pdf.js/src/shared/util.js

/* Copyright 2012 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import './compatibility';
import { ReadableStream } from './streams_polyfill';
import { URL } from './url_polyfill';

const IDENTITY_MATRIX = [1, 0, 0, 1, 0, 0];
const FONT_IDENTITY_MATRIX = [0.001, 0, 0, 0.001, 0, 0];

const NativeImageDecoding = {
  NONE: 'none',
  DECODE: 'decode',
  DISPLAY: 'display',
};

// Permission flags from Table 22, Section 7.6.3.2 of the PDF specification.
const PermissionFlag = {
  PRINT: 0x04,
  MODIFY_CONTENTS: 0x08,
  COPY: 0x10,
  MODIFY_ANNOTATIONS: 0x20,
  FILL_INTERACTIVE_FORMS: 0x100,
  COPY_FOR_ACCESSIBILITY: 0x200,
  ASSEMBLE: 0x400,
  PRINT_HIGH_QUALITY: 0x800,
};

const TextRenderingMode = {
  FILL: 0,
  STROKE: 1,
  FILL_STROKE: 2,
  INVISIBLE: 3,
  FILL_ADD_TO_PATH: 4,
  STROKE_ADD_TO_PATH: 5,
  FILL_STROKE_ADD_TO_PATH: 6,
  ADD_TO_PATH: 7,
  FILL_STROKE_MASK: 3,
  ADD_TO_PATH_FLAG: 4,
};

const ImageKind = {
  GRAYSCALE_1BPP: 1,
  RGB_24BPP: 2,
  RGBA_32BPP: 3,
};

const AnnotationType = {
  TEXT: 1,
  LINK: 2,
  FREETEXT: 3,
  LINE: 4,
  SQUARE: 5,
  CIRCLE: 6,
  POLYGON: 7,
  POLYLINE: 8,
  HIGHLIGHT: 9,
  UNDERLINE: 10,
  SQUIGGLY: 11,
  STRIKEOUT: 12,
  STAMP: 13,
  CARET: 14,
  INK: 15,
  POPUP: 16,
  FILEATTACHMENT: 17,
  SOUND: 18,
  MOVIE: 19,
  WIDGET: 20,
  SCREEN: 21,
  PRINTERMARK: 22,
  TRAPNET: 23,
  WATERMARK: 24,
  THREED: 25,
  REDACT: 26,
};

const AnnotationFlag = {
  INVISIBLE: 0x01,
  HIDDEN: 0x02,
  PRINT: 0x04,
  NOZOOM: 0x08,
  NOROTATE: 0x10,
  NOVIEW: 0x20,
  READONLY: 0x40,
  LOCKED: 0x80,
  TOGGLENOVIEW: 0x100,
  LOCKEDCONTENTS: 0x200,
};

const AnnotationFieldFlag = {
  READONLY: 0x0000001,
  REQUIRED: 0x0000002,
  NOEXPORT: 0x0000004,
  MULTILINE: 0x0001000,
  PASSWORD: 0x0002000,
  NOTOGGLETOOFF: 0x0004000,
  RADIO: 0x0008000,
  PUSHBUTTON: 0x0010000,
  COMBO: 0x0020000,
  EDIT: 0x0040000,
  SORT: 0x0080000,
  FILESELECT: 0x0100000,
  MULTISELECT: 0x0200000,
  DONOTSPELLCHECK: 0x0400000,
  DONOTSCROLL: 0x0800000,
  COMB: 0x1000000,
  RICHTEXT: 0x2000000,
  RADIOSINUNISON: 0x2000000,
  COMMITONSELCHANGE: 0x4000000,
};

const AnnotationBorderStyleType = {
  SOLID: 1,
  DASHED: 2,
  BEVELED: 3,
  INSET: 4,
  UNDERLINE: 5,
};

const StreamType = {
  UNKNOWN: 0,
  FLATE: 1,
  LZW: 2,
  DCT: 3,
  JPX: 4,
  JBIG: 5,
  A85: 6,
  AHX: 7,
  CCF: 8,
  RL: 9,
};

const FontType = {
  UNKNOWN: 0,
  TYPE1: 1,
  TYPE1C: 2,
  CIDFONTTYPE0: 3,
  CIDFONTTYPE0C: 4,
  TRUETYPE: 5,
  CIDFONTTYPE2: 6,
  TYPE3: 7,
  OPENTYPE: 8,
  TYPE0: 9,
  MMTYPE1: 10,
};

const VerbosityLevel = {
  ERRORS: 0,
  WARNINGS: 1,
  INFOS: 5,
};

const CMapCompressionType = {
  NONE: 0,
  BINARY: 1,
  STREAM: 2,
};

