType.split('/')[0]) {
        case 'video': storageName = 'videos'; break;
        case 'audio': storageName = 'music'; break;
        case 'image': storageName = 'pictures'; break;
      }
      var deviceStorage = navigator.getDeviceStorage(storageName);

      var request = deviceStorage.addNamed(blob, subdir + fileName);

      request.onsuccess = function () {
        console.log('Device storage save result', this.result);
      };
      request.onerror = function () {
      };
      return;
    }

    var popup = false;
    if (window.safari) {
      popup = window.open();
    }

    getFileCorrectUrl(blob, mimeType).then(function (url) {
      if (popup) {
        try {
          popup.location.href = url;
          return;
        } catch (e) {}
      }
      var anchor = document.createElementNS('http://www.w3.org/1999/xhtml', 'a');
      anchor.href = url;
      anchor.target  = '_blank';
      anchor.download = fileName;
      if (anchor.dataset) {
        anchor.dataset.downloadurl = ["video/quicktime", fileName, url].join(':');
      }
      $(anchor).css({position: 'absolute', top: 1, left: 1}).appendTo('body');

      try {
        var clickEvent = document.createEvent('MouseEvents');
        clickEvent.initMouseEvent(
          'click', true, false, window, 0, 0, 0, 0, 0
          , false, false, false, false, 0, null
        );
        anchor.dispatchEvent(clickEvent);
      } catch (e) {
        console.error('Download click error', e);
        try {
          anchor[0].click();
        } catch (e) {
          window.open(url, '_blank');
        }
      }
      $timeout(function () {
        $(anchor).remove();
      }, 100);
    });
  }

  return {
    isAvailable: isBlobAvailable,
    copy: fileCopyTo,
    write: fileWriteData,
    getFileWriter: getFileWriter,
    getFakeFileWriter: getFakeFileWriter,
    chooseSave: chooseSaveFile,
    getUrl: getUrl,
    getDataUrl: getDataUrl,
    getByteArray: getByteArray,
    getFileCorrectUrl: getFileCorrectUrl,
    download: downloadFile
  };
})

.service('IdbFileStorage', function ($q, $window, FileManager) {

  $window.indexedDB = $window.indexedDB || $window.webkitIndexedDB || $window.mozIndexedDB || $window.OIndexedDB || $window.msIndexedDB;
  $window.IDBTransaction = $window.IDBTransaction || $window.webkitIDBTransaction || $window.OIDBTransaction || $window.msIDBTransaction;

  var dbName = 'cachedFiles';
  var dbStoreName = 'files';
  var dbVersion = 2;
  var openDbPromise;
  var storageIsAvailable = $window.indexedDB !== undefined &&
                           $window.IDBTransaction !== undefined;

  // IndexedDB is REALLY slow without blob support in Safari 8, no point in it
  if (storageIsAvailable &&
      navigator.userAgent.indexOf('Safari') != -1 &&
      navigator.userAgent.indexOf('Chrome') == -1 &&
      navigator.userAgent.match(/Version\/[678]/)
  ) {
    storageIsAvailable = false;
  }

  var storeBlobsAvailable = storageIsAvailable || false;

  function isAvailable () {
    return storageIsAvailable;
  }

  function openDatabase() {
    if (openDbPromise) {
      return openDbPromise;
    }

    try {
      var request = indexedDB.open(dbName, dbVersion),
          deferred = $q.defer(),
          createObjectStore = function (db) {
            db.createObjectStore(dbStoreName);
          };
      if (!request) {
        throw new Exception();
      }
    } catch (error) {
      storageIsAvailable = false;
      return $q.reject(error);
    }

    request.onsuccess = function (event) {
      db = request.result;

      db.onerror = function (error) {
        storageIsAvailable = false;
        console.error('Error creating/accessing IndexedDB database', error);
        deferred.reject(error);
      };

      deferred.resolve(db);
    };

    request.onerror = function (event) {
      storageIsAvailable = false;
      console.error('Error creating/accessing IndexedDB database', event);
      deferred.reject(event);
    }

    request.onupgradeneeded = function (event) {
      console.warn('performing idb upgrade from', event.oldVersion, 'to', event.newVersion);
      var db = event.target.result;
      if (event.oldVersion == 1) {
        db.deleteObjectStore(dbStoreName);
      }
      createObjectStore(db);
    };

    return openDbPromise = deferred.promise;
  };

  function saveFile (fileName, blob) {
    return openDatabase().then(function (db) {
      if (!storeBlobsAvailable) {
        return saveFileBase64(db, fileName, blob);
      }

      if (!(blob instanceof Blob)) {
        blob = blobConstruct([blob]);
      }

      try {
        var objectStore = db.transaction([dbStoreName], IDBTransaction.READ_WRITE || 'readwrite').objectStore(dbStoreName),
            request = objectStore.put(blob, fileName);
      } catch (error) {
        if (storeBlobsAvailable) {
          storeBlobsAvailable = false;
          return saveFileBase64(db, fileName, blob);
        }
        storageIsAvailable = false;
        return $q.reject(error);
      }

      var deferred = $q.defer();

      request.onsuccess = function (event) {
        deferred.resolve(blob);
      };

      request.onerror = function (error) {
        deferred.reject(error);
      };

      return deferred.promise;
    });
  };

  function saveFileBase64(db, fileName, blob) {
    if (getBlobSize(blob) > 10 * 1024 * 1024) {
      return $q.reject();
    }
    try {
      var reader = new FileReader();
      reader.readAsDataURL(blob);
    } catch (e) {
      storageIsAvailable = false;
      return $q.reject();
    }

    var deferred = $q.defer();

    reader.onloadend = function() {
      try {
        var objectStore = db.transaction([dbStoreName], IDBTransaction.READ_WRITE || 'readwrite').objectStore(dbStoreName),
            request = objectStore.put(reader.result, fileName);
      } catch (error) {
        storageIsAvailable = false;
        deferred.reject(error);
        return;
      };
      request.onsuccess = function (event) {
        deferred.resolve(blob);
      };

