SA Model Viewer base

server.js

@@ -0,0 +1,126 @@
+require('dotenv').config();
+
+const express = require('express');
+const path = require('path');
+const fs = require('fs');
+
+const app = express();
+const PORT = process.env.PORT || 3000;
+
+// Where the model files actually live. Set S3_BUCKET to index a bucket;
+// otherwise the local models/ folder is used, which is what development does.
+const S3_BUCKET = process.env.S3_BUCKET || '';
+const S3_PREFIX = normalisePrefix(process.env.S3_PREFIX || 'skins/');
+const MODEL_ROOT = process.env.MODEL_ROOT || path.join(__dirname, 'models');
+
+// Where the browser fetches model files from. The default keeps them on this
+// origin under /models, which nginx can proxy to S3. Point it at a CDN origin
+// instead to have the browser fetch them directly.
+const MODELS_BASE_URL = (process.env.MODELS_BASE_URL || '/models').replace(/\/+$/, '');
+
+const INDEX_REFRESH_MS = Number(process.env.INDEX_REFRESH_MS || 15 * 60 * 1000);
+
+function normalisePrefix(prefix) {
+  const trimmed = prefix.replace(/^\/+|\/+$/g, '');
+  return trimmed ? trimmed + '/' : '';
+}
+
+// id -> { dff: true, txd: true }. Built once at boot and refreshed on a timer
+// so newly uploaded skins appear without a restart.
+let index = new Map();
+let indexError = null;
+
+function buildIndex(keys, prefix) {
+  const out = new Map();
+  for (const key of keys) {
+    if (!key.startsWith(prefix)) continue;
+    const name = key.slice(prefix.length);
+    const match = /^([^/]+)\.(dff|txd)$/i.exec(name);
+    if (!match) continue;
+    const entry = out.get(match[1]) || {};
+    entry[match[2].toLowerCase()] = true;
+    out.set(match[1], entry);
+  }
+  // A txd on its own is not a model.
+  for (const [id, entry] of out) if (!entry.dff) out.delete(id);
+  return out;
+}
+
+async function listBucketKeys() {
+  // Required lazily so local development needs no AWS dependency installed.
+  const { S3Client, ListObjectsV2Command } = require('@aws-sdk/client-s3');
+  const client = new S3Client({ region: process.env.AWS_REGION });
+
+  const keys = [];
+  let token;
+  do {
+    const page = await client.send(
+      new ListObjectsV2Command({ Bucket: S3_BUCKET, Prefix: S3_PREFIX, ContinuationToken: token })
+    );
+    for (const object of page.Contents || []) keys.push(object.Key);
+    token = page.IsTruncated ? page.NextContinuationToken : undefined;
+  } while (token);
+  return keys;
+}
+
+function listLocalKeys() {
+  if (!fs.existsSync(MODEL_ROOT)) return [];
+  return fs.readdirSync(MODEL_ROOT, { withFileTypes: true })
+    .filter((entry) => entry.isFile())
+    .map((entry) => entry.name);
+}
+
+async function refreshIndex() {
+  try {
+    index = S3_BUCKET
+      ? buildIndex(await listBucketKeys(), S3_PREFIX)
+      : buildIndex(listLocalKeys(), '');
+    indexError = null;
+  } catch (err) {
+    // Keep serving the previous index rather than going dark on a transient
+    // S3 error; the next refresh will pick it up.
+    indexError = err.message;
+    console.error('model index refresh failed:', err.message);
+  }
+}
+
+app.use(express.static(path.join(__dirname, 'public'), { index: false }));
+
+// In production the model files come from S3 via nginx or a CDN, so this only
+// serves them during local development.
+if (!S3_BUCKET) {
+  app.use('/models', express.static(MODEL_ROOT, { immutable: true, maxAge: '365d' }));
+}
+
+app.get('/api/skin/:id', (req, res) => {
+  const entry = index.get(req.params.id);
+  if (!entry) {
+    if (!index.size && indexError) {
+      return res.status(503).json({ error: 'Model index unavailable' });
+    }
+    return res.status(404).json({ error: `No model for "${req.params.id}"` });
+  }
+  res.json({
+    id: req.params.id,
+    name: req.params.id,
+    dff: `${MODELS_BASE_URL}/${req.params.id}.dff`,
+    txd: entry.txd ? `${MODELS_BASE_URL}/${req.params.id}.txd` : null,
+  });
+});
+
+app.get('/samp/skin/:id', (req, res) => {
+  res.sendFile(path.join(__dirname, 'public', 'viewer.html'));
+});
+
+// Nothing else exists - no root page, no catalogue.
+app.use((req, res) => res.status(404).type('text/plain').send('Not found'));
+
+refreshIndex().then(() => {
+  setInterval(refreshIndex, INDEX_REFRESH_MS).unref();
+  app.listen(PORT, () => {
+    console.log(`modelviewer  ->  http://localhost:${PORT}/samp/skin/7`);
+    console.log(`models from  ->  ${S3_BUCKET ? `s3://${S3_BUCKET}/${S3_PREFIX}` : MODEL_ROOT}`);
+    console.log(`served from  ->  ${MODELS_BASE_URL}`);
+    console.log(`indexed      ->  ${index.size} skins`);
+  });
+});