// All the possible operations for an operator list.
const OPS = {
  // Intentionally start from 1 so it is easy to spot bad operators that will be
  // 0's.
  dependency: 1,
  setLineWidth: 2,
  setLineCap: 3,
  setLineJoin: 4,
  setMiterLimit: 5,
  setDash: 6,
  setRenderingIntent: 7,
  setFlatness: 8,
  setGState: 9,
  save: 10,
  restore: 11,
  transform: 12,
  moveTo: 13,
  lineTo: 14,
  curveTo: 15,
  curveTo2: 16,
  curveTo3: 17,
  closePath: 18,
  rectangle: 19,
  stroke: 20,
  closeStroke: 21,
  fill: 22,
  eoFill: 23,
  fillStroke: 24,
  eoFillStroke: 25,
  closeFillStroke: 26,
  closeEOFillStroke: 27,
  endPath: 28,
  clip: 29,
  eoClip: 30,
  beginText: 31,
  endText: 32,
  setCharSpacing: 33,
  setWordSpacing: 34,
  setHScale: 35,
  setLeading: 36,
  setFont: 37,
  setTextRenderingMode: 38,
  setTextRise: 39,
  moveText: 40,
  setLeadingMoveText: 41,
  setTextMatrix: 42,
  nextLine: 43,
  showText: 44,
  showSpacedText: 45,
  nextLineShowText: 46,
  nextLineSetSpacingShowText: 47,
  setCharWidth: 48,
  setCharWidthAndBounds: 49,
  setStrokeColorSpace: 50,
  setFillColorSpace: 51,
  setStrokeColor: 52,
  setStrokeColorN: 53,
  setFillColor: 54,
  setFillColorN: 55,
  setStrokeGray: 56,
  setFillGray: 57,
  setStrokeRGBColor: 58,
  setFillRGBColor: 59,
  setStrokeCMYKColor: 60,
  setFillCMYKColor: 61,
  shadingFill: 62,
  beginInlineImage: 63,
  beginImageData: 64,
  endInlineImage: 65,
  paintXObject: 66,
  markPoint: 67,
  markPointProps: 68,
  beginMarkedContent: 69,
  beginMarkedContentProps: 70,
  endMarkedContent: 71,
  beginCompat: 72,
  endCompat: 73,
  paintFormXObjectBegin: 74,
  paintFormXObjectEnd: 75,
  beginGroup: 76,
  endGroup: 77,
  beginAnnotations: 78,
  endAnnotations: 79,
  beginAnnotation: 80,
  endAnnotation: 81,
  paintJpegXObject: 82,
  paintImageMaskXObject: 83,
  paintImageMaskXObjectGroup: 84,
  paintImageXObject: 85,
  paintInlineImageXObject: 86,
  paintInlineImageXObjectGroup: 87,
  paintImageXObjectRepeat: 88,
  paintImageMaskXObjectRepeat: 89,
  paintSolidColorImageMask: 90,
  constructPath: 91,
};

const UNSUPPORTED_FEATURES = {
  unknown: 'unknown',
  forms: 'forms',
  javaScript: 'javaScript',
  smask: 'smask',
  shadingPattern: 'shadingPattern',
  font: 'font',
};

const PasswordResponses = {
  NEED_PASSWORD: 1,
  INCORRECT_PASSWORD: 2,
};

let verbosity = VerbosityLevel.WARNINGS;

function setVerbosityLevel(level) {
  if (Number.isInteger(level)) {
    verbosity = level;
  }
}

function getVerbosityLevel() {
  return verbosity;
}

// A notice for devs. These are good for things that are helpful to devs, such
// as warning that Workers were disabled, which is important to devs but not
// end users.
function info(msg) {
  if (verbosity >= VerbosityLevel.INFOS) {
    console.log('Info: ' + msg);
  }
}

