import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import { promises as fs } from 'node:fs'
import path from 'node:path'
import { gzip } from 'node:zlib'
import { promisify } from 'node:util'

const gzipAsync = promisify(gzip)

// Emit pre-compressed assets so Nginx can serve them with `gzip_static on`.
function gzipAssets() {
  const compressibleExtensions = new Set(['.html', '.css', '.js', '.mjs', '.json', '.svg', '.txt', '.xml'])

  return {
    name: 'gzip-assets',
    apply: 'build',
    async closeBundle() {
      const outputDir = path.resolve(process.cwd(), 'dist')

      async function compressDirectory(directory) {
        const entries = await fs.readdir(directory, { withFileTypes: true })

        await Promise.all(entries.map(async (entry) => {
          const filePath = path.join(directory, entry.name)

          if (entry.isDirectory()) {
            await compressDirectory(filePath)
            return
          }

          if (!compressibleExtensions.has(path.extname(entry.name).toLowerCase())) {
            return
          }

          const source = await fs.readFile(filePath)
          const compressed = await gzipAsync(source, { level: 9 })
          await fs.writeFile(`${filePath}.gz`, compressed)
        }))
      }

      await compressDirectory(outputDir)
    },
  }
}

export default defineConfig({
  plugins: [react(), gzipAssets()],
  server: {
    host: '0.0.0.0',
    port: 5173,
  },
})