/**
 * Vite build configuration and PWA asset emission.
 *
 * The same per-build identifier is compiled into the browser bundle and the
 * service worker. This makes an hourly/visibility update check discover a new
 * deployment while still leaving activation under explicit user control.
 */
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import { readFileSync } from 'node:fs'

// A new URL makes the browser check and stage every deployed service worker.
// The waiting worker is still activated explicitly by the user in the console.
const pwaBuildId = Date.now().toString(36)
const serviceWorkerSource = readFileSync(new URL('./pwa/control-sw.js', import.meta.url), 'utf8')

export default defineConfig({
  plugins: [
    react(),
    {
      name: 'control-pwa-assets',
      generateBundle() {
        this.emitFile({
          type: 'asset',
          fileName: 'control/sw.js',
          source: serviceWorkerSource.replaceAll('__PWA_BUILD_ID__', pwaBuildId),
        })
      },
    },
  ],
  define: {
    __PWA_BUILD_ID__: JSON.stringify(pwaBuildId),
  },
})