      request.onerror = function (error) {
        deferred.reject(error);
      };
    }

    return deferred.promise;
  }

  function getBlobSize (blob) {
    return blob.size || blob.byteLength || blob.length;
  }

  function getFile (fileName) {
    return openDatabase().then(function (db) {
      var deferred = $q.defer(),
          objectStore = db.transaction([dbStoreName], IDBTransaction.READ || 'readonly').objectStore(dbStoreName),
          request = objectStore.get(fileName);

      request.onsuccess = function (event) {
        var result = event.target.result;
        if (result === undefined) {
          deferred.reject();
        } else if (typeof result === 'string' &&
                   result.substr(0, 5) === 'data:') {
          deferred.resolve(dataUrlToBlob(result));
        } else {
          deferred.resolve(result);
        }
      };

      request.onerror = function (error) {
        deferred.reject(error);
      };

      return deferred.promise;
    });
  }

  function getFileWriter (fileName, mimeType) {
    var fakeWriter = FileManager.getFakeFileWriter(mimeType, function (blob) {
      saveFile(fileName, blob);
    });
    return $q.when(fakeWriter);
  }

  openDatabase();

  return {
    isAvailable: isAvailable,
    saveFile: saveFile,
    getFile: getFile,
    getFileWriter: getFileWriter
  };
})


.service('TmpfsFileStorage', function ($q, $window, FileManager) {

  $window.requestFileSystem = $window.requestFileSystem || $window.webkitRequestFileSystem;

  var reqFsPromise,
      fileSystem,
      storageIsAvailable = $window.requestFileSystem !== undefined;

  function requestFS () {
    if (reqFsPromise) {
      return reqFsPromise;
    }

    if (!$window.requestFileSystem) {
      return reqFsPromise = $q.reject({type: 'FS_BROWSER_UNSUPPORTED', description: 'requestFileSystem not present'});
    }

    var deferred = $q.defer();

    $window.requestFileSystem($window.TEMPORARY, 500 * 1024 * 1024, function (fs) {
      cachedFs = fs;
      deferred.resolve();
    }, function (e) {
      storageIsAvailable = false;
      deferred.reject(e);
    });

    return reqFsPromise = deferred.promise;
  };

  function isAvailable () {
    return storageIsAvailable;
  }

  function getFile (fileName, size) {
    size = size || 1;
    return requestFS().then(function () {
      // console.log(dT(), 'get file', fileName);
      var deferred = $q.defer();
      cachedFs.root.getFile(fileName, {create: false}, function(fileEntry) {
        fileEntry.file(function(file) {
          // console.log(dT(), 'aa', file);
          if (file.size >= size) {
            deferred.resolve(fileEntry);
          } else {
            deferred.reject(new Error('FILE_NOT_FOUND'));
          }
        }, function (error) {
          console.log(dT(), 'error', error);
          deferred.reject(error);
        });
      }, function () {
        deferred.reject(new Error('FILE_NOT_FOUND'));
      });
      return deferred.promise;
    });
  }

  function saveFile (fileName, blob) {
    return getFileWriter(fileName).then(function (fileWriter) {
      return FileManager.write(fileWriter, blob).then(function () {
        return fileWriter.finalize();
      })
    });
  }

  function getFileWriter (fileName) {
    // console.log(dT(), 'get file writer', fileName);
    return requestFS().then(function () {
      var deferred = $q.defer();
      cachedFs.root.getFile(fileName, {create: true}, function (fileEntry) {
        FileManager.getFileWriter(fileEntry).then(function (fileWriter) {
          fileWriter.finalize = function () {
            return fileEntry;
          }
          deferred.resolve(fileWriter);
        }, function (error) {
          storageIsAvailable = false;
          deferred.reject(error);
        });
      }, function (error) {
        storageIsAvailable = false;
        deferred.reject(error);
      });

      return deferred.promise;
    })
  }

  requestFS();

  return {
    isAvailable: isAvailable,
    saveFile: saveFile,
    getFile: getFile,
    getFileWriter: getFileWriter
  };
})

.service('MemoryFileStorage', function ($q, FileManager) {

  var storage = {};

  function isAvailable () {
    return true;
  }

  function getFile (fileName, size) {
    if (storage[fileName]) {
      return $q.when(storage[fileName]);
    }
    return $q.reject(new Error('FILE_NOT_FOUND'));
  }

  function saveFile (fileName, blob) {
    return $q.when(storage[fileName] = blob);
  }

  function getFileWriter (fileName, mimeType) {
    var fakeWriter = FileManager.getFakeFileWriter(mimeType, function (blob) {
      saveFile(fileName, blob);
    });
    return $q.when(fakeWriter);
  }

  return {
    isAvailable: isAvailable,
    saveFile: saveFile,
    getFile: getFile,
    getFileWriter: getFileWriter
  };
})

.service('WebpManager', function (qSync, $q) {
  var nativeWebpSupport = false;

  var image = new Image();
  image.onload = function () {
    nativeWebpSupport = this.width === 2 && this.height === 1;
  };
  image.onerror = function () {
    nativeWebpSupport = false;
  };
  image.src = 'data:image/webp;base64,UklGRjIAAABXRUJQVlA4ICYAAACyAgCdASoCAAEALmk0mk0iIiIiIgBoSygABc6zbAAA/v56QAAAAA==';

  var canvas, context;

  function getCanvasFromWebp(data) {
    var start = tsNow();

    var decoder = new WebPDecoder();

    var config = decoder.WebPDecoderConfig;
    var buffer = config.j || config.output;
    var bitstream = config.input;

    if (!decoder.WebPInitDecoderConfig(config)) {
      console.error('[webpjs] Library version mismatch!');
      return false;
    }

