import { defineConfig, type Plugin, type UserConfig } from 'vite'
import react from '@vitejs/plugin-react'
import tsconfigPaths from 'vite-tsconfig-paths'
import { VitePWA } from 'vite-plugin-pwa';
import * as path from 'path' // ✅ Import path module
import { readFileSync, renameSync, existsSync, unlinkSync } from 'node:fs'
import { fileURLToPath } from 'node:url'
import { execSync } from 'node:child_process'

const rootDir = path.dirname(fileURLToPath(import.meta.url))

const LOCALNET_MODE = 'localnet'

/** Dev server: serve the minimal LAN shell (indexLocal.html) instead of the full index with third-party bootstraps. */
function useLocalnetShellHtml (mode: string, command: string): Plugin {
  if (mode !== LOCALNET_MODE || command !== 'serve') {
    return { name: 'localnet-shell-html-noop' }
  }
  return {
    name: 'localnet-shell-html',
    apply: 'serve',
    transformIndexHtml: {
      order: 'pre',
      handler () {
        return readFileSync(path.join(rootDir, 'indexLocal.html'), 'utf-8')
      },
    },
  }
}

/** After build, LAN shell is emitted as indexLocal.html; rename to index.html so nginx and PWA still use /. */
function emitLocalnetShellAsIndexHtml (mode: string): Plugin {
  if (mode !== LOCALNET_MODE) {
    return { name: 'emit-localnet-shell-as-index-noop' }
  }
  return {
    name: 'emit-localnet-shell-as-index-html',
    closeBundle () {
      const outDir = path.join(rootDir, 'build')
      const from = path.join(outDir, 'indexLocal.html')
      const to = path.join(outDir, 'index.html')
      if (existsSync(from)) {
        if (existsSync(to)) unlinkSync(to)
        renameSync(from, to)
      }
    },
  }
}

// https://vitejs.dev/config/
export default defineConfig(({ command, mode }): UserConfig => {
  const useLocalnetShell = mode === LOCALNET_MODE

  let gitHash = 'unknown'
  try {
    gitHash = execSync('git rev-parse --short HEAD').toString().trim()
  } catch {}

  const buildDate = new Date().toISOString()

  return {
  define: {
    __BUILD_DATE__: JSON.stringify(buildDate),
    __GIT_HASH__: JSON.stringify(gitHash),
  },
  plugins: [
    useLocalnetShellHtml(mode, command),
    emitLocalnetShellAsIndexHtml(mode),
    react(), 
    tsconfigPaths(),
    VitePWA({
      registerType: 'autoUpdate', // Automatically updates the service worker when a new version is available
      workbox: {
        skipWaiting: true, //makes the new worker call skip waiting
        clientsClaim: true, //makes it claim control of clients as soon as it activates
        globPatterns: ['**/*.{js,css,html,png,jpg,svg}'], // Cache all common asset types
        maximumFileSizeToCacheInBytes: 20 * 1024 * 1024, // 20 MiB
        cleanupOutdatedCaches: true,
        navigateFallback: "/index.html",
        runtimeCaching: [
          {
            urlPattern: ({ request }) => request.destination === 'document',
            handler: 'NetworkFirst',
            options: {
              cacheName: 'html-cache',
            },
          },
          {
            urlPattern: ({ request }) =>
              ['style', 'script', 'worker'].includes(request.destination),
            handler: 'StaleWhileRevalidate',
            options: {
              cacheName: 'assets-cache',
            },
          },
          {
            //this forces all api calls to go through the network
            urlPattern: ({ url }) => url.pathname.startsWith('/v1/'),
            handler: 'NetworkOnly',
            options: {
              cacheName: 'api-cache',
            },
          },
        ]
      },
    }),
  ],
  build: {
    outDir: './build',
    sourcemap: true,
    minify: false,
    target: 'esnext',
    rollupOptions: {
      input: {
        main: path.join(
          rootDir,
          useLocalnetShell ? 'indexLocal.html' : 'index.html'
        ),
      },
    }
  },
  esbuild: {
    keepNames: true, // Prevent function name mangling
  },
  }
})