Generate outfit images by ID alone

Not using this anywhere in-app yet! But might swap it into the user outfits page, and use it to server-side-render social sharing meta tags!

Also eyeing this as a way to replace our nearly 1TB of outfit image S3 storage, and save $20/mo…

api/outfitImage.js

@@ -1,3 +1,26 @@
+/**
+ * /api/outfitImage returns an image of an outfit!
+ *
+ * Parameters:
+ *   - size: Must be 150 or 300, to indicate the image size you'd like back.
+ *   - layerUrls: A comma-separated list of URLs to render, in order from
+ *                bottom to top. This is a sorta "independent" render mode,
+ *                not bound to any saved outfit. The URLs must match a known
+ *                layer URL format.
+ *   - id: Instead of `layerUrls`, you can instead provide an outfit ID, which
+ *         will load the outfit data and render it directly.
+ *   - updatedAt: If you provide an `id`, you must also provide `updatedAt`:
+ *                the UNIX timestamp for when the outfit was last updated. This
+ *                has no effect on output, but is very important for caching:
+ *                we always return a long-term cache header, so our CDN cache
+ *                will likely cache the requested URL forever. That way, outfit
+ *                images will cache long-term, unless they're updated and the
+ *                user requests a new URL. (This _does_ mean this API can no
+ *                longer be used for simple embeds in e.g. petpages that
+ *                auto-update to the latest version of the image… but I don't
+ *                actually know if anyone does that? If we need a
+ *                latest-version API, we can build that as a separate case.)
+ */
 const beeline = require("honeycomb-beeline")({
   writeKey: process.env["HONEYCOMB_WRITE_KEY"],
   dataset:
@@ -7,7 +30,15 @@ const beeline = require("honeycomb-beeline")({
   serviceName: "impress-2020-gql-server",
 });
 
-const { renderOutfitImage } = require("../src/server/outfit-images");
+import fetch from "node-fetch";
+import gql from "graphql-tag";
+import { print as graphqlPrint } from "graphql/language/printer";
+
+import { renderOutfitImage } from "../src/server/outfit-images";
+import getVisibleLayers, {
+  petAppearanceFragmentForGetVisibleLayers,
+  itemAppearanceFragmentForGetVisibleLayers,
+} from "../src/shared/getVisibleLayers";
 
 const VALID_LAYER_URLS = [
   /^https:\/\/(impress-asset-images\.openneo\.net|impress-asset-images\.s3\.amazonaws\.com)\/(biology|object)\/[0-9]{3}\/[0-9]{3}\/[0-9]{3}\/[0-9]+\/(150|300)x(150|300)\.png(\?[a-zA-Z0-9_-]+)?$/,
@@ -15,21 +46,40 @@ const VALID_LAYER_URLS = [
 ];
 
 async function handle(req, res) {
-  if (!req.query.layerUrls) {
-    res.setHeader("Content-Type", "text/plain");
-    return res.status(400).send(`Missing required parameter: layerUrls`);
-  }
-  const layerUrls = req.query.layerUrls.split(",");
-
   const size = parseInt(req.query.size);
   if (size !== 150 && size !== 300) {
-    res.setHeader("Content-Type", "text/plain");
+    return reject(res, `Size must be 150 or 300`);
-    return res.status(400).send(`Size must be 150 or 300`);
+  }
+
+  let layerUrls;
+  if (req.query.layerUrls) {
+    layerUrls = req.query.layerUrls.split(",");
+  } else if (req.query.id) {
+    if (!req.query.updatedAt) {
+      return reject(
+        res,
+        `updatedAt parameter is required, when id parameter is provided`
+      );
+    }
+
+    const outfitId = req.query.id;
+    try {
+      layerUrls = await loadLayerUrlsForSavedOutfit(outfitId, size);
+    } catch (e) {
+      console.error(e);
+      return reject(
+        res,
+        `Error loading data for outfit ${outfitId}: ${e.message}`,
+        500
+      );
+    }
+  } else {
+    return reject(res, `Missing required parameter: layerUrls`);
   }
 
   for (const layerUrl of layerUrls) {
     if (!VALID_LAYER_URLS.some((pattern) => layerUrl.match(pattern))) {
-      return res.status(400).send(`Unexpected layer URL format: ${layerUrl}`);
+      return reject(res, `Unexpected layer URL format: ${layerUrl}`);
     }
   }
 
