import * as path from "node:path";
import * as fs from "node:fs/promises";
import { tsImport } from "tsx/esm/api";
const root = process.cwd();

const getAllFiles = async (dir: string) => {
	const localEntries = await fs.readdir(dir, { withFileTypes: true });
	const entries = localEntries.filter((e) => e.isFile()).map((e) => e.name);
	for (const entry of localEntries) {
		if (
			entry.isDirectory() &&
			!entry.isSymbolicLink() &&
			!entry.name.startsWith(".") &&
			entry.name !== "node_modules"
		) {
			entries.push(
				...(await getAllFiles(path.join(dir, entry.name))).map(
					(fname) => path.join(entry.name, fname)
				)
			);
		}
	}
	return entries;
};

const getFilesToGenFrom = async () => {
	const allFiles = await getAllFiles(root);
	return allFiles
		.filter((fname) => fname.endsWith(".gen.ts"))
		.map((fname) => path.resolve(root, fname));
};

const filesBeingGenned: Record<string, Promise<void>> = {};

const genFromFile = async (fname: string) => {
	console.log("Processing", fname);
	const context = {
		async import(moduleName: string) {
			const fullname = path.resolve(path.dirname(fname), moduleName);
			await filesBeingGenned[fullname];
			return tsImport(fullname, import.meta.url);
		},
	};
	type CodegenContext = typeof context;
	const brain: (context: CodegenContext) => string | Promise<string> = (
		await tsImport(fname, import.meta.url)
	).default;
	const fileToWrite = fname.replace(/\.gen\.ts?$/, ".out.ts");
	await fs.writeFile(fileToWrite, await brain(context));
};

for (const file of await getFilesToGenFrom()) {
	filesBeingGenned[file] = genFromFile(file);
}