import fs from 'node:fs';
import { createRequire } from 'node:module';
import replace from '@rollup/plugin-replace';
import resolve from '@rollup/plugin-node-resolve';
import commonjs from '@rollup/plugin-commonjs';
import json from '@rollup/plugin-json';

const require = createRequire(import.meta.url);
const pkg = JSON.parse(fs.readFileSync('package.json', 'utf-8'));

// Create auto-generated .js files
fs.writeFileSync(
	'./src/shared/version.js',
	`/** @type {string} */\nexport const VERSION = '${pkg.version}';`
);

const internal = await import('./src/runtime/internal/index.js');
fs.writeFileSync(
	'src/compiler/compile/internal_exports.js',
	`// This file is automatically generated\n` +
		`export default new Set(${JSON.stringify(Object.keys(internal))});`
);

// Generate d.ts files for runtime entrypoints so that TS can find it also without `"moduleResolution": "bundler"`
fs.readdirSync('src/runtime', { withFileTypes: true })
	.filter((dirent) => dirent.isDirectory())
	.forEach((dirent) =>
		fs.writeFileSync(
			`${dirent.name}.d.ts`,
			`export * from './types/runtime/${dirent.name}/index.js';`
		)
	);

fs.writeFileSync('./index.d.ts', `export * from './types/runtime/index.js';`);

fs.writeFileSync(
	'./compiler.d.ts',
	`export { compile, parse, preprocess, walk, VERSION } from './types/compiler/index.js';`
);

/**
 * @type {import("rollup").RollupOptions[]}
 */
export default [
	// Generate UMD build of the compiler so that Eslint/Prettier (which need CJS) and REPL (which needs UMD because browser) can use it
	{
		input: 'src/compiler/index.js',
		plugins: [
			replace({
				preventAssignment: true,
				values: {
					'process.env.NODE_DEBUG': false // appears inside the util package
				}
			}),
			{
				resolveId(id) {
					// util is a built-in module in Node.js, but we want a self-contained compiler bundle
					// that also works in the browser, so we load its polyfill instead
					if (id === 'util') {
						return require.resolve('./node_modules/util'); // just 'utils' would resolve this to the built-in module
					}
					// Must import from the `css-tree` browser bundled distribution due to `createRequire` usage if importing from css-tree directly
					if (id === 'css-tree') {
						return require.resolve('./node_modules/css-tree/dist/csstree.esm.js');
					}
				}
			},
			resolve(),
			commonjs({
				include: ['node_modules/**']
			}),
			json()
		],
		output: {
			file: 'compiler.cjs',
			format: 'umd',
			name: 'svelte',
			sourcemap: false
		},
		external: []
	}
];