// Non-fatal warnings.
function warn(msg) {
  if (verbosity >= VerbosityLevel.WARNINGS) {
    console.log('Warning: ' + msg);
  }
}

// Deprecated API function -- display regardless of the `verbosity` setting.
function deprecated(details) {
  console.log('Deprecated API usage: ' + details);
}

function unreachable(msg) {
  throw new Error(msg);
}

function assert(cond, msg) {
  if (!cond) {
    unreachable(msg);
  }
}

// Checks if URLs have the same origin. For non-HTTP based URLs, returns false.
function isSameOrigin(baseUrl, otherUrl) {
  try {
    var base = new URL(baseUrl);
    if (!base.origin || base.origin === 'null') {
      return false; // non-HTTP url
    }
  } catch (e) {
    return false;
  }

  var other = new URL(otherUrl, base);
  return base.origin === other.origin;
}

// Checks if URLs use one of the whitelisted protocols, e.g. to avoid XSS.
function _isValidProtocol(url) {
  if (!url) {
    return false;
  }
  switch (url.protocol) {
    case 'http:':
    case 'https:':
    case 'ftp:':
    case 'mailto:':
    case 'tel:':
      return true;
    default:
      return false;
  }
}

/**
 * Attempts to create a valid absolute URL.
 *
 * @param {URL|string} url - An absolute, or relative, URL.
 * @param {URL|string} baseUrl - An absolute URL.
 * @returns Either a valid {URL}, or `null` otherwise.
 */
function createValidAbsoluteUrl(url, baseUrl) {
  if (!url) {
    return null;
  }
  try {
    var absoluteUrl = baseUrl ? new URL(url, baseUrl) : new URL(url);
    if (_isValidProtocol(absoluteUrl)) {
      return absoluteUrl;
    }
  } catch (ex) { /* `new URL()` will throw on incorrect data. */ }
  return null;
}

function shadow(obj, prop, value) {
  Object.defineProperty(obj, prop, { value,
                                     enumerable: true,
                                     configurable: true,
                                     writable: false, });
  return value;
}

function getLookupTableFactory(initializer) {
  var lookup;
  return function () {
    if (initializer) {
      lookup = Object.create(null);
      initializer(lookup);
      initializer = null;
    }
    return lookup;
  };
}

var PasswordException = (function PasswordExceptionClosure() {
  function PasswordException(msg, code) {
    this.name = 'PasswordException';
    this.message = msg;
    this.code = code;
  }

  PasswordException.prototype = new Error();
  PasswordException.constructor = PasswordException;

  return PasswordException;
})();

var UnknownErrorException = (function UnknownErrorExceptionClosure() {
  function UnknownErrorException(msg, details) {
    this.name = 'UnknownErrorException';
    this.message = msg;
    this.details = details;
  }

  UnknownErrorException.prototype = new Error();
  UnknownErrorException.constructor = UnknownErrorException;

  return UnknownErrorException;
})();

var InvalidPDFException = (function InvalidPDFExceptionClosure() {
  function InvalidPDFException(msg) {
    this.name = 'InvalidPDFException';
    this.message = msg;
  }

  InvalidPDFException.prototype = new Error();
  InvalidPDFException.constructor = InvalidPDFException;

  return InvalidPDFException;
})();

var MissingPDFException = (function MissingPDFExceptionClosure() {
  function MissingPDFException(msg) {
    this.name = 'MissingPDFException';
    this.message = msg;
  }

  MissingPDFException.prototype = new Error();
  MissingPDFException.constructor = MissingPDFException;

  return MissingPDFException;
})();

var UnexpectedResponseException =
    (function UnexpectedResponseExceptionClosure() {
  function UnexpectedResponseException(msg, status) {
    this.name = 'UnexpectedResponseException';
    this.message = msg;
    this.status = status;
  }

  UnexpectedResponseException.prototype = new Error();
  UnexpectedResponseException.constructor = UnexpectedResponseException;

  return UnexpectedResponseException;
})();

var MissingDataException = (function MissingDataExceptionClosure() {
  function MissingDataException(begin, end) {
    this.begin = begin;
    this.end = end;
    this.message = 'Missing data [' + begin + ', ' + end + ')';
  }

