feat: serve built SPA with fallback and artwork cache

server/src/app.ts

@@ -1,6 +1,9 @@
 import Fastify, { FastifyInstance } from 'fastify'
 import Database from 'better-sqlite3'
 import cookie from '@fastify/cookie'
+import fastifyStatic from '@fastify/static'
+import path from 'node:path'
+import { existsSync } from 'node:fs'
 import type { Config } from './config.js'
 import { SerialQueue } from './queue.js'
 import { SyncManager } from './sync.js'
@@ -27,6 +30,8 @@ export interface AppOptions {
   db: Database.Database
   config: Config
   fetchImpl?: typeof fetch
+  /** Directory of the built SPA. Defaults to web/dist when it exists. */
+  webDist?: string
 }
 
 export async function buildApp(opts: AppOptions): Promise<FastifyInstance> {
@@ -44,6 +49,30 @@ export async function buildApp(opts: AppOptions): Promise<FastifyInstance> {
   await registerCollectionRoutes(app)
   await registerLibraryRoutes(app)
 
+  // artwork cache (always available)
+  await app.register(fastifyStatic, {
+    root: opts.config.artworkDir,
+    prefix: '/artwork/',
+    decorateReply: false,
+  })
+
+  const webDist = opts.webDist ?? path.resolve('web/dist')
+  const hasWeb = existsSync(webDist)
+  if (hasWeb) {
+    await app.register(fastifyStatic, { root: webDist, prefix: '/' })
+  }
+
+  app.setNotFoundHandler((request, reply) => {
+    const url = request.raw.url ?? ''
+    if (url.startsWith('/api')) {
+      return reply.code(404).send({ error: 'not_found' })
+    }
+    if (hasWeb) {
+      return reply.sendFile('index.html')
+    }
+    return reply.code(404).send({ error: 'not_found' })
+  })
+
   app.get('/api/health', async () => ({ ok: true }))
   return app
 }