import path from 'node:path';
import process from 'node:process';
import adapter from '@sveltejs/adapter-static';
import { vitePreprocess } from '@sveltejs/vite-plugin-svelte';

// OUT_DIR is set by Cargo at build time:
// <https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-build-scripts>
//
// When we're building through `vite` directly, it will not be set; we use "target" as a generic
// output directory to keep all the build products in one place.
const outDir = process.env['OUT_DIR'] ?? 'target';

/** @type {import('@sveltejs/kit').Config} */
const config = {
  kit: {
    adapter: adapter({
      pages: path.join(outDir, 'ui'),
      fallback: 'index.html',
    }),
    files: {
      hooks: {
        universal: 'ui/hooks',
        server: 'ui/hooks.server',
        client: 'ui/hooks.client',
      },
      assets: 'ui/static',
      lib: 'ui/lib',
      params: 'ui/params',
      routes: 'ui/routes',
      serviceWorker: 'ui/service-worker',
      appTemplate: 'ui/app.html',
      errorTemplate: 'ui/error.html',
    },
    outDir: path.join(outDir, 'svelte-kit'),
  },
  preprocess: vitePreprocess(),
};

export default config;