    // console.log('[webpjs] status code', decoder.VP8StatusCode);
    var StatusCode = decoder.VP8StatusCode;

    status = decoder.WebPGetFeatures(data, data.length, bitstream);
    if (status != (StatusCode.VP8_STATUS_OK || 0)) {
      console.error('[webpjs] status error', status, StatusCode);
    }

    var mode = decoder.WEBP_CSP_MODE;
    buffer.colorspace = mode.MODE_RGBA;
    buffer.J = 4;

    try {
      status = decoder.WebPDecode(data, data.length, config);
    } catch (e) {
      status = e;
    }

    ok = (status == 0);
    if (!ok) {
      console.error('[webpjs] decoding failed', status, StatusCode);
      return false;
    }

    // console.log('[webpjs] decoded: ', buffer.width, buffer.height, bitstream.has_alpha, 'Now saving...');
    var bitmap = buffer.c.RGBA.ma;

    // console.log('[webpjs] done in ', tsNow() - start);

    if (!bitmap) {
      return false;
    }
    var biHeight = buffer.height;
    var biWidth = buffer.width;

    if (!canvas || !context) {
      canvas = document.createElement('canvas');
      context = canvas.getContext('2d');
    } else {
      context.clearRect(0, 0, canvas.width, canvas.height);
    }
    canvas.height = biHeight;
    canvas.width = biWidth;

    var output = context.createImageData(canvas.width, canvas.height);
    var outputData = output.data;

    for (var h = 0; h < biHeight; h++) {
      for (var w = 0; w < biWidth; w++) {
        outputData[0+w*4+(biWidth*4)*h] = bitmap[1+w*4+(biWidth*4)*h];
        outputData[1+w*4+(biWidth*4)*h] = bitmap[2+w*4+(biWidth*4)*h];
        outputData[2+w*4+(biWidth*4)*h] = bitmap[3+w*4+(biWidth*4)*h];
        outputData[3+w*4+(biWidth*4)*h] = bitmap[0+w*4+(biWidth*4)*h];

      };
    }

    context.putImageData(output, 0, 0);

    return true;
  }

  function getPngBlobFromWebp (data) {
    if (!getCanvasFromWebp(data)) {
      return $q.reject({type: 'WEBP_PROCESS_FAILED'});
    }
    if (canvas.toBlob === undefined) {
      return qSync.when(dataUrlToBlob(canvas.toDataURL('image/png')));
    }

    var deferred = $q.defer();
    canvas.toBlob(function (blob) {
      deferred.resolve(blob);
    }, 'image/png');
    return deferred.promise;
  }

  return {
    isWebpSupported: function () {
      return nativeWebpSupport;
    },
    getPngBlobFromWebp: getPngBlobFromWebp
  }

})


.service('CryptoWorker', function ($timeout, $q) {

  var webWorker = false,
      naClEmbed = false,
      taskID = 0,
      awaiting = {},
      webCrypto = Config.Modes.webcrypto && window.crypto && (window.crypto.subtle || window.crypto.webkitSubtle)/* || window.msCrypto && window.msCrypto.subtle*/,
      useSha1Crypto = webCrypto && webCrypto.digest !== undefined,
      useSha256Crypto = webCrypto && webCrypto.digest !== undefined,
      finalizeTask = function (taskID, result) {
        var deferred = awaiting[taskID];
        if (deferred !== undefined) {
          // console.log(dT(), 'CW done');
          deferred.resolve(result);
          delete awaiting[taskID];
        }
      };

  if (Config.Modes.nacl &&
      navigator.mimeTypes &&
      navigator.mimeTypes['application/x-pnacl'] !== undefined) {
    var listener = $('<div id="nacl_listener"><embed id="mtproto_crypto" width="0" height="0" src="nacl/mtproto_crypto.nmf" type="application/x-pnacl" /></div>').appendTo($('body'))[0];
    listener.addEventListener('load', function (e) {
      naClEmbed = listener.firstChild;
      console.log(dT(), 'NaCl ready');
    }, true);
    listener.addEventListener('message', function (e) {
      finalizeTask(e.data.taskID, e.data.result);
    }, true);
    listener.addEventListener('error', function (e) {
      console.error('NaCl error', e);
    }, true);
  }

  if (window.Worker) {
    var tmpWorker = new Worker('js/lib/crypto_worker.js');
    tmpWorker.onmessage = function (e) {
      if (!webWorker) {
        webWorker = tmpWorker;
      } else {
        finalizeTask(e.data.taskID, e.data.result);
      }
    };
    tmpWorker.onerror = function(error) {
      console.error('CW error', error, error.stack);
      webWorker = false;
    };
  }

  function performTaskWorker (task, params, embed) {
    // console.log(dT(), 'CW start', task);
    var deferred = $q.defer();

    awaiting[taskID] = deferred;

    params.task = task;
    params.taskID = taskID;
    (embed || webWorker).postMessage(params);

    taskID++;

    return deferred.promise;
  }

  return {
    sha1Hash: function (bytes) {
      if (useSha1Crypto) {
        // We don't use buffer since typedArray.subarray(...).buffer gives the whole buffer and not sliced one. webCrypto.digest supports typed array
        var deferred = $q.defer(),
            bytesTyped = Array.isArray(bytes) ? convertToUint8Array(bytes) : bytes;
        // console.log(dT(), 'Native sha1 start');
        webCrypto.digest({name: 'SHA-1'}, bytesTyped).then(function (digest) {
          // console.log(dT(), 'Native sha1 done');
          deferred.resolve(digest);
        }, function  (e) {
          console.error('Crypto digest error', e);
          useSha1Crypto = false;
          deferred.resolve(sha1HashSync(bytes));
        });

