feat: extract reusable @mintel/payload-ai package

packages/payload-ai/src/endpoints/replicateMediaEndpoint.ts

@@ -0,0 +1,177 @@
+import type { PayloadRequest, PayloadHandler } from "payload";
+import Replicate from "replicate";
+
+type Action = "upscale" | "recover";
+
+const replicate = new Replicate({
+    auth: process.env.REPLICATE_API_KEY,
+});
+
+/**
+ * Downloads a remote URL and returns a Buffer.
+ */
+async function downloadImage(url: string): Promise<Buffer> {
+    const res = await fetch(url);
+    if (!res.ok) throw new Error(`Failed to download image: ${res.status} ${res.statusText}`);
+    const arrayBuffer = await res.arrayBuffer();
+    return Buffer.from(arrayBuffer);
+}
+
+/**
+ * Resolves the public URL for a media document.
+ * Handles both S3 and local static files.
+ */
+function resolveMediaUrl(doc: any): string | null {
+    // S3 storage sets `url` directly
+    if (doc.url) return doc.url;
+
+    // Local static files: build from NEXT_PUBLIC_BASE_URL + /media/<filename>
+    const base = process.env.NEXT_PUBLIC_BASE_URL || "http://localhost:3000";
+    if (doc.filename) return `${base}/media/${doc.filename}`;
+
+    return null;
+}
+
+export const replicateMediaHandler: PayloadHandler = async (
+    req: PayloadRequest,
+) => {
+    const { id } = req.routeParams as { id: string };
+    const payload = req.payload;
+
+    // Parse action from request body
+    let action: Action;
+    try {
+        const body = await req.json?.();
+        action = body?.action as Action;
+    } catch {
+        return Response.json({ error: "Invalid request body" }, { status: 400 });
+    }
+
+    if (action !== "upscale" && action !== "recover") {
+        return Response.json(
+            { error: "Invalid action. Must be 'upscale' or 'recover'." },
+            { status: 400 },
+        );
+    }
+
+    // Fetch the media document
+    let mediaDoc: any;
+    try {
+        mediaDoc = await payload.findByID({ collection: "media", id });
+    } catch {
+        return Response.json({ error: "Media not found" }, { status: 404 });
+    }
+
+    if (!mediaDoc) {
+        return Response.json({ error: "Media not found" }, { status: 404 });
+    }
+
+    // Check that it's an image
+    const mimeType: string = mediaDoc.mimeType || "";
+    if (!mimeType.startsWith("image/")) {
+        return Response.json(
+            { error: "This media file is not an image and cannot be AI-processed." },
+            { status: 422 },
+        );
+    }
+
+    const imageUrl = resolveMediaUrl(mediaDoc);
+    if (!imageUrl) {
+        return Response.json(
+            { error: "Could not resolve a public URL for this media file." },
+            { status: 422 },
+        );
+    }
+
+    // --- Run Replicate ---
+    let outputUrl: string;
+
+    try {
+        if (action === "upscale") {
+            console.log(`[AI Media] Starting upscale for media ${id} – ${imageUrl}`);
+            const output = await replicate.run("google/upscaler", {
+                input: {
+                    image: imageUrl,
+                },
+            });
+            // google/upscaler returns a string URL
+            outputUrl = typeof output === "string" ? output : (output as any)?.url ?? String(output);
+        } else {
+            // recover
+            console.log(`[AI Media] Starting photo recovery for media ${id} – ${imageUrl}`);
+            const output = await replicate.run(
+                "microsoft/bringing-old-photos-back-to-life",
+                {
+                    input: {
+                        image: imageUrl,
+                        HR: true,
+                    },
+                },
+            );
+            // returns a FileOutput or URL string
+            outputUrl = typeof output === "string" ? output : (output as any)?.url ?? String(output);
+        }
+    } catch (err: any) {
+        console.error("[AI Media] Replicate error:", err);
+        return Response.json(
+            { error: err?.message ?? "Replicate API call failed" },
+            { status: 500 },
+        );
+    }
+
+    // --- Download and re-upload as new media document ---
+    let imageBuffer: Buffer;
+    try {
+        imageBuffer = await downloadImage(outputUrl);
+    } catch (err: any) {
+        console.error("[AI Media] Download error:", err);
+        return Response.json(
+            { error: `Failed to download result: ${err?.message}` },
+            { status: 500 },
+        );
+    }
+
+    const suffix = action === "upscale" ? "_upscaled" : "_recovered";
+    const originalName: string = mediaDoc.filename || "image.jpg";
+    const ext = originalName.includes(".") ? `.${originalName.split(".").pop()}` : ".jpg";
+    const baseName = originalName.includes(".")
+        ? originalName.slice(0, originalName.lastIndexOf("."))
+        : originalName;
+    const newFilename = `${baseName}${suffix}${ext}`;
+    const originalAlt: string = mediaDoc.alt || originalName;
+
+    let newMedia: any;
+    try {
+        newMedia = await payload.create({
+            collection: "media",
+            data: {
+                alt: `${originalAlt}${suffix}`,
+            },
+            file: {
+                data: imageBuffer,
+                mimetype: mimeType,
+                name: newFilename,
+                size: imageBuffer.byteLength,
+            },
+        });
+    } catch (err: any) {
+        console.error("[AI Media] Upload error:", err);
+        return Response.json(
+            { error: `Failed to save result: ${err?.message}` },
+            { status: 500 },
+        );
+    }
+
+    console.log(
+        `[AI Media] ${action} complete – new media ID: ${newMedia.id}`,
+    );
+
+    return Response.json(
+        {
+            message: `AI ${action} successful. New media document created.`,
+            mediaId: newMedia.id,
+            url: resolveMediaUrl(newMedia),
+        },
+        { status: 200 },
+    );
+};