documenso/packages/signing/node-signpdf/dist/helpers/pdfkit/pdfobject.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true,
});
exports.default = void 0;

var _abstract_reference = _interopRequireDefault(require("./abstract_reference"));

function _interopRequireDefault(obj) {
  return obj && obj.__esModule ? obj : { default: obj };
}

/*
PDFObject by Devon Govett used below.
The class is part of pdfkit. See https://github.com/foliojs/pdfkit
LICENSE: MIT. Included in this folder.
Modifications may have been applied for the purposes of node-signpdf.
*/

/*
PDFObject - converts JavaScript types into their corresponding PDF types.
By Devon Govett
*/
const pad = (str, length) => (Array(length + 1).join("0") + str).slice(-length);

const escapableRe = /[\n\r\t\b\f()\\]/g;
const escapable = {
  "\n": "\\n",
  "\r": "\\r",
  "\t": "\\t",
  "\b": "\\b",
  "\f": "\\f",
  "\\": "\\\\",
  "(": "\\(",
  ")": "\\)",
}; // Convert little endian UTF-16 to big endian

const swapBytes = (buff) => buff.swap16();

class PDFObject {
  static convert(object, encryptFn = null) {
    // String literals are converted to the PDF name type
    if (typeof object === "string") {
      return `/${object}`; // String objects are converted to PDF strings (UTF-16)
    }

    if (object instanceof String) {
      let string = object; // Detect if this is a unicode string

      let isUnicode = false;

      for (let i = 0, end = string.length; i < end; i += 1) {
        if (string.charCodeAt(i) > 0x7f) {
          isUnicode = true;
          break;
        }
      } // If so, encode it as big endian UTF-16

      let stringBuffer;

      if (isUnicode) {
        stringBuffer = swapBytes(Buffer.from(`\ufeff${string}`, "utf16le"));
      } else {
        stringBuffer = Buffer.from(string, "ascii");
      } // Encrypt the string when necessary

      if (encryptFn) {
        string = encryptFn(stringBuffer).toString("binary");
      } else {
        string = stringBuffer.toString("binary");
      } // Escape characters as required by the spec

      string = string.replace(escapableRe, (c) => escapable[c]);
      return `(${string})`; // Buffers are converted to PDF hex strings
    }

    if (Buffer.isBuffer(object)) {
      return `<${object.toString("hex")}>`;
    }

    if (object instanceof _abstract_reference.default) {
      return object.toString();
    }

    if (object instanceof Date) {
      let string = `D:${pad(object.getUTCFullYear(), 4)}${pad(object.getUTCMonth() + 1, 2)}${pad(
        object.getUTCDate(),
        2
      )}${pad(object.getUTCHours(), 2)}${pad(object.getUTCMinutes(), 2)}${pad(
        object.getUTCSeconds(),
        2
      )}Z`; // Encrypt the string when necessary

      if (encryptFn) {
        string = encryptFn(Buffer.from(string, "ascii")).toString("binary"); // Escape characters as required by the spec

        string = string.replace(escapableRe, (c) => escapable[c]);
      }

      return `(${string})`;
    }

    if (Array.isArray(object)) {
      const items = object.map((e) => PDFObject.convert(e, encryptFn)).join(" ");
      return `[${items}]`;
    }

    if ({}.toString.call(object) === "[object Object]") {
      const out = ["<<"];
      let streamData; // @todo this can probably be refactored into a reduce

      Object.entries(object).forEach(([key, val]) => {
        let checkedValue = "";

        if (val.toString().indexOf("<<") !== -1) {
          checkedValue = val;
        } else {
          checkedValue = PDFObject.convert(val, encryptFn);
        }

        if (key === "stream") {
          streamData = `${key}\n${val}\nendstream`;
        } else {
          out.push(`/${key} ${checkedValue}`);
        }
      });
      out.push(">>");

      if (streamData) {
        out.push(streamData);
      }

      return out.join("\n");
    }

    if (typeof object === "number") {
      return PDFObject.number(object);
    }

    return `${object}`;
  }

  static number(n) {
    if (n > -1e21 && n < 1e21) {
      return Math.round(n * 1e6) / 1e6;
    }

    throw new Error(`unsupported number: ${n}`);
  }
}

exports.default = PDFObject;