  MissingDataException.prototype = new Error();
  MissingDataException.prototype.name = 'MissingDataException';
  MissingDataException.constructor = MissingDataException;

  return MissingDataException;
})();

const XRefEntryException = (function XRefEntryExceptionClosure() {
  function XRefEntryException(msg) {
    this.message = msg;
  }

  XRefEntryException.prototype = new Error();
  XRefEntryException.prototype.name = 'XRefEntryException';
  XRefEntryException.constructor = XRefEntryException;

  return XRefEntryException;
})();

var XRefParseException = (function XRefParseExceptionClosure() {
  function XRefParseException(msg) {
    this.message = msg;
  }

  XRefParseException.prototype = new Error();
  XRefParseException.prototype.name = 'XRefParseException';
  XRefParseException.constructor = XRefParseException;

  return XRefParseException;
})();

/**
 * Error caused during parsing PDF data.
 */
let FormatError = (function FormatErrorClosure() {
  function FormatError(msg) {
    this.message = msg;
  }

  FormatError.prototype = new Error();
  FormatError.prototype.name = 'FormatError';
  FormatError.constructor = FormatError;

  return FormatError;
})();

/**
 * Error used to indicate task cancellation.
 */
let AbortException = (function AbortExceptionClosure() {
  function AbortException(msg) {
    this.name = 'AbortException';
    this.message = msg;
  }

  AbortException.prototype = new Error();
  AbortException.constructor = AbortException;

  return AbortException;
})();

var NullCharactersRegExp = /\x00/g;

function removeNullCharacters(str) {
  if (typeof str !== 'string') {
    warn('The argument for removeNullCharacters must be a string.');
    return str;
  }
  return str.replace(NullCharactersRegExp, '');
}

function bytesToString(bytes) {
  assert(bytes !== null && typeof bytes === 'object' &&
         bytes.length !== undefined, 'Invalid argument for bytesToString');
  var length = bytes.length;
  var MAX_ARGUMENT_COUNT = 8192;
  if (length < MAX_ARGUMENT_COUNT) {
    return String.fromCharCode.apply(null, bytes);
  }
  var strBuf = [];
  for (var i = 0; i < length; i += MAX_ARGUMENT_COUNT) {
    var chunkEnd = Math.min(i + MAX_ARGUMENT_COUNT, length);
    var chunk = bytes.subarray(i, chunkEnd);
    strBuf.push(String.fromCharCode.apply(null, chunk));
  }
  return strBuf.join('');
}

function stringToBytes(str) {
  assert(typeof str === 'string', 'Invalid argument for stringToBytes');
  var length = str.length;
  var bytes = new Uint8Array(length);
  for (var i = 0; i < length; ++i) {
    bytes[i] = str.charCodeAt(i) & 0xFF;
  }
  return bytes;
}

/**
 * Gets length of the array (Array, Uint8Array, or string) in bytes.
 * @param {Array|Uint8Array|string} arr
 * @returns {number}
 */
function arrayByteLength(arr) {
  if (arr.length !== undefined) {
    return arr.length;
  }
  assert(arr.byteLength !== undefined);
  return arr.byteLength;
}

/**
 * Combines array items (arrays) into single Uint8Array object.
 * @param {Array} arr - the array of the arrays (Array, Uint8Array, or string).
 * @returns {Uint8Array}
 */
function arraysToBytes(arr) {
  // Shortcut: if first and only item is Uint8Array, return it.
  if (arr.length === 1 && (arr[0] instanceof Uint8Array)) {
    return arr[0];
  }
  var resultLength = 0;
  var i, ii = arr.length;
  var item, itemLength;
  for (i = 0; i < ii; i++) {
    item = arr[i];
    itemLength = arrayByteLength(item);
    resultLength += itemLength;
  }
  var pos = 0;
  var data = new Uint8Array(resultLength);
  for (i = 0; i < ii; i++) {
    item = arr[i];
    if (!(item instanceof Uint8Array)) {
      if (typeof item === 'string') {
        item = stringToBytes(item);
      } else {
        item = new Uint8Array(item);
      }
    }
    itemLength = item.byteLength;
    data.set(item, pos);
    pos += itemLength;
  }
  return data;
}

function string32(value) {
  return String.fromCharCode((value >> 24) & 0xff, (value >> 16) & 0xff,
                             (value >> 8) & 0xff, value & 0xff);
}

