import { readdirSync, readFileSync, rmSync, statSync } from 'node:fs';
import { join, resolve } from 'node:path';
import { gzipSync } from 'node:zlib';

import { svelte } from '@sveltejs/vite-plugin-svelte';
import { build } from 'vite';

const root = process.cwd();
const outDir = resolve(root, 'build/.bundle-smoke');
const virtualId = 'virtual:active-app-smoke';
const resolvedVirtualId = `\0${virtualId}`;
const maxGzipKb = Number(process.env.ACTIVE_BUNDLE_GZIP_LIMIT_KB ?? 70);

// Aliases mirror `svelte.config.js`. Specific subpaths must come before
// the parent alias — Vite's resolver matches by prefix.
const alias = {
	'$active-app/services': resolve(root, 'src/arts/active-app/service-factories'),
	'$active-app/presets': resolve(root, 'src/arts/active-app/presets'),
	'$active-app': resolve(root, 'src/arts/active-app'),
	$adom: resolve(root, 'src/arts/adom'),
	$auth: resolve(root, 'src/arts/auth'),
	$bus: resolve(root, 'src/arts/bus'),
	$cache: resolve(root, 'src/arts/cache'),
	$connection: resolve(root, 'src/arts/connection'),
	$frontend: resolve(root, 'src/arts/frontend'),
	$libs: resolve(root, 'src/libs'),
	$locale: resolve(root, 'src/libs/locale'),
	$reactive: resolve(root, 'src/libs/reactive'),
	$format: resolve(root, 'src/arts/format'),
	$http: resolve(root, 'src/arts/http'),
	$lang: resolve(root, 'src/arts/lang'),
	$logger: resolve(root, 'src/arts/logger'),
	$orca: resolve(root, 'src/arts/orca'),
	$perm: resolve(root, 'src/arts/perm'),
	$prefs: resolve(root, 'src/arts/prefs'),
	$session: resolve(root, 'src/arts/session'),
	$sium: resolve(root, 'src/arts/sium'),
	$storage: resolve(root, 'src/arts/storage'),
	$svrs: resolve(root, 'src/svrs'),
	$timer: resolve(root, 'src/arts/timer')
};

rmSync(outDir, { recursive: true, force: true });

await build({
	root,
	configFile: false,
	logLevel: 'silent',
	plugins: [
		svelte({ compilerOptions: { runes: true } }),
		{
			name: 'active-app-smoke-entry',
			resolveId(id) {
				return id === virtualId ? resolvedVirtualId : undefined;
			},
			load(id) {
				if (id !== resolvedVirtualId) return undefined;
				return [
					"import { createActiveApp } from '$active-app/active-app.svelte';",
					"import { LogLevel } from '$logger/types';",
					'const App = createActiveApp({ logger: { level: LogLevel.NONE, transports: [] } });',
					'App.dispose();',
					'export default App;'
				].join('\n');
			}
		}
	],
	resolve: { alias },
	build: {
		emptyOutDir: true,
		minify: 'oxc',
		outDir,
		rollupOptions: {
			input: virtualId,
			output: {
				chunkFileNames: 'chunks/[name]-[hash].js',
				entryFileNames: 'entry.js',
				format: 'es'
			}
		},
		sourcemap: false
	}
});

const jsFiles = listFiles(outDir).filter((file) => file.endsWith('.js'));
const rawBytes = jsFiles.reduce((sum, file) => sum + statSync(file).size, 0);
const gzBytes = gzipSync(Buffer.concat(jsFiles.map((file) => readFileSync(file)))).byteLength;
const rawKb = bytesToKb(rawBytes);
const gzKb = bytesToKb(gzBytes);

console.log(
	`active bundle smoke: ${gzKb.toFixed(2)} KB gzip (${rawKb.toFixed(2)} KB raw, ${jsFiles.length} JS file)`
);

if (gzKb > maxGzipKb) {
	console.error(
		`active bundle smoke exceeded ${maxGzipKb.toFixed(2)} KB gzip. Current: ${gzKb.toFixed(2)} KB.`
	);
	process.exitCode = 1;
}

function listFiles(dir) {
	return readdirSync(dir, { withFileTypes: true }).flatMap((entry) => {
		const path = join(dir, entry.name);
		return entry.isDirectory() ? listFiles(path) : [path];
	});
}

function bytesToKb(bytes) {
	return bytes / 1024;
}