1 files changed, 197 insertions, 0 deletions
diff --git a/apps/workers/assetPreprocessingWorker.ts b/apps/workers/assetPreprocessingWorker.ts
new file mode 100644
index 00000000..5c4937e5
--- /dev/null
+++ b/apps/workers/assetPreprocessingWorker.ts
@@ -0,0 +1,197 @@
+import os from "os";
+import { eq } from "drizzle-orm";
+import { DequeuedJob, Runner } from "liteque";
+import PDFParser from "pdf2json";
+import { createWorker } from "tesseract.js";
+
+import type { AssetPreprocessingRequest } from "@hoarder/shared/queues";
+import { db } from "@hoarder/db";
+import { bookmarkAssets, bookmarks } from "@hoarder/db/schema";
+import { readAsset } from "@hoarder/shared/assetdb";
+import serverConfig from "@hoarder/shared/config";
+import logger from "@hoarder/shared/logger";
+import {
+  AssetPreprocessingQueue,
+  OpenAIQueue,
+  triggerSearchReindex,
+} from "@hoarder/shared/queues";
+
+export class AssetPreprocessingWorker {
+  static build() {
+    logger.info("Starting asset preprocessing worker ...");
+    const worker = new Runner<AssetPreprocessingRequest>(
+      AssetPreprocessingQueue,
+      {
+        run: run,
+        onComplete: async (job) => {
+          const jobId = job.id;
+          logger.info(`[assetPreprocessing][${jobId}] Completed successfully`);
+          return Promise.resolve();
+        },
+        onError: async (job) => {
+          const jobId = job.id;
+          logger.error(
+            `[assetPreprocessing][${jobId}] Asset preprocessing failed: ${job.error}\n${job.error.stack}`,
+          );
+          return Promise.resolve();
+        },
+      },
+      {
+        concurrency: 1,
+        pollIntervalMs: 1000,
+        timeoutSecs: 30,
+      },
+    );
+
+    return worker;
+  }
+}
+
+async function readImageText(buffer: Buffer) {
+  if (serverConfig.ocr.langs.length == 1 && serverConfig.ocr.langs[0] == "") {
+    return null;
+  }
+  const worker = await createWorker(serverConfig.ocr.langs, undefined, {
+    cachePath: serverConfig.ocr.cacheDir ?? os.tmpdir(),
+  });
+  try {
+    const ret = await worker.recognize(buffer);
+    if (ret.data.confidence <= serverConfig.ocr.confidenceThreshold) {
+      return null;
+    }
+    return ret.data.text;
+  } finally {
+    await worker.terminate();
+  }
+}
+
+async function readPDFText(buffer: Buffer): Promise<{
+  text: string;
+  metadata: Record<string, string>;
+}> {
+  return new Promise((resolve, reject) => {
+    // Need raw text flag represents as number (1), reference : https://github.com/modesty/pdf2json/issues/76#issuecomment-236569265
+    const pdfParser = new PDFParser(null, 1);
+    pdfParser.on("pdfParser_dataError", reject);
+    pdfParser.on("pdfParser_dataReady", (pdfData) => {
+      resolve({
+        // The type isn't set correctly, reference : https://github.com/modesty/pdf2json/issues/327
+        // eslint-disable-next-line
+        text: (pdfParser as any).getRawTextContent(),
+        metadata: pdfData.Meta,
+      });
+    });
+    pdfParser.parseBuffer(buffer);
+  });
+}
+
+async function preprocessImage(
+  jobId: string,
+  asset: Buffer,
+): Promise<{ content: string; metadata: string | null } | undefined> {
+  let imageText = null;
+  try {
+    imageText = await readImageText(asset);
+  } catch (e) {
+    logger.error(
+      `[assetPreprocessing][${jobId}] Failed to read image text: ${e}`,
+    );
+  }
+  if (!imageText) {
+    return undefined;
+  }
+
+  logger.info(
+    `[assetPreprocessing][${jobId}] Extracted ${imageText.length} characters from image.`,
+  );
+  return { content: imageText, metadata: null };
+}
+
+async function preProcessPDF(
+  jobId: string,
+  asset: Buffer,
+): Promise<{ content: string; metadata: string | null } | undefined> {
+  const pdfParse = await readPDFText(asset);
+  if (!pdfParse?.text) {
+    throw new Error(
+      `[assetPreprocessing][${jobId}] PDF text is empty. Please make sure that the PDF includes text and not just images.`,
+    );
+  }
+  logger.info(
+    `[assetPreprocessing][${jobId}] Extracted ${pdfParse.text.length} characters from pdf.`,
+  );
+  return {
+    content: pdfParse.text,
+    metadata: pdfParse.metadata ? JSON.stringify(pdfParse.metadata) : null,
+  };
+}
+
+async function run(req: DequeuedJob<AssetPreprocessingRequest>) {
+  const jobId = req.id;
+  const bookmarkId = req.data.bookmarkId;
+
+  const bookmark = await db.query.bookmarks.findFirst({
+    where: eq(bookmarks.id, bookmarkId),
+    with: {
+      asset: true,
+    },
+  });
+
+  logger.info(
+    `[assetPreprocessing][${jobId}] Starting an asset preprocessing job for bookmark with id "${bookmarkId}"`,
+  );
+
+  if (!bookmark) {
+    throw new Error(`[assetPreprocessing][${jobId}] Bookmark not found`);
+  }
+
+  if (!bookmark.asset) {
+    throw new Error(
+      `[assetPreprocessing][${jobId}] Bookmark is not an asset (not an image or pdf)`,
+    );
+  }
+
+  const { asset } = await readAsset({
+    userId: bookmark.userId,
+    assetId: bookmark.asset.assetId,
+  });
+
+  if (!asset) {
+    throw new Error(
+      `[assetPreprocessing][${jobId}] AssetId ${bookmark.asset.assetId} for bookmark ${bookmarkId} not found`,
+    );
+  }
+
+  let result: { content: string; metadata: string | null } | undefined =
+    undefined;
+
+  switch (bookmark.asset.assetType) {
+    case "image":
+      result = await preprocessImage(jobId, asset);
+      break;
+    case "pdf":
+      result = await preProcessPDF(jobId, asset);
+      break;
+    default:
+      throw new Error(
+        `[assetPreprocessing][${jobId}] Unsupported bookmark type`,
+      );
+  }
+
+  if (result) {
+    await db
+      .update(bookmarkAssets)
+      .set({
+        content: result.content,
+        metadata: result.metadata,
+      })
+      .where(eq(bookmarkAssets.id, bookmarkId));
+  }
+
+  await OpenAIQueue.enqueue({
+    bookmarkId,
+  });
+
+  // Update the search index
+  await triggerSearchReindex(bookmarkId);
+}