// Calculate the base 2 logarithm of the number `x`. This differs from the
// native function in the sense that it returns the ceiling value and that it
// returns 0 instead of `Infinity`/`NaN` for `x` values smaller than/equal to 0.
function log2(x) {
  if (x <= 0) {
    return 0;
  }
  return Math.ceil(Math.log2(x));
}

function readInt8(data, start) {
  return (data[start] << 24) >> 24;
}

function readUint16(data, offset) {
  return (data[offset] << 8) | data[offset + 1];
}

function readUint32(data, offset) {
  return ((data[offset] << 24) | (data[offset + 1] << 16) |
         (data[offset + 2] << 8) | data[offset + 3]) >>> 0;
}

// Lazy test the endianness of the platform
// NOTE: This will be 'true' for simulated TypedArrays
function isLittleEndian() {
  var buffer8 = new Uint8Array(4);
  buffer8[0] = 1;
  var view32 = new Uint32Array(buffer8.buffer, 0, 1);
  return (view32[0] === 1);
}

// Checks if it's possible to eval JS expressions.
function isEvalSupported() {
  try {
    new Function(''); // eslint-disable-line no-new, no-new-func
    return true;
  } catch (e) {
    return false;
  }
}

/**
 * Get the value of an inheritable property.
 *
 * If the PDF specification explicitly lists a property in a dictionary as
 * inheritable, then the value of the property may be present in the dictionary
 * itself or in one or more parents of the dictionary.
 *
 * If the key is not found in the tree, `undefined` is returned. Otherwise,
 * the value for the key is returned or, if `stopWhenFound` is `false`, a list
 * of values is returned. To avoid infinite loops, the traversal is stopped when
 * the loop limit is reached.
 *
 * @param {Dict} dict - Dictionary from where to start the traversal.
 * @param {string} key - The key of the property to find the value for.
 * @param {boolean} getArray - Whether or not the value should be fetched as an
 *   array. The default value is `false`.
 * @param {boolean} stopWhenFound - Whether or not to stop the traversal when
 *   the key is found. If set to `false`, we always walk up the entire parent
 *   chain, for example to be able to find `\Resources` placed on multiple
 *   levels of the tree. The default value is `true`.
 */
function getInheritableProperty({ dict, key, getArray = false,
                                  stopWhenFound = true, }) {
  const LOOP_LIMIT = 100;
  let loopCount = 0;
  let values;

  while (dict) {
    const value = getArray ? dict.getArray(key) : dict.get(key);
    if (value !== undefined) {
      if (stopWhenFound) {
        return value;
      }
      if (!values) {
        values = [];
      }
      values.push(value);
    }
    if (++loopCount > LOOP_LIMIT) {
      warn(`getInheritableProperty: maximum loop count exceeded for "${key}"`);
      break;
    }
    dict = dict.get('Parent');
  }
  return values;
}

var Util = (function UtilClosure() {
  function Util() {}

  var rgbBuf = ['rgb(', 0, ',', 0, ',', 0, ')'];

  // makeCssRgb() can be called thousands of times. Using |rgbBuf| avoids
  // creating many intermediate strings.
  Util.makeCssRgb = function Util_makeCssRgb(r, g, b) {
    rgbBuf[1] = r;
    rgbBuf[3] = g;
    rgbBuf[5] = b;
    return rgbBuf.join('');
  };

  // Concatenates two transformation matrices together and returns the result.
  Util.transform = function Util_transform(m1, m2) {
    return [
      m1[0] * m2[0] + m1[2] * m2[1],
      m1[1] * m2[0] + m1[3] * m2[1],
      m1[0] * m2[2] + m1[2] * m2[3],
      m1[1] * m2[2] + m1[3] * m2[3],
      m1[0] * m2[4] + m1[2] * m2[5] + m1[4],
      m1[1] * m2[4] + m1[3] * m2[5] + m1[5]
    ];
  };