@@ -38,8 +88,7 @@ async function handle(req, res) {
     imageResult = await renderOutfitImage(layerUrls, size);
   } catch (e) {
     console.error(e);
-    res.setHeader("Content-Type", "text/plain");
+    return reject(res, `Error rendering image: ${e.message}`);
-    return res.status(400).send(`Error rendering image: ${e.message}`);
   }
 
   const { image, status } = imageResult;
@@ -49,6 +98,8 @@ async function handle(req, res) {
     // layers are ~immutable too, and that our rendering algorithm will almost
     // never change in a way that requires pushing changes. If it does, we
     // should add a cache-buster to the URL!
+    //
+    // TODO: Maybe verify that there's a timestamp param in the ?id case?
     res.setHeader("Cache-Control", "public, max-age=604800, immutable");
     res.status(200);
   } else {
@@ -66,6 +117,66 @@ async function handle(req, res) {
   return res.send(image);
 }
 
+const GRAPHQL_ENDPOINT =
+  process.env.NODE_ENV === "development"
+    ? "http://localhost:3000/api/graphql"
+    : "https://impress-2020.openneo.net/api/graphql";
+
+// NOTE: Unlike in-app views, we only load PNGs here. We expect this to
+//       generally perform better, and be pretty reliable now that TNT is
+//       generating canonical PNGs for every layer!
+const GRAPHQL_QUERY = gql`
+  query ApiOutfitImage($outfitId: ID!, $size: LayerImageSize) {
+    outfit(id: $outfitId) {
+      petAppearance {
+        layers {
+          imageUrl(size: $size)
+        }
+        ...PetAppearanceForGetVisibleLayers
+      }
+      itemAppearances {
+        layers {
+          imageUrl(size: $size)
+        }
+        ...ItemAppearanceForGetVisibleLayers
+      }
+    }
+  }
+  ${petAppearanceFragmentForGetVisibleLayers}
+  ${itemAppearanceFragmentForGetVisibleLayers}
+`;
+const GRAPHQL_QUERY_STRING = graphqlPrint(GRAPHQL_QUERY);
+
+async function loadLayerUrlsForSavedOutfit(outfitId, size) {
+  const { errors, data } = await fetch(GRAPHQL_ENDPOINT, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+    },
+    body: JSON.stringify({
+      query: GRAPHQL_QUERY_STRING,
+      variables: { outfitId, size: `SIZE_${size}` },
+    }),
+  }).then((res) => res.json());
+
+  if (errors && errors.length > 0) {
+    throw new Error(
+      `GraphQL Error: ${errors.map((e) => e.message).join(", ")}`
+    );
+  }
+
+  const { petAppearance, itemAppearances } = data.outfit;
+  const visibleLayers = getVisibleLayers(petAppearance, itemAppearances);
+  return visibleLayers
+    .sort((a, b) => a.depth - b.depth)
+    .map((layer) => layer.imageUrl);
+}
+
+function reject(res, message, status = 400) {
+  res.setHeader("Content-Type", "text/plain");
+  return res.status(status).send(message);
+}
+
 async function handleWithBeeline(req, res) {
   beeline.withTrace(
     { name: "api/outfitImage", operation_name: "api/outfitImage" },

src/shared/getVisibleLayers.js

@@ -92,6 +92,8 @@ function getVisibleLayers(petAppearance, itemAppearances) {
   return visibleLayers;
 }
 
+// TODO: The web client could save bandwidth by applying @client to the `depth`
+//       field, because it already has zone depths cached.
 export const itemAppearanceFragmentForGetVisibleLayers = gql`
   fragment ItemAppearanceForGetVisibleLayers on ItemAppearance {
     id
@@ -99,7 +101,7 @@ export const itemAppearanceFragmentForGetVisibleLayers = gql`
       id
       zone {
         id
-        depth @client
+        depth
       }
     }
     restrictedZones {
@@ -108,6 +110,8 @@ export const itemAppearanceFragmentForGetVisibleLayers = gql`
   }
 `;
 
+// TODO: The web client could save bandwidth by applying @client to the `depth`
+//       field, because it already has zone depths cached.
 export const petAppearanceFragmentForGetVisibleLayers = gql`
   fragment PetAppearanceForGetVisibleLayers on PetAppearance {
     id
@@ -116,7 +120,7 @@ export const petAppearanceFragmentForGetVisibleLayers = gql`
       id
       zone {
         id
-        depth @client
+        depth
       }
     }
     restrictedZones {