        return deferred.promise;
      }
      return $timeout(function () {
        return sha1HashSync(bytes);
      });
    },
    sha256Hash: function (bytes) {
      if (useSha256Crypto) {
        var deferred = $q.defer(),
            bytesTyped = Array.isArray(bytes) ? convertToUint8Array(bytes) : bytes;
        // console.log(dT(), 'Native sha1 start');
        webCrypto.digest({name: 'SHA-256'}, bytesTyped).then(function (digest) {
          // console.log(dT(), 'Native sha1 done');
          deferred.resolve(digest);
        }, function  (e) {
          console.error('Crypto digest error', e);
          useSha256Crypto = false;
          deferred.resolve(sha256HashSync(bytes));
        });

        return deferred.promise;
      }
      return $timeout(function () {
        return sha256HashSync(bytes);
      });
    },
    aesEncrypt: function (bytes, keyBytes, ivBytes) {
      if (naClEmbed) {
        return performTaskWorker('aes-encrypt', {
          bytes: addPadding(convertToArrayBuffer(bytes)),
          keyBytes: convertToArrayBuffer(keyBytes),
          ivBytes: convertToArrayBuffer(ivBytes)
        }, naClEmbed);
      }
      return $timeout(function () {
        return convertToArrayBuffer(aesEncryptSync(bytes, keyBytes, ivBytes));
      });
    },
    aesDecrypt: function (encryptedBytes, keyBytes, ivBytes) {
      if (naClEmbed) {
        return performTaskWorker('aes-decrypt', {
          encryptedBytes: addPadding(convertToArrayBuffer(encryptedBytes)),
          keyBytes: convertToArrayBuffer(keyBytes),
          ivBytes: convertToArrayBuffer(ivBytes)
        }, naClEmbed);
      }
      return $timeout(function () {
        return convertToArrayBuffer(aesDecryptSync(encryptedBytes, keyBytes, ivBytes));
      });
    },
    factorize: function (bytes) {
      bytes = convertToByteArray(bytes);
      if (naClEmbed && bytes.length <= 8) {
        return performTaskWorker('factorize', {bytes: bytes}, naClEmbed);
      }
      if (webWorker) {
        return performTaskWorker('factorize', {bytes: bytes});
      }
      return $timeout(function () {
        return pqPrimeFactorization(bytes);
      });
    },
    modPow: function (x, y, m) {
      if (webWorker) {
        return performTaskWorker('mod-pow', {
          x: x,
          y: y,
          m: m
        });
      }
      return $timeout(function () {
        return bytesModPow(x, y, m);
      });
    },
  };
})

.service('ExternalResourcesManager', function ($q, $http) {
  var urlPromises = {};

  function downloadImage (url) {
    if (urlPromises[url] !== undefined) {
      return urlPromises[url];
    }

    return urlPromises[url] = $http.get(url, {responseType: 'blob', transformRequest: null})
      .then(function (response) {
        window.URL = window.URL || window.webkitURL;
        return window.URL.createObjectURL(response.data);
      });
  }

  return {
    downloadImage: downloadImage
  }
})

.service('IdleManager', function ($rootScope, $window, $timeout) {

  $rootScope.idle = {isIDLE: false};

  var toPromise, started = false;

  var hidden = 'hidden';
  var visibilityChange = 'visibilitychange';
  if (typeof document.hidden !== 'undefined') {
    // default
  } else if (typeof document.mozHidden !== 'undefined') {
    hidden = 'mozHidden';
    visibilityChange = 'mozvisibilitychange';
  } else if (typeof document.msHidden !== 'undefined') {
    hidden = 'msHidden';
    visibilityChange = 'msvisibilitychange';
  } else if (typeof document.webkitHidden !== 'undefined') {
    hidden = 'webkitHidden';
    visibilityChange = 'webkitvisibilitychange';
  }

  return {
    start: start
  };

  function start () {
    if (!started) {
      started = true;
      $($window).on(visibilityChange + ' blur focus keydown mousedown touchstart', onEvent);

      setTimeout(function () {
        onEvent({type: 'blur'});
      }, 0);
    }
  }

  function onEvent (e) {
    // console.log('event', e.type);
    if (e.type == 'mousemove') {
      var e = e.originalEvent || e;
      if (e && e.movementX === 0 && e.movementY === 0) {
        return;
      }
      $($window).off('mousemove', onEvent);
    }

    var isIDLE = e.type == 'blur' || e.type == 'timeout' ? true : false;
    if (hidden && document[hidden]) {
      isIDLE = true;
    }

    $timeout.cancel(toPromise);
    if (!isIDLE) {
      // console.log('update timeout');
      toPromise = $timeout(function () {
        onEvent({type: 'timeout'});
      }, 30000);
    }

    if (e.type == 'focus' && !$rootScope.idle.afterFocus) {
      $rootScope.idle.afterFocus = true;
      setTimeout(function () {
        delete $rootScope.idle.afterFocus;
      }, 10);
    }

    if ($rootScope.idle.isIDLE == isIDLE) {
      return;
    }

    // console.log('IDLE changed', isIDLE);
    $rootScope.$apply(function () {
      $rootScope.idle.isIDLE = isIDLE;
    });

    if (isIDLE && e.type == 'timeout') {
      $($window).on('mousemove', onEvent);
    }
  }
})

.service('AppRuntimeManager', function ($window) {

  return {
    reload: function () {
      try {
        location.reload();
      } catch (e) {};

      if ($window.chrome && chrome.runtime && chrome.runtime.reload) {
        chrome.runtime.reload();
      };
    },
    close: function () {
      try {
        $window.close();
      } catch (e) {}
    },
    focus: function () {
      if (window.navigator.mozApps && document.hidden) {
        // Get app instance and launch it to bring app to foreground
        window.navigator.mozApps.getSelf().onsuccess = function() {
          this.result.launch();
        };
      } else {
        if (window.chrome && chrome.app && chrome.app.window) {
          chrome.app.window.current().focus();
        }
        window.focus();
      }
    }
  }
})