  // For 2d affine transforms
  Util.applyTransform = function Util_applyTransform(p, m) {
    var xt = p[0] * m[0] + p[1] * m[2] + m[4];
    var yt = p[0] * m[1] + p[1] * m[3] + m[5];
    return [xt, yt];
  };

  Util.applyInverseTransform = function Util_applyInverseTransform(p, m) {
    var d = m[0] * m[3] - m[1] * m[2];
    var xt = (p[0] * m[3] - p[1] * m[2] + m[2] * m[5] - m[4] * m[3]) / d;
    var yt = (-p[0] * m[1] + p[1] * m[0] + m[4] * m[1] - m[5] * m[0]) / d;
    return [xt, yt];
  };

  // Applies the transform to the rectangle and finds the minimum axially
  // aligned bounding box.
  Util.getAxialAlignedBoundingBox =
    function Util_getAxialAlignedBoundingBox(r, m) {

    var p1 = Util.applyTransform(r, m);
    var p2 = Util.applyTransform(r.slice(2, 4), m);
    var p3 = Util.applyTransform([r[0], r[3]], m);
    var p4 = Util.applyTransform([r[2], r[1]], m);
    return [
      Math.min(p1[0], p2[0], p3[0], p4[0]),
      Math.min(p1[1], p2[1], p3[1], p4[1]),
      Math.max(p1[0], p2[0], p3[0], p4[0]),
      Math.max(p1[1], p2[1], p3[1], p4[1])
    ];
  };

  Util.inverseTransform = function Util_inverseTransform(m) {
    var d = m[0] * m[3] - m[1] * m[2];
    return [m[3] / d, -m[1] / d, -m[2] / d, m[0] / d,
      (m[2] * m[5] - m[4] * m[3]) / d, (m[4] * m[1] - m[5] * m[0]) / d];
  };

  // Apply a generic 3d matrix M on a 3-vector v:
  //   | a b c |   | X |
  //   | d e f | x | Y |
  //   | g h i |   | Z |
  // M is assumed to be serialized as [a,b,c,d,e,f,g,h,i],
  // with v as [X,Y,Z]
  Util.apply3dTransform = function Util_apply3dTransform(m, v) {
    return [
      m[0] * v[0] + m[1] * v[1] + m[2] * v[2],
      m[3] * v[0] + m[4] * v[1] + m[5] * v[2],
      m[6] * v[0] + m[7] * v[1] + m[8] * v[2]
    ];
  };

  // This calculation uses Singular Value Decomposition.
  // The SVD can be represented with formula A = USV. We are interested in the
  // matrix S here because it represents the scale values.
  Util.singularValueDecompose2dScale =
    function Util_singularValueDecompose2dScale(m) {

    var transpose = [m[0], m[2], m[1], m[3]];

    // Multiply matrix m with its transpose.
    var a = m[0] * transpose[0] + m[1] * transpose[2];
    var b = m[0] * transpose[1] + m[1] * transpose[3];
    var c = m[2] * transpose[0] + m[3] * transpose[2];
    var d = m[2] * transpose[1] + m[3] * transpose[3];

    // Solve the second degree polynomial to get roots.
    var first = (a + d) / 2;
    var second = Math.sqrt((a + d) * (a + d) - 4 * (a * d - c * b)) / 2;
    var sx = first + second || 1;
    var sy = first - second || 1;

    // Scale values are the square roots of the eigenvalues.
    return [Math.sqrt(sx), Math.sqrt(sy)];
  };

  // Normalize rectangle rect=[x1, y1, x2, y2] so that (x1,y1) < (x2,y2)
  // For coordinate systems whose origin lies in the bottom-left, this
  // means normalization to (BL,TR) ordering. For systems with origin in the
  // top-left, this means (TL,BR) ordering.
  Util.normalizeRect = function Util_normalizeRect(rect) {
    var r = rect.slice(0); // clone rect
    if (rect[0] > rect[2]) {
      r[0] = rect[2];
      r[2] = rect[0];
    }
    if (rect[1] > rect[3]) {
      r[1] = rect[3];
      r[3] = rect[1];
    }
    return r;
  };

