text: /* Copyright 2014 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.
   */
  
  const PDF_PATH = "../../web/compressed.tracemonkey-pldi-09.pdf";
  const PAGE_NUMBER = 1;
  const PAGE_SCALE = 1.5;
  const SVG_NS = "http://www.w3.org/2000/svg";
  
  pdfjsLib.GlobalWorkerOptions.workerSrc =
    "../../node_modules/pdfjs-dist/build/pdf.worker.js";
  
  function buildSVG(viewport, textContent) {
    // Building SVG with size of the viewport (for simplicity)
    const svg = document.createElementNS(SVG_NS, "svg:svg");
    svg.setAttribute("width", viewport.width + "px");
    svg.setAttribute("height", viewport.height + "px");
    // items are transformed to have 1px font size
    svg.setAttribute("font-size", 1);
  
    // processing all items
    textContent.items.forEach(function (textItem) {
      // we have to take in account viewport transform, which includes scale,
      // rotation and Y-axis flip, and not forgetting to flip text.
      const tx = pdfjsLib.Util.transform(
        pdfjsLib.Util.transform(viewport.transform, textItem.transform),
        [1, 0, 0, -1, 0, 0]
      );
      const style = textContent.styles[textItem.fontName];
      // adding text element
      const text = document.createElementNS(SVG_NS, "svg:text");
      text.setAttribute("transform", "matrix(" + tx.join(" ") + ")");
      text.setAttribute("font-family", style.fontFamily);
      text.textContent = textItem.str;
      svg.appendChild(text);
    });
    return svg;
  }
  
  async function pageLoaded() {
    // Loading document and page text content
    
    const loadingTask = pdfjsLib.getDocument({ url: PDF_PATH });
    const pdfDocument = await loadingTask.promise;
    const page = await pdfDocument.getPage(PAGE_NUMBER);
    const viewport = page.getViewport({ scale: PAGE_SCALE });
    const textContent = await page.getTextContent();
    // building SVG and adding that to the DOM
    const svg = buildSVG(viewport, textContent);
    document.getElementById("pageContainer").appendChild(svg);
  }
  
  document.addEventListener("DOMContentLoaded", function () {
    if (typeof pdfjsLib === "undefined") {
      // eslint-disable-next-line no-alert
      alert("Please build the pdfjs-dist library using\n  `gulp dist-install`");
      return;
    }
    pageLoaded();
  });
  