.service('RichTextProcessor', function ($sce, $sanitize) {

  var emojiMap = {},
      emojiData = Config.Emoji,
      emojiIconSize = 18,
      emojiSupported = navigator.userAgent.search(/OS X|iPhone|iPad|iOS|Android/i) != -1,
      emojiCode;

  var emojiRegExp = "\\u0023\\u20E3|\\u00a9|\\u00ae|\\u203c|\\u2049|\\u2139|[\\u2194-\\u2199]|\\u21a9|\\u21aa|\\u231a|\\u231b|\\u23e9|[\\u23ea-\\u23ec]|\\u23f0|\\u24c2|\\u25aa|\\u25ab|\\u25b6|\\u2611|\\u2614|\\u26fd|\\u2705|\\u2709|[\\u2795-\\u2797]|\\u27a1|\\u27b0|\\u27bf|\\u2934|\\u2935|[\\u2b05-\\u2b07]|\\u2b1b|\\u2b1c|\\u2b50|\\u2b55|\\u3030|\\u303d|\\u3297|\\u3299|[\\uE000-\\uF8FF\\u270A-\\u2764\\u2122\\u25C0\\u25FB-\\u25FE\\u2615\\u263a\\u2648-\\u2653\\u2660-\\u2668\\u267B\\u267F\\u2693\\u261d\\u26A0-\\u26FA\\u2708\\u2702\\u2601\\u260E]|[\\u2600\\u26C4\\u26BE\\u23F3\\u2764]|\\uD83D[\\uDC00-\\uDFFF]|\\uD83C[\\uDDE8-\\uDDFA\uDDEC]\\uD83C[\\uDDEA-\\uDDFA\uDDE7]|[0-9]\\u20e3|\\uD83C[\\uDC00-\\uDFFF]";

  for (emojiCode in emojiData) {
    emojiMap[emojiData[emojiCode][0]] = emojiCode;
  }

  var alphaCharsRegExp = "a-z" +
                        "\\u00c0-\\u00d6\\u00d8-\\u00f6\\u00f8-\\u00ff" + // Latin-1
                        "\\u0100-\\u024f" + // Latin Extended A and B
                        "\\u0253\\u0254\\u0256\\u0257\\u0259\\u025b\\u0263\\u0268\\u026f\\u0272\\u0289\\u028b" + // IPA Extensions
                        "\\u02bb" + // Hawaiian
                        "\\u0300-\\u036f" + // Combining diacritics
                        "\\u1e00-\\u1eff" + // Latin Extended Additional (mostly for Vietnamese)
                        "\\u0400-\\u04ff\\u0500-\\u0527" +  // Cyrillic
                        "\\u2de0-\\u2dff\\ua640-\\ua69f" +  // Cyrillic Extended A/B
                        "\\u0591-\\u05bf\\u05c1-\\u05c2\\u05c4-\\u05c5\\u05c7" +
                        "\\u05d0-\\u05ea\\u05f0-\\u05f4" + // Hebrew
                        "\\ufb1d-\\ufb28\\ufb2a-\\ufb36\\ufb38-\\ufb3c\\ufb3e\\ufb40-\\ufb41" +
                        "\\ufb43-\\ufb44\\ufb46-\\ufb4f" + // Hebrew Pres. Forms
                        "\\u0610-\\u061a\\u0620-\\u065f\\u066e-\\u06d3\\u06d5-\\u06dc" +
                        "\\u06de-\\u06e8\\u06ea-\\u06ef\\u06fa-\\u06fc\\u06ff" + // Arabic
                        "\\u0750-\\u077f\\u08a0\\u08a2-\\u08ac\\u08e4-\\u08fe" + // Arabic Supplement and Extended A
                        "\\ufb50-\\ufbb1\\ufbd3-\\ufd3d\\ufd50-\\ufd8f\\ufd92-\\ufdc7\\ufdf0-\\ufdfb" + // Pres. Forms A
                        "\\ufe70-\\ufe74\\ufe76-\\ufefc" + // Pres. Forms B
                        "\\u200c" +                        // Zero-Width Non-Joiner
                        "\\u0e01-\\u0e3a\\u0e40-\\u0e4e" + // Thai
                        "\\u1100-\\u11ff\\u3130-\\u3185\\uA960-\\uA97F\\uAC00-\\uD7AF\\uD7B0-\\uD7FF" + // Hangul (Korean)
                        "\\u3003\\u3005\\u303b" +           // Kanji/Han iteration marks
                        "\\uff21-\\uff3a\\uff41-\\uff5a" +  // full width Alphabet
                        "\\uff66-\\uff9f" +                 // half width Katakana
                        "\\uffa1-\\uffdc";                  // half width Hangul (Korean)

  var alphaNumericRegExp  = "0-9\_" + alphaCharsRegExp;

  var domainAddChars = "\u00b7";

  // Based on Regular Expression for URL validation by Diego Perini
  var urlRegExp =  "((?:https?|ftp)://|mailto:)?" +
    // user:pass authentication
    "(?:\\S{1,64}(?::\\S{0,64})?@)?" +
    "(?:" +
      // sindresorhus/ip-regexp
      "(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])(?:\\.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])){3}" +
    "|" +
      // host name
      "[" + alphaCharsRegExp + "0-9][" + alphaCharsRegExp + domainAddChars + "0-9\-]{0,64}" +
      // domain name
      "(?:\\.[" + alphaCharsRegExp + "0-9][" + alphaCharsRegExp + domainAddChars + "0-9\-]{0,64}){0,10}" +