  // Returns a rectangle [x1, y1, x2, y2] corresponding to the
  // intersection of rect1 and rect2. If no intersection, returns 'false'
  // The rectangle coordinates of rect1, rect2 should be [x1, y1, x2, y2]
  Util.intersect = function Util_intersect(rect1, rect2) {
    function compare(a, b) {
      return a - b;
    }

    // Order points along the axes
    var orderedX = [rect1[0], rect1[2], rect2[0], rect2[2]].sort(compare),
        orderedY = [rect1[1], rect1[3], rect2[1], rect2[3]].sort(compare),
        result = [];

    rect1 = Util.normalizeRect(rect1);
    rect2 = Util.normalizeRect(rect2);

    // X: first and second points belong to different rectangles?
    if ((orderedX[0] === rect1[0] && orderedX[1] === rect2[0]) ||
        (orderedX[0] === rect2[0] && orderedX[1] === rect1[0])) {
      // Intersection must be between second and third points
      result[0] = orderedX[1];
      result[2] = orderedX[2];
    } else {
      return false;
    }

    // Y: first and second points belong to different rectangles?
    if ((orderedY[0] === rect1[1] && orderedY[1] === rect2[1]) ||
        (orderedY[0] === rect2[1] && orderedY[1] === rect1[1])) {
      // Intersection must be between second and third points
      result[1] = orderedY[1];
      result[3] = orderedY[2];
    } else {
      return false;
    }

    return result;
  };

  return Util;
})();

const ROMAN_NUMBER_MAP = [
  '', 'C', 'CC', 'CCC', 'CD', 'D', 'DC', 'DCC', 'DCCC', 'CM',
  '', 'X', 'XX', 'XXX', 'XL', 'L', 'LX', 'LXX', 'LXXX', 'XC',
  '', 'I', 'II', 'III', 'IV', 'V', 'VI', 'VII', 'VIII', 'IX'
];

/**
 * Converts positive integers to (upper case) Roman numerals.
 * @param {integer} number - The number that should be converted.
 * @param {boolean} lowerCase - Indicates if the result should be converted
 *   to lower case letters. The default value is `false`.
 * @return {string} The resulting Roman number.
 */
function toRomanNumerals(number, lowerCase = false) {
  assert(Number.isInteger(number) && number > 0,
         'The number should be a positive integer.');
  let pos, romanBuf = [];
  // Thousands
  while (number >= 1000) {
    number -= 1000;
    romanBuf.push('M');
  }
  // Hundreds
  pos = (number / 100) | 0;
  number %= 100;
  romanBuf.push(ROMAN_NUMBER_MAP[pos]);
  // Tens
  pos = (number / 10) | 0;
  number %= 10;
  romanBuf.push(ROMAN_NUMBER_MAP[10 + pos]);
  // Ones
  romanBuf.push(ROMAN_NUMBER_MAP[20 + number]);

  const romanStr = romanBuf.join('');
  return (lowerCase ? romanStr.toLowerCase() : romanStr);
}

const PDFStringTranslateTable = [
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0x2D8, 0x2C7, 0x2C6, 0x2D9, 0x2DD, 0x2DB, 0x2DA, 0x2DC, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x2022, 0x2020, 0x2021, 0x2026, 0x2014,
  0x2013, 0x192, 0x2044, 0x2039, 0x203A, 0x2212, 0x2030, 0x201E, 0x201C,
  0x201D, 0x2018, 0x2019, 0x201A, 0x2122, 0xFB01, 0xFB02, 0x141, 0x152, 0x160,
  0x178, 0x17D, 0x131, 0x142, 0x153, 0x161, 0x17E, 0, 0x20AC
];

function stringToPDFString(str) {
  var i, n = str.length, strBuf = [];
  if (str[0] === '\xFE' && str[1] === '\xFF') {
    // UTF16BE BOM
    for (i = 2; i < n; i += 2) {
      strBuf.push(String.fromCharCode(
        (str.charCodeAt(i) << 8) | str.charCodeAt(i + 1)));
    }
  } else {
    for (i = 0; i < n; ++i) {
      var code = PDFStringTranslateTable[str.charCodeAt(i)];
      strBuf.push(code ? String.fromCharCode(code) : str.charAt(i));
    }
  }
  return strBuf.join('');
}

