sync & async api

routes/api/workflow.js

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+import express from 'express';
+import multer from 'multer';
+import crypto from 'crypto';
+import stream from "stream";
+
+import { traverseOperations } from "../../traverseOperations.js";
+
+const activeWorkflows = {};
+
+const router = express.Router();
+
+router.post("/", [
+    multer().array("files"),
+    async (req, res, next) => {
+        const workflow = JSON.parse(req.body.workflow);
+        console.log("fileCount: ", req.files.length);
+        console.log("workflow: ", workflow);
+
+        // TODO: Validate
+
+        let workflowID = undefined;
+
+        const inputs = await Promise.all(req.files.map(async file => {
+            console.log(file);
+            return {
+                originalFileName: file.originalname.replace(/\.[^/.]+$/, ""),
+                fileName: file.originalname.replace(/\.[^/.]+$/, ""),
+                buffer: new Uint8Array(await file.buffer)
+            }
+        }));
+
+        // Allow option to do it synchronously and just make a long request
+        if(req.body.async === "false") {
+            console.log("Don't do async");
+
+            const pdfResults = await traverseOperations(workflow.operations, inputs);
+            downloadHandler(res, pdfResults);
+        }
+        else {
+            workflowID = generateWorkflowID();
+            activeWorkflows[workflowID] = {
+                createdAt: Date.now(),
+                finished: false, 
+                eventStream: null,
+                result: null,
+                // TODO: When auth is implemented: owner
+            }
+
+            res.status(501).json({
+                "warning": "Unfinished Endpoint",
+                "workflowID": workflowID,
+                "data-recieved": {
+                    "fileCount": req.files.length,
+                    "workflow": workflow
+                }
+            });
+
+            traverseOperations(workflow.operations, inputs).then((pdfResults) => {
+                activeWorkflows[workflowID].result = pdfResults;
+                activeWorkflows[workflowID].finished = true;
+                // TODO: Post to eventStream
+            });
+        }
+    }
+]);
+
+router.get("/progress/:workflowUuid", (req, res, nex) => {
+    // TODO: Validation
+
+    // Return current progress
+    const workflow = activeWorkflows[req.params.workflowUuid];
+    res.status(200).json({ createdAt: workflow.createdAt, finished: workflow.finished });
+});
+
+router.get("/progress-stream/:workflowUuid", (req, res, nex) => {
+    // TODO: Send realtime updates
+    res.status(501).json({"warning": "Event-Stream has not been implemented yet."});
+});
+
+router.get("/result/:workflowUuid", (req, res, nex) => {
+    // TODO: Validation
+
+    /* 
+     * If workflow isn't done return error
+     * Send file, TODO: if there are multiple outputs return as zip
+     * If download is done, delete results / allow deletion within the next 5-60 mins
+    */
+    const workflow = activeWorkflows[req.params.workflowUuid];
+    if(!workflow.finished) {
+        res.status(202).json({ message: "Workflow hasn't finished yet. Check progress or connect to progress-steam to get notified when its done." });
+        return
+    }
+
+    downloadHandler(res, workflow.result);
+    // Delete workflow / results when done.
+    delete activeWorkflows[req.params.workflowUuid];
+});
+
+router.post("/abort/:workflowUuid", (req, res, nex) => {
+    // TODO: Abort workflow
+    res.status(501).json({"warning": "Abortion has not been implemented yet."});
+});
+
+function generateWorkflowID() {
+    return crypto.randomUUID();
+}
+
+function downloadHandler(res, pdfResults) {
+    if(pdfResults.length > 1) {
+        res.status(501).json({"warning": "The workflow had multiple outputs, this is not implemented yet."});
+        // TODO: Implement ZIP
+    }
+    else {
+        const readStream = new stream.PassThrough();
+        readStream.end(pdfResults[0].buffer);
+
+        // TODO: Implement other file types (mostly fro image & text extraction)
+        res.set("Content-disposition", 'attachment; filename=' + pdfResults[0].fileName + ".pdf");
+        res.set("Content-Type", "application/pdf");
+
+        readStream.pipe(res);
+    }
+}
+
+export default router;