      // TLD identifier
      "(?:\\.(xn--[0-9a-z]{2,16}|[" + alphaCharsRegExp + "]{2,24}))" +
    ")" +
    // port number
    "(?::\\d{2,5})?" +
    // resource path
    "(?:/(?:\\S{0,255}[^\\s.;,(\\[\\]{}<>\"'])?)?";

  var usernameRegExp = "[a-zA-Z\\d_]{5,32}";
  var botCommandRegExp = "\\/([a-zA-Z\\d_]{1,32})(?:@(" + usernameRegExp + "))?(\\b|$)"

  var fullRegExp = new RegExp('(^| )(@)(' + usernameRegExp + ')|(' + urlRegExp + ')|(\\n)|(' + emojiRegExp + ')|(^|\\s)(#[' + alphaNumericRegExp + ']{2,64})|(^|\\s)' + botCommandRegExp, 'i');

  var emailRegExp = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
  var youtubeRegExp = /^(?:https?:\/\/)?(?:www\.)?youtu(?:|\.be|be\.com|\.b)(?:\/v\/|\/watch\\?v=|e\/|(?:\/\??#)?\/watch(?:.+)v=)(.{11})(?:\&[^\s]*)?/;
  var vimeoRegExp = /^(?:https?:\/\/)?(?:www\.)?vimeo\.com\/(\d+)/;
  var instagramRegExp = /^https?:\/\/(?:instagr\.am\/p\/|instagram\.com\/p\/)([a-zA-Z0-9\-\_]+)/i;
  var vineRegExp = /^https?:\/\/vine\.co\/v\/([a-zA-Z0-9\-\_]+)/i;
  var twitterRegExp = /^https?:\/\/twitter\.com\/.+?\/status\/\d+/i;
  var facebookRegExp = /^https?:\/\/(?:www\.|m\.)?facebook\.com\/(?:.+?\/posts\/\d+|(?:story\.php|permalink\.php)\?story_fbid=(\d+)(?:&substory_index=\d+)?&id=(\d+))/i;
  var gplusRegExp = /^https?:\/\/plus\.google\.com\/\d+\/posts\/[a-zA-Z0-9\-\_]+/i;
  var soundcloudRegExp = /^https?:\/\/(?:soundcloud\.com|snd\.sc)\/([a-zA-Z0-9%\-\_]+)\/([a-zA-Z0-9%\-\_]+)/i;
  var spotifyRegExp = /(https?:\/\/(open\.spotify\.com|play\.spotify\.com|spoti\.fi)\/(.+)|spotify:(.+))/i;

  var markdownRegExp = /(^|\s)(````?)([\s\S]+?)(````?)([\s\.,:?!;]|$)|(^|\s)`([^\n]+?)`([\s\.,:?!;]|$)/;

  var siteHashtags = {
    Telegram: '#/im?q=%23{1}',
    Twitter: 'https://twitter.com/hashtag/{1}',
    Instagram: 'https://instagram.com/explore/tags/{1}/',
    'Google Plus': 'https://plus.google.com/explore/{1}'
  };

  var siteMentions = {
    Telegram: '#/im?p=%40{1}',
    Twitter: 'https://twitter.com/{1}',
    Instagram: 'https://instagram.com/{1}/',
    GitHub: 'https://github.com/{1}'
  };

  return {
    wrapRichText: wrapRichText,
    wrapPlainText: wrapPlainText,
    parseEntities: parseEntities,
    parseMarkdown: parseMarkdown,
    mergeEntities: mergeEntities
  };

  function getEmojiSpritesheetCoords(emojiCode) {
    var i, row, column, totalColumns;
    for (var cat = 0; cat < Config.EmojiCategories.length; cat++) {
      totalColumns = Config.EmojiCategorySpritesheetDimens[cat][1];
      i = Config.EmojiCategories[cat].indexOf(emojiCode);
      if (i > -1) {
        row = Math.floor(i / totalColumns);
        column = (i % totalColumns);
        return { category: cat, row: row, column: column };
      }
    }
    console.error('emoji not found in spritesheet', emojiCode);
    return null;
  }

  function parseEntities (text, options) {
    options = options || {};

    var match,
        raw = text,
        url,
        entities = [],
        emojiCode,
        emojiCoords,
        matchIndex,
        rawOffset = 0;

    // var start = tsNow();

    while ((match = raw.match(fullRegExp))) {
      matchIndex = rawOffset + match.index;

      if (match[3]) { // mentions
        entities.push({
          _: 'messageEntityMention',
          offset: matchIndex + match[1].length,
          length: match[2].length + match[3].length
        });
      }
      else if (match[4]) {
        if (emailRegExp.test(match[4])) { // email
          entities.push({
            _: 'messageEntityEmail',
            offset: matchIndex,
            length: match[4].length
          });
        } else {
          var url = false,
              protocol = match[5],
              tld = match[6],
              excluded = '';

          if (tld) { // URL
            if (!protocol && (tld.substr(0, 4) === 'xn--' || Config.TLD.indexOf(tld.toLowerCase()) !== -1)) {
              protocol = 'http://';
            }

            if (protocol) {
              var balanced = checkBrackets(match[4]);

              if (balanced.length !== match[4].length) {
                excluded = match[4].substring(balanced.length);
                match[4] = balanced;
              }

              url = (match[5] ? '' : protocol) + match[4];
            }

            var tgMeMatch;
            if (tld == 'me' &&
                (tgMeMatch = url.match(/^https?:\/\/telegram\.me\/(.+)/))) {
              var path = tgMeMatch[1].split('/');
              switch (path[0]) {
                case 'joinchat':
                  url = 'tg://join?invite=' + path[1];
                  break;
                case 'addstickers':
                  url = 'tg://addstickers?set=' + path[1];
                  break;
                default:
                  var domainQuery = path[0].split('?');
                  url = 'tg://resolve?domain=' + domainQuery[0] + (domainQuery[1] ? '&' + domainQuery[1] : '');
              }
            }
          } else { // IP address
            url = (match[5] ? '' : 'http://') + match[4];
          }