function stringToUTF8String(str) {
  return decodeURIComponent(escape(str));
}

function utf8StringToString(str) {
  return unescape(encodeURIComponent(str));
}

function isEmptyObj(obj) {
  for (var key in obj) {
    return false;
  }
  return true;
}

function isBool(v) {
  return typeof v === 'boolean';
}

function isNum(v) {
  return typeof v === 'number';
}

function isString(v) {
  return typeof v === 'string';
}

function isArrayBuffer(v) {
  return typeof v === 'object' && v !== null && v.byteLength !== undefined;
}

// Checks if ch is one of the following characters: SPACE, TAB, CR or LF.
function isSpace(ch) {
  return (ch === 0x20 || ch === 0x09 || ch === 0x0D || ch === 0x0A);
}

/**
 * Promise Capability object.
 *
 * @typedef {Object} PromiseCapability
 * @property {Promise} promise - A promise object.
 * @property {function} resolve - Fulfills the promise.
 * @property {function} reject - Rejects the promise.
 */

/**
 * Creates a promise capability object.
 * @alias createPromiseCapability
 *
 * @return {PromiseCapability} A capability object contains:
 * - a Promise, resolve and reject methods.
 */
function createPromiseCapability() {
  var capability = {};
  capability.promise = new Promise(function (resolve, reject) {
    capability.resolve = resolve;
    capability.reject = reject;
  });
  return capability;
}

var createObjectURL = (function createObjectURLClosure() {
  // Blob/createObjectURL is not available, falling back to data schema.
  var digits =
    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';

  return function createObjectURL(data, contentType, forceDataSchema = false) {
    if (!forceDataSchema && URL.createObjectURL) {
      const blob = new Blob([data], { type: contentType, });
      return URL.createObjectURL(blob);
    }

    var buffer = 'data:' + contentType + ';base64,';
    for (var i = 0, ii = data.length; i < ii; i += 3) {
      var b1 = data[i] & 0xFF;
      var b2 = data[i + 1] & 0xFF;
      var b3 = data[i + 2] & 0xFF;
      var d1 = b1 >> 2, d2 = ((b1 & 3) << 4) | (b2 >> 4);
      var d3 = i + 1 < ii ? ((b2 & 0xF) << 2) | (b3 >> 6) : 64;
      var d4 = i + 2 < ii ? (b3 & 0x3F) : 64;
      buffer += digits[d1] + digits[d2] + digits[d3] + digits[d4];
    }
    return buffer;
  };
})();

export {
  FONT_IDENTITY_MATRIX,
  IDENTITY_MATRIX,
  OPS,
  VerbosityLevel,
  UNSUPPORTED_FEATURES,
  AnnotationBorderStyleType,
  AnnotationFieldFlag,
  AnnotationFlag,
  AnnotationType,
  FontType,
  ImageKind,
  CMapCompressionType,
  AbortException,
  InvalidPDFException,
  MissingDataException,
  MissingPDFException,
  NativeImageDecoding,
  PasswordException,
  PasswordResponses,
  PermissionFlag,
  StreamType,
  TextRenderingMode,
  UnexpectedResponseException,
  UnknownErrorException,
  Util,
  toRomanNumerals,
  XRefEntryException,
  XRefParseException,
  FormatError,
  arrayByteLength,
  arraysToBytes,
  assert,
  bytesToString,
  createPromiseCapability,
  createObjectURL,
  deprecated,
  getInheritableProperty,
  getLookupTableFactory,
  getVerbosityLevel,
  info,
  isArrayBuffer,
  isBool,
  isEmptyObj,
  isNum,
  isString,
  isSpace,
  isSameOrigin,
  createValidAbsoluteUrl,
  isLittleEndian,
  isEvalSupported,
  log2,
  readInt8,
  readUint16,
  readUint32,
  removeNullCharacters,
  ReadableStream,
  URL,
  setVerbosityLevel,
  shadow,
  string32,
  stringToBytes,
  stringToPDFString,
  stringToUTF8String,
  utf8StringToString,
  warn,
  unreachable,
};