Add client-side PDF conversion tools

src/tools/pdf-to-docx-ocr/run.ts

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+import type { ToolInput } from "../../core/io/input-types";
+import type { ToolResult } from "../../core/io/output-types";
+import type { ToolContext } from "../../core/plugins/plugin-types";
+import type { PdfToDocxOcrOptions } from "./index";
+
+function abortIfNeeded(signal: AbortSignal) {
+  if (signal.aborted) throw new DOMException("Operation cancelled", "AbortError");
+}
+
+export async function runPdfToDocxOcr(
+  input: ToolInput,
+  options: PdfToDocxOcrOptions,
+  context: ToolContext
+): Promise<ToolResult> {
+  const file = input.files?.[0];
+  if (!file) throw new Error("Add a PDF document.");
+  if (file.type && file.type !== "application/pdf") throw new Error("The selected file is not a PDF.");
+
+  abortIfNeeded(context.signal);
+  context.reportProgress({ percentage: 1, message: "Opening PDF locally..." });
+
+  const [pdfjs, { createWorker }] = await Promise.all([
+    import("pdfjs-dist"),
+    import("tesseract.js"),
+  ]);
+  pdfjs.GlobalWorkerOptions.workerSrc = new URL(
+    "pdfjs-dist/build/pdf.worker.min.mjs",
+    import.meta.url
+  ).toString();
+
+  const loadingTask = pdfjs.getDocument({ data: new Uint8Array(await file.arrayBuffer()) });
+  const pdf = await loadingTask.promise;
+  const pageTexts: string[] = [];
+  const scale = options.quality === "high" ? 2.5 : 1.75;
+
+  const worker = await createWorker(options.language, undefined, {
+    logger: (message) => {
+      if (message.status === "recognizing text" && typeof message.progress === "number") {
+        const completedPages = pageTexts.length;
+        context.reportProgress({
+          percentage: 8 + ((completedPages + message.progress) / pdf.numPages) * 88,
+          message: `Recognizing page ${completedPages + 1} of ${pdf.numPages}...`,
+        });
+      }
+    },
+  });
+
+  const cancelWorker = () => void worker.terminate();
+  context.signal.addEventListener("abort", cancelWorker, { once: true });
+
+  try {
+    for (let pageNumber = 1; pageNumber <= pdf.numPages; pageNumber += 1) {
+      abortIfNeeded(context.signal);
+      context.reportProgress({
+        percentage: 5 + ((pageNumber - 1) / pdf.numPages) * 88,
+        message: `Rendering page ${pageNumber} of ${pdf.numPages} locally...`,
+      });
+
+      const page = await pdf.getPage(pageNumber);
+      const viewport = page.getViewport({ scale });
+      const canvas = document.createElement("canvas");
+      canvas.width = Math.ceil(viewport.width);
+      canvas.height = Math.ceil(viewport.height);
+      const canvasContext = canvas.getContext("2d", { alpha: false });
+      if (!canvasContext) throw new Error("Your browser could not render this PDF page.");
+      await page.render({ canvas, canvasContext, viewport }).promise;
+      abortIfNeeded(context.signal);
+
+      const result = await worker.recognize(canvas);
+      pageTexts.push(result.data.text.trim());
+      page.cleanup();
+      canvas.width = 1;
+      canvas.height = 1;
+    }
+  } finally {
+    context.signal.removeEventListener("abort", cancelWorker);
+    await worker.terminate().catch(() => undefined);
+    await loadingTask.destroy();
+  }
+
+  abortIfNeeded(context.signal);
+  context.reportProgress({ percentage: 97, message: "Building editable DOCX..." });
+  const { Document, Packer, Paragraph } = await import("docx");
+  const children: Array<InstanceType<typeof Paragraph>> = [];
+  pageTexts.forEach((text, pageIndex) => {
+    const lines = text.split(/\r?\n/);
+    lines.forEach((line, lineIndex) => {
+      children.push(new Paragraph({
+        text: line,
+        pageBreakBefore: options.pageBreaks && pageIndex > 0 && lineIndex === 0,
+        spacing: { after: line.trim() ? 120 : 0 },
+      }));
+    });
+  });
+
+  const docxDocument = new Document({ sections: [{ children }] });
+  const blob = await Packer.toBlob(docxDocument);
+  context.reportProgress({ percentage: 100, message: "DOCX ready." });
+
+  return {
+    type: "files",
+    files: [{
+      name: `${file.name.replace(/\.pdf$/i, "")}_ocr.docx`,
+      mimeType: "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+      blob,
+      sizeBefore: file.size,
+      sizeAfter: blob.size,
+    }],
+  };
+}