          if (url) {
            entities.push({
              _: 'messageEntityUrl',
              offset: matchIndex,
              length: match[4].length
            });
          }
        }
      }
      else if (match[7]) { // New line
        entities.push({
          _: 'messageEntityLinebreak',
          offset: matchIndex,
          length: 1
        });
      }
      else if (match[8]) { // Emoji
        if ((emojiCode = emojiMap[match[8]]) &&
            (emojiCoords = getEmojiSpritesheetCoords(emojiCode))) {

          entities.push({
            _: 'messageEntityEmoji',
            offset: matchIndex,
            length: match[0].length,
            coords: emojiCoords,
            title: emojiData[emojiCode][1][0]
          });
        }
      }
      else if (match[10]) { // Hashtag
        entities.push({
          _: 'messageEntityHashtag',
          offset: matchIndex + match[9].length,
          length: match[10].length
        });
      }
      else if (match[12]) { // Bot command
        entities.push({
          _: 'messageEntityBotCommand',
          offset: matchIndex + match[11].length,
          length: 1 + match[12].length + (match[13] ? 1 + match[13].length : 0)
        });
      }
      raw = raw.substr(match.index + match[0].length);
      rawOffset += match.index + match[0].length;
    }

    // if (entities.length) {
    //   console.log('parse entities', text, entities.slice());
    // }

    return entities;
  }

  function parseMarkdown (text, entities) {
    if (text.indexOf('`') == -1) {
      return text;
    }
    var raw = text;
    var match;
    var newText = [];
    var rawOffset = 0;
    var matchIndex;
    while (match = raw.match(markdownRegExp)) {
      matchIndex = rawOffset + match.index;
      newText.push(raw.substr(0, match.index));

      var text = (match[3] || match[7]).replace(/^\s+|\s+$/g, '');
      if (text.match(/^`*$/)) {
        newText.push(match[0]);
      }
      else if (match[3]) { // pre
        newText.push(match[1] + text + match[5]);
        entities.push({
          _: 'messageEntityPre',
          language: '',
          offset: matchIndex + match[1].length,
          length: text.length
        });
        rawOffset -= match[2].length + match[4].length;
      } else { // code
        newText.push(match[6] + text + match[8]);
        entities.push({
          _: 'messageEntityCode',
          offset: matchIndex + match[6].length,
          length: text.length
        });
        rawOffset -= 2;
      }
      raw = raw.substr(match.index + match[0].length);
      rawOffset += match.index + match[0].length;
    }
    newText.push(raw);
    newText = newText.join('');

    if (!newText.replace(/\s+/g, '').length) {
      newText = text;
      entities.splice(0, entities.length);
    }
    return newText;
  }

  function mergeEntities (currentEntities, newEntities, fromApi) {
    var totalEntities = newEntities.slice();

    var i, len = currentEntities.length;
    var j, len2 = newEntities.length;
    var startJ = 0;
    var curEntity, newEntity;
    var start, end, cStart, cEnd, bad;
    for (i = 0; i < len; i++) {
      curEntity = currentEntities[i];
      if (fromApi &&
          curEntity._ != 'messageEntityLinebreak' &&
          curEntity._ != 'messageEntityEmoji') {
        continue;
      }
      // console.log('s', curEntity, newEntities);
      start = curEntity.offset;
      end = start + curEntity.length;
      bad = false;
      for (j = startJ; j < len2; j++) {
        newEntity = newEntities[j];
        cStart = newEntity.offset;
        cEnd = cStart + newEntity.length;
        if (cStart <= start) {
          startJ = j;
        }
        if (start >= cStart && start < cEnd ||
            end > cStart && end <= cEnd) {
          // console.log('bad', curEntity, newEntity);
          if (fromApi &&
              start >= cStart && end <= cEnd) {
            if (newEntity.nested === undefined) {
              newEntity.nested = [];
            }
            curEntity.offset -= cStart;
            newEntity.nested.push(angular.copy(curEntity));
          }
          bad = true;
          break;
        }
        if (cStart >= end) {
          break;
        }
      }
      if (bad) {
        continue;
      }
      totalEntities.push(curEntity);
    }

    totalEntities.sort(function (a, b) {
      return a.offset - b.offset;
    });

    // console.log('merge', currentEntities, newEntities, totalEntities);

    return totalEntities;
  }

  function wrapRichNestedText (text, nested, options) {
    if (nested === undefined) {
      return encodeEntities(text);
    }

    return wrapRichText(text, {entities: nested, nested: true});
  }

  function wrapRichText (text, options) {
    if (!text || !text.length) {
      return '';
    }

    options = options || {};

    var entities = options.entities,
        contextSite = options.contextSite || 'Telegram',
        contextExternal = contextSite != 'Telegram',
        emojiFound = false;

    if (entities === undefined) {
      entities = parseEntities(text, options);
    }

    var i = 0;
    var len = entities.length;
    var entity;
    var entityText;
    var skipEntity;
    var url;
    var html = [];
    var lastOffset = 0;
    for (i = 0; i < len; i++) {
      entity = entities[i];
      if (entity.offset > lastOffset) {
        html.push(
          encodeEntities(text.substr(lastOffset, entity.offset - lastOffset))
        );
      }
      else if (entity.offset < lastOffset) {
        continue;
      }
      skipEntity = false;
      entityText = text.substr(entity.offset, entity.length);
      switch (entity._) {
        case 'messageEntityMention':
          var contextUrl = !options.noLinks && siteMentions[contextSite];
          if (!contextUrl) {
            skipEntity = true;
            break;
          }
          var username = entityText.substr(1);
          var attr = '';
          if (options.highlightUsername &&
              options.highlightUsername.toLowerCase() == username.toLowerCase()) {
            attr = 'class="im_message_mymention"';
          }
          html.push(
            '<a ',
            attr,
            contextExternal ? ' target="_blank" ' : '',
            ' href="',
            contextUrl.replace('{1}', encodeURIComponent(username)),
            '">',
            encodeEntities(entityText),
            '</a>'
          );
          break;

