fix: auto-regenerate CAM artifacts when PDF/DOCX missing

backend/src/routes/cam.js

@@ -12,11 +12,14 @@ router.get("/:jobId/download/:format", async (c) => {
   if (!["pdf", "docx"].includes(format)) {
     return c.json({ error: "Valid formats: pdf, docx" }, 400);
   }
-  try {
-    const resp = await axios.get(
-      `${config.aiServiceUrl}/api/v1/cam/download/${jobId}/${format}`,
-      { responseType: "arraybuffer", timeout: 30000 },
-    );
+
+  const aiDownloadUrl = `${config.aiServiceUrl}/api/v1/cam/download/${jobId}/${format}`;
+
+  async function proxyDownloadOnce() {
+    const resp = await axios.get(aiDownloadUrl, {
+      responseType: "arraybuffer",
+      timeout: 30000,
+    });
     const ct =
       format === "pdf"
         ? "application/pdf"
@@ -28,13 +31,47 @@ router.get("/:jobId/download/:format", async (c) => {
       `${disposition}; filename="${jobId}_Credit_Memo.${format}"`,
     );
     return c.body(resp.data);
+  }
+
+  async function waitForCamArtifacts() {
+    // Trigger regenerate, then poll CAM result until not processing.
+    await axios.post(
+      `${config.aiServiceUrl}/api/v1/cam/regenerate`,
+      { job_id: jobId },
+      { timeout: 120000 },
+    );
+
+    for (let i = 0; i < 40; i++) {
+      const pollRes = await axios.get(
+        `${config.aiServiceUrl}/api/v1/cam/result/${jobId}`,
+        { timeout: 30000 },
+      );
+      if (pollRes.data?.status !== "processing") return;
+      await new Promise((r) => setTimeout(r, 2000));
+    }
+
+    throw new Error("CAM regeneration timed out");
+  }
+
+  try {
+    return await proxyDownloadOnce();
   } catch (err) {
     const status = err.response?.status || 500;
-    const msg =
-      status === 404
-        ? `${format.toUpperCase()} not yet available`
-        : "Download failed";
-    return c.json({ error: msg }, status);
+    // Auto-heal missing artifacts for completed jobs: regenerate CAM and retry once.
+    if (status === 404) {
+      try {
+        await waitForCamArtifacts();
+        return await proxyDownloadOnce();
+      } catch (regenErr) {
+        const msg =
+          regenErr?.message === "CAM regeneration timed out"
+            ? "PDF regeneration timed out. Please retry in a minute."
+            : `${format.toUpperCase()} not yet available`;
+        return c.json({ error: msg }, 504);
+      }
+    }
+
+    return c.json({ error: "Download failed" }, status);
   }
 });