Refactor pdf logic

src/book.js

@@ -319,23 +319,21 @@ export class Book {
       const generateSignatures = this.print_file != 'aggregated';
       let aggregatePdf0, aggregatePdf1;
       if (generateAggregate) {
-          aggregatePdf0 = await PDFDocument.create();
-          aggregatePdf1 = this.duplex ? null : await PDFDocument.create();
+        aggregatePdf0 = await PDFDocument.create();
+        aggregatePdf1 = this.duplex ? null : await PDFDocument.create();
       }
       const forLoop = async () => {
-
         for (let i = 0; i < this.rearrangedpages.length; i++) {
           const signature = this.rearrangedpages[i];
           console.log(signature);
           const sigName = `${this.filename}_signature${i}`;
           const [sigFront, sigBack] = await this.createSignatures({
             pageIndexDetails: signature,
-            fileList: this.filelist,
           });
 
           if (this.duplex) {
             // collate
-            const sig = this.collatePages(sigFront, sigBack)
+            const sig = await this.collatePages(sigFront, sigBack);
 
             if (generateSignatures) {
               await sig.save().then((pdfBytes) => {
@@ -344,10 +342,9 @@ export class Book {
             }
 
             if (generateAggregate) {
-              const copiedPages = await aggregatePdf0.embedPages(sig, sig.getPageIndices());
+              const copiedPages = await aggregatePdf0.copyPages(sig, sig.getPageIndices());
               copiedPages.forEach((page) => aggregatePdf0.addPage(page));
             }
-
           } else {
             if (generateSignatures) {
               await sigFront.save().then((pdfBytes) => {
@@ -359,15 +356,19 @@ export class Book {
             }
 
             if (generateAggregate) {
-              const copiedPagesFront = await aggregatePdf0.embedPages(sigFront, sigFront.getPageIndices());
+              const copiedPagesFront = await aggregatePdf0.copyPages(
+                sigFront,
+                sigFront.getPageIndices()
+              );
               copiedPagesFront.forEach((page) => aggregatePdf0.addPage(page));
 
-              const copiedPagesBack = await aggregatePdf1.embedPages(sigBack, sigBack.getPageIndices());
+              const copiedPagesBack = await aggregatePdf1.copyPages(
+                sigBack,
+                sigBack.getPageIndices()
+              );
               copiedPagesBack.forEach((page) => aggregatePdf1.addPage(page));
             }
-
           }
-
         }
       };
       await forLoop();
@@ -460,22 +461,27 @@ export class Book {
     return [newPdf, embeddedPages];
   }
 
-  async addPdf(destPdf, sourcePdf) {
-    await mergedPdf.copyPages(pdfA, pdfA.getPageIndices());
-      copiedPagesA.forEach((page) => mergedPdf.addPage(page))
-  }
+  async collatePages(pdfA, pdfB) {
+    const mergedPdf = await PDFDocument.create();
+    const pageCount = Math.max(pdfA.getPageCount(), pdfB.getPageCount());
+    for (let i = 0; i < pageCount; i++) {
+      const pageA = pdfA.getPage(i);
+      if (pageA) mergedPdf.addPage((await mergedPdf.copyPages(pdfA, [i]))[0]);
+
+      const pageB = pdfB.getPage(i);
+      if (pageB) mergedPdf.addPage((await mergedPdf.copyPages(pdfB, [i]))[0]);
+    }
 
+    return mergedPdf;
+  }
   /**
    * Part of the Classic (non-Wacky) flow. Called by [createsignatures].
    *   (conditionally) populates the destPdf and (conditionally) generates the outname PDF
    *
    * @param {Object} config - object /w the following parameters:
-   * @param {string|null} config.outname : name of pdf added to ongoing zip file. Ex: 'signature1duplex.pdf' (or null if no signature file needed)
    * @param {PageInfo[]} config.pageList : objects that contain 3 values: { isSigStart: boolean, isSigEnd: boolean, info: either the page number or 'b'}
    * @param {boolean} config.back : is 'back' of page  (boolean)
    * @param {boolean} config.alt : alternate pages (boolean)
-   * @param config.destPdf : PDF to write to, in addition to PDF created w/ `outname` (or null)
-   * @param config.providedPages : pages already embedded in the `destPdf` to assemble in addition (or null)
    * @return reference to the new PDF created
    */
   async writepages(config) {
@@ -600,24 +606,21 @@ export class Book {
    * PDF builder base function for Classic (non-Wacky) layouts. Called by [createoutputfiles]
    *
    * @param {Object} config
-   * @param {PageInfo[][]|PageInfo[]} config.pageIndexDetails : a nested list of objects.
-   * @param config.embeddedPages : list of lists of embedded pages from source document ( [0] for duplex & front, [1] for backs -- value is null if no aggregate printing enabled)
-   * @param {string} config.id : string dentifier for signature file name (null if no signature files to be generated)
-   * @param {string[]} config.fileList : list of filenames for sig filename to be added to (modifies list)
+   * @param {PageInfo[][]} config.pageIndexDetails : a nested list of objects.
    */
   async createSignatures(config) {
     const pages = config.pageIndexDetails;
-      const pdfFront = await this.writepages({
-        pageList: pages[0],
-        back: false,
-        alt: false,
-      });
-      const pdfBack = await this.writepages({
-        pageList: pages[1],
-        back: true,
-        alt: false,
-      });
-      return [pdfFront, pdfBack];
+    const pdfFront = await this.writepages({
+      pageList: pages[0],
+      back: false,
+      alt: false,
+    });
+    const pdfBack = await this.writepages({
+      pageList: pages[1],
+      back: true,
+      alt: false,
+    });
+    return [pdfFront, pdfBack];
   }
 
   bundleSettings() {
@@ -626,7 +629,7 @@ export class Book {
       `Imposer settings: ${JSON.stringify(currentConfig, null, 2)}` +
       '\n\n' +
       `Link to the imposer with these settings: ${window.location.href}`;
-    this.zip?.file('settings.txt', settings);
+    this.zip.file('settings.txt', settings);
   }
 
   saveZip() {