        case 'messageEntityHashtag':
          var contextUrl = !options.noLinks && siteHashtags[contextSite];
          if (!contextUrl) {
            skipEntity = true;
            break;
          }
          var hashtag = entityText.substr(1);
          html.push(
            '<a ',
            contextExternal ? ' target="_blank" ' : '',
            'href="',
            contextUrl.replace('{1}', encodeURIComponent(hashtag))
            ,
            '">',
            encodeEntities(entityText),
            '</a>'
          );
          break;

        case 'messageEntityEmail':
          if (options.noLinks) {
            skipEntity = true;
            break;
          }
          html.push(
            '<a href="',
            encodeEntities('mailto:' + entityText),
            '" target="_blank">',
            encodeEntities(entityText),
            '</a>'
          );
          break;

        case 'messageEntityUrl':
        case 'messageEntityTextUrl':
          if (options.noLinks) {
            skipEntity = true;
            break;
          }
          var url = entity.url || entityText;
          if (!url.match(/^https?:\/\//i)) {
            url = 'http://' + url;
          }
          var tgMeMatch;
          if (entity._ == 'messageEntityTextUrl') {
            url = 'tg://unsafe_url?url=' + encodeURIComponent(url);
          }
          else if ((tgMeMatch = url.match(/^https?:\/\/telegram\.me\/(.+)/))) {
            var path = tgMeMatch[1].split('/');
            switch (path[0]) {
              case 'joinchat':
                url = 'tg://join?invite=' + path[1];
                break;
              case 'addstickers':
                url = 'tg://addstickers?set=' + path[1];
                break;
              default:
                var domainQuery = path[0].split('?');
                url = 'tg://resolve?domain=' + domainQuery[0] + (domainQuery[1] ? '&' + domainQuery[1] : '');
            }
          }
          html.push(
            '<a href="',
            encodeEntities(url),
            '" target="_blank">',
            wrapRichNestedText(entityText, entity.nested, options),
            '</a>'
          );
          break;

        case 'messageEntityLinebreak':
          html.push(options.noLinebreaks ? ' ' : '<br/>');
          break;

        case 'messageEntityEmoji':
          html.push(
            '<span class="emoji emoji-',
            entity.coords.category,
            '-',
            (emojiIconSize * entity.coords.column),
            '-',
            (emojiIconSize * entity.coords.row),
            '" ',
            'title="', entity.title, '">',
            ':', entity.title, ':</span>'
          );
          emojiFound = true;
          break;

        case 'messageEntityBotCommand':
          if (options.noLinks || options.noCommands || contextExternal) {
            skipEntity = true;
            break;
          }
          var command = entityText.substr(1);
          var bot, atPos;
          if ((atPos = command.indexOf('@')) != -1) {
            bot = command.substr(atPos);
            command = command.substr(0, atPos);
          } else {
            bot = options.fromBot;
          }
          html.push(
            '<a href="',
            encodeEntities('tg://bot_command?command=' + encodeURIComponent(command) + (bot ? '&bot=' + encodeURIComponent(bot) : '')),
            '">',
            encodeEntities(entityText),
            '</a>'
          );
          break;

        case 'messageEntityBold':
          html.push(
            '<strong>',
            wrapRichNestedText(entityText, entity.nested, options),
            '</strong>'
          );
          break;

        case 'messageEntityItalic':
          html.push(
            '<em>',
            wrapRichNestedText(entityText, entity.nested, options),
            '</em>'
          );
          break;

        case 'messageEntityCode':
          html.push(
            '<code>',
            encodeEntities(entityText),
            '</code>'
          );
          break;

        case 'messageEntityPre':
          html.push(
            '<pre><code',(entity.language ? ' class="language-' + encodeEntities(entity.language) +'"' : ''),'>',
            encodeEntities(entityText),
            '</code></pre>'
          );
          break;

        default:
          skipEntity = true;
      }
      lastOffset = entity.offset + (skipEntity ? 0 : entity.length);
    }
    html.push(encodeEntities(text.substr(lastOffset)));

    text = $sanitize(html.join(''));

    if (emojiFound && !options.nested) {
      text = text.replace(/\ufe0f|&#65039;|&#65533;|&#8205;/g, '', text);
      text = text.replace(/<span class="emoji emoji-(\d)-(\d+)-(\d+)"(.+?)<\/span>/g,
                          '<span class="emoji emoji-spritesheet-$1" style="background-position: -$2px -$3px;" $4</span>');
    }

    return $sce.trustAs('html', text);
  }

  function checkBrackets(url) {
    var urlLength = url.length,
        urlOpenBrackets = url.split('(').length - 1,
        urlCloseBrackets = url.split(')').length - 1;

    while (urlCloseBrackets > urlOpenBrackets &&
           url.charAt(urlLength - 1) === ')') {
      url = url.substr(0, urlLength - 1);
      urlCloseBrackets--;
      urlLength--;
    }
    if (urlOpenBrackets > urlCloseBrackets) {
      url = url.replace(/\)+$/, '');
    }
    return url;
  }

  function wrapPlainText (text, options) {
    if (emojiSupported) {
      return text;
    }
    if (!text || !text.length) {
      return '';
    }

    options = options || {};

    text = text.replace(/\ufe0f/g, '', text);

    var match,
        raw = text,
        text = [],
        emojiTitle;

    while ((match = raw.match(fullRegExp))) {
      text.push(raw.substr(0, match.index));

      if (match[8]) {
        if ((emojiCode = emojiMap[match[8]]) &&
            (emojiTitle = emojiData[emojiCode][1][0])) {
          text.push(':' + emojiTitle + ':');
        } else {
          text.push(match[0]);
        }
      } else {
        text.push(match[0]);
      }
      raw = raw.substr(match.index + match[0].length);
    }
    text.push(raw);

    return text.join('');
  }

})