import { existsSync } from 'node:fs'
import { createRequire } from 'node:module'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'
import tailwindcss from '@tailwindcss/vite'
import vue from '@vitejs/plugin-vue'
import { defineConfig } from 'vite'

// In development the client talks to a homeserver through Vite's proxy, the
// same paths warp-web proxies in production, so the code never needs to
// know where the homeserver is. WARP_WEB_HOMESERVER points it elsewhere.
const homeserver = process.env.WARP_WEB_HOMESERVER ?? 'http://localhost:8008'

// The Rust crypto loads its .wasm relative to its own module
// (new URL(..., import.meta.url)). Vite's dependency pre-bundling moves the
// module into node_modules/.vite/deps without the .wasm, so the dev server
// answered with index.html and initRustCrypto failed. The dev server serves
// the package as it is instead. It is only matrix-js-sdk's dependency, which
// pnpm doesn't make reachable from the pre-bundled matrix-js-sdk, so it is
// aliased to the very copy matrix-js-sdk resolves. A production build is
// bundled by Rollup and needs neither.
const cryptoWasm = '@matrix-org/matrix-sdk-crypto-wasm'

function cryptoWasmDir(): string {
  const sdk = createRequire(import.meta.url).resolve('matrix-js-sdk')
  let dir = dirname(createRequire(sdk).resolve(cryptoWasm))
  while (!existsSync(join(dir, 'package.json'))) dir = dirname(dir)
  return dir
}

export default defineConfig(({ command }) => ({
  plugins: [vue(), tailwindcss()],
  resolve: {
    alias: {
      '@': fileURLToPath(new URL('./src', import.meta.url)),
      ...(command === 'serve' ? { [cryptoWasm]: cryptoWasmDir() } : {}),
    },
  },
  optimizeDeps: {
    exclude: [cryptoWasm],
  },
  build: {
    // Embedded into the warp-web binary by client/ (and the desktop app).
    outDir: 'client/build/dist',
    emptyOutDir: true,
    assetsInlineLimit: 0,
    // matrix-js-sdk is most of the bundle; it is one chunk on purpose.
    chunkSizeWarningLimit: 1500,
  },
  server: {
    port: 5175,
    proxy: {
      '/_matrix/client': { target: homeserver, changeOrigin: true },
      '/_matrix/media': { target: homeserver, changeOrigin: true },
      // Where the client finds the group call backend (rtc_foci).
      '/.well-known/matrix/client': { target: homeserver, changeOrigin: true },
    },
  },
}))