/**
 * Frontend build — mirrors the base app's esbuild style (vanilla TS → ESM bundle). Emits
 * public/build/{app.js, index.html, styles.css}. index.html + styles.css are copied verbatim
 * (index.html already references ./app.js and ./styles.css, both siblings in the build dir).
 */
import { build } from 'esbuild'
import { mkdir, copyFile } from 'node:fs/promises'
import { dirname, resolve } from 'node:path'
import { fileURLToPath } from 'node:url'

const here = dirname(fileURLToPath(import.meta.url))
const pub = resolve(here, 'public')
const out = resolve(pub, 'build')

async function main() {
  await mkdir(out, { recursive: true })

  await build({
    entryPoints: [resolve(pub, 'app.ts')],
    bundle: true,
    format: 'esm',
    target: 'es2022',
    minify: true,
    sourcemap: true,
    outfile: resolve(out, 'app.js'),
    logLevel: 'info',
  })

  await copyFile(resolve(pub, 'index.html'), resolve(out, 'index.html'))
  await copyFile(resolve(pub, 'styles.css'), resolve(out, 'styles.css'))
  process.stdout.write('[control-panel] frontend build → public/build\n')
}

main().catch((err) => {
  process.stderr.write(`[control-panel] build failed: ${err instanceof Error ? err.message : String(err)}\n`)
  process.exit(1)
})