outfit-images: render actual PNG and SVG layers!

api/outfitImage.js

@@ -9,9 +9,62 @@ const beeline = require("honeycomb-beeline")({
 
 const { renderOutfitImage } = require("../src/server/outfit-images");
 
+const VALID_LAYER_URLS = [
+  /^https:\/\/impress-asset-images\.s3\.amazonaws\.com\/(biology|object)\/[0-9]{3}\/[0-9]{3}\/[0-9]{3}\/[0-9]+\/150x150\.png$/,
+  /^http:\/\/images\.neopets\.com\/cp\/(biology|object)\/data\/[0-9]{3}\/[0-9]{3}\/[0-9]{3}\/[a-zA-Z0-9_]+\/[a-zA-Z0-9_]+\.svg$/,
+];
+
 async function handle(req, res) {
-  const image = await renderOutfitImage();
-  return res.status(200).setHeader("Content-Type", "image/png").send(image);
+  if (!req.query.layerUrls) {
+    return res
+      .status(400)
+      .setHeader("Content-Type", "text/plain")
+      .send(`Missing required parameter: layerUrls`);
+  }
+
+  const layerUrls = req.query.layerUrls.split(",");
+
+  for (const layerUrl of layerUrls) {
+    if (!VALID_LAYER_URLS.some((pattern) => layerUrl.match(pattern))) {
+      return res
+        .status(400)
+        .setHeader("Content-Type", "text/plain")
+        .send(`Unexpected layer URL format: ${layerUrl}`);
+    }
+  }
+
+  let imageResult;
+  try {
+    imageResult = await renderOutfitImage(layerUrls, 150);
+  } catch (e) {
+    console.error(e);
+    return res
+      .status(400)
+      .setHeader("Content-Type", "text/plain")
+      .send(`Error rendering image: ${e.message}`);
+  }
+
+  const { image, status } = imageResult;
+
+  if (status === "success") {
+    // On success, we use very aggressive caching, on the assumption that
+    // 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!
+    res
+      .status(200)
+      .setHeader("Cache-Control", "public, max-age=604800, immutable");
+  } else {
+    // On partial failure, we still send the image, but with a 500 status. We
+    // send a long-lived cache header, but in such a way that the user can
+    // refresh the page to try again. (`private` means the CDN won't cache it,
+    // and we don't send `immutable`, which would save it even across reloads.)
+    // The 500 won't really affect the client, which will still show the image
+    // without feedback to the user - but it's a helpful debugging hint.
+    res.status(500).setHeader("Cache-Control", "private, max-age=604800");
+  }
+
+  return res.setHeader("Content-Type", "image/png").send(image);
 }
 
 export default async (req, res) => {

src/server/outfit-images.js

@@ -1,17 +1,30 @@
-const path = require("path");
-
 const { createCanvas, loadImage } = require("canvas");
 
-async function renderOutfitImage(layerRefs) {
-  const canvas = createCanvas(90, 90);
+async function renderOutfitImage(layerRefs, size) {
+  const canvas = createCanvas(size, size);
   const ctx = canvas.getContext("2d");
 
-  const image = await loadImage(
-    path.join(__dirname, "../app/images/feedback-xwee.png")
-  );
-  ctx.drawImage(image, 0, 0, 90, 90);
+  const images = await Promise.all(layerRefs.map(loadImageAndSkipOnFailure));
+  const loadedImages = images.filter((image) => image);
+  for (const image of loadedImages) {
+    ctx.drawImage(image, 0, 0, size, size);
+  }
 
-  return canvas.toBuffer();
+  return {
+    image: canvas.toBuffer(),
+    status:
+      loadedImages.length === layerRefs.length ? "success" : "partial-failure",
+  };
+}
+
+async function loadImageAndSkipOnFailure(url) {
+  try {
+    const image = await loadImage(url);
+    return image;
+  } catch (e) {
+    console.warn(`Error loading layer, skipping: ${e.message}. (${url})`);
+    return null;
+  }
 }
 
 module.exports = { renderOutfitImage };

src/server/outfit-images.test.js

@@ -3,9 +3,52 @@ const { renderOutfitImage } = require("./outfit-images");
 const { toMatchImageSnapshot } = require("jest-image-snapshot");
 expect.extend({ toMatchImageSnapshot });
 
+const originalConsoleWarn = console.warn;
+
 describe("renderOutfitImage", () => {
-  it("renders a test xwee", async () => {
-    const image = await renderOutfitImage();
+  beforeEach(() => {
+    console.warn = jest.fn();
+  });
+
+  afterEach(() => {
+    console.warn = originalConsoleWarn;
+  });
+
+  it("renders the Moon and Stars Background and Green Leaf String Lights, as PNG", async () => {
+    const image = await renderOutfitImage(
+      [
+        "https://impress-asset-images.s3.amazonaws.com/object/000/000/006/6829/600x600.png",
+        "https://impress-asset-images.s3.amazonaws.com/object/000/000/036/36414/600x600.png",
+      ],
+      600
+    );
     expect(image).toMatchImageSnapshot();
+    expect(console.warn).not.toHaveBeenCalled();
+  });
+
+  it("renders the Moon and Stars Background and Green Leaf String Lights, as SVG", async () => {
+    const image = await renderOutfitImage(
+      [
+        "http://images.neopets.com/cp/items/data/000/000/006/6829_1707e50385/6829.svg",
+        "http://images.neopets.com/cp/items/data/000/000/036/36414_1e2aaab4ad/36414.svg",
+      ],
+      600
+    );
+    expect(image).toMatchImageSnapshot();
+    expect(console.warn).not.toHaveBeenCalled();
+  });
+
+  it("skips network failures, and logs an error", async () => {
+    const image = await renderOutfitImage(
+      [
+        "https://impress-asset-images.s3.amazonaws.com/object/000/000/006/6829/600x600.png",
+        "https://impress-asset-images.s3.amazonaws.com/object/000/000/000/00000000/600x600.png", // fake URL
+      ],
+      600
+    );
+    expect(image).toMatchImageSnapshot();
+    expect(console.warn).toHaveBeenCalledWith(
+      `Error loading layer, skipping: Server responded with 403. (https://impress-asset-images.s3.amazonaws.com/object/000/000/000/00000000/600x600.png)`
+    );
   });
 });