From 152daf60fbddd40122dbe3800d3c036d028d450c Mon Sep 17 00:00:00 2001
From: Felix Kaspar <ich@felixkaspar.com>
Date: Wed, 21 Aug 2024 21:11:07 +0200
Subject: [PATCH] SingleLargePage Feature

---
 .../public/locales/singleLargePage/en.json    |  4 ++
 .../src/functions/singleLargePage.schema.ts   | 18 ++++++
 .../src/functions/singleLargePage.ts          | 56 +++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 shared-operations/public/locales/singleLargePage/en.json
 create mode 100644 shared-operations/src/functions/singleLargePage.schema.ts
 create mode 100644 shared-operations/src/functions/singleLargePage.ts

diff --git a/shared-operations/public/locales/singleLargePage/en.json b/shared-operations/public/locales/singleLargePage/en.json
new file mode 100644
index 000000000..ee57487d6
--- /dev/null
+++ b/shared-operations/public/locales/singleLargePage/en.json
@@ -0,0 +1,4 @@
+{
+    "friendlyName": "Single Large Page",
+    "description": "Merge all pages of a document into a single long page."
+}
\ No newline at end of file
diff --git a/shared-operations/src/functions/singleLargePage.schema.ts b/shared-operations/src/functions/singleLargePage.schema.ts
new file mode 100644
index 000000000..eff813c9b
--- /dev/null
+++ b/shared-operations/src/functions/singleLargePage.schema.ts
@@ -0,0 +1,18 @@
+import { OperatorAvailability, OperatorSchema } from ".";
+import Joi from "@stirling-tools/joi";
+import { JoiPDFFileSchema } from "../wrappers/PdfFileJoi";
+
+import i18next from "i18next";
+
+export default new OperatorSchema({
+    joi: {
+        label: i18next.t("friendlyName", { ns: "singleLargePage" }),
+        description: i18next.t("description", { ns: "singleLargePage" }),
+        inputSchema: JoiPDFFileSchema.label(i18next.t("inputs.pdffile.name")).description(i18next.t("inputs.pdffile.description")),
+        valueSchema: Joi.object({}),
+        outputSchema: JoiPDFFileSchema.label(i18next.t("outputs.pdffile.name")).description(i18next.t("outputs.pdffile.description")),
+    },
+    materialSymbolName: "receipt",
+    availability: OperatorAvailability.Both
+}
+);
\ No newline at end of file
diff --git a/shared-operations/src/functions/singleLargePage.ts b/shared-operations/src/functions/singleLargePage.ts
new file mode 100644
index 000000000..c52b4b005
--- /dev/null
+++ b/shared-operations/src/functions/singleLargePage.ts
@@ -0,0 +1,56 @@
+
+import { PdfFile, RepresentationType } from "../wrappers/PdfFile";
+import { Operator, Progress, oneToOne } from ".";
+
+import { PDFDocument } from "pdf-lib";
+
+export class SingleLargePage extends Operator {
+    /** Merging pages from multiple pdfs into a singe output document. */
+    async run(input: PdfFile[], progressCallback: (state: Progress) => void): Promise<PdfFile[]> {
+        return oneToOne<PdfFile, PdfFile>(input, async (input) => {
+            const source = await input.pdfLibDocument;
+            const pages = source.getPages();
+            
+            const result = await PDFDocument.create(); 
+
+            // Calculate total height and maximum width
+            let totalHeight = 0;
+            let maxWidth = 0;
+            pages.forEach(page => {
+                const { width, height } = page.getSize();
+                totalHeight += height;
+                if (width > maxWidth) {
+                    maxWidth = width;
+                }
+            });
+ 
+            // Add a single large page to the new document
+            const largePage = result.addPage([maxWidth, totalHeight]);
+ 
+            const pageBytes = await source.save();
+            
+            // Draw each page from the original PDF onto the large page
+            let currentHeight = 0;
+            for (const page of pages) {
+                const { width, height } = page.getSize();
+ 
+                // Embed the original page into the new large page
+                const [embeddedPage] = await result.embedPdf(pageBytes, [pages.indexOf(page)]);
+ 
+                // Draw the embedded page onto the large page
+                largePage.drawPage(embeddedPage, {
+                    x: 0,
+                    y: totalHeight - currentHeight - height,
+                    width,
+                    height,
+                });
+ 
+                currentHeight += height;
+            }
+            
+            progressCallback({ curFileProgress: 0, operationProgress: 1 });
+
+            return new PdfFile("mergedPDF", result, RepresentationType.PDFLibDocument, "extended_" + input.filename);
+        });
+    }
+}
\ No newline at end of file