import _locreq from "locreq";
import { promises as fs } from "fs";
import { assertType, predicates } from "@sealcode/ts-predicates";
import { formatWithPrettier } from "./utils/prettier.js";

const target_locreq = _locreq(process.cwd());

export async function extractCollectionClassname(
	full_file_path: string
): Promise<string> {
	const file_content = await fs.readFile(full_file_path, "utf-8");
	const result = /export default class (\w+)/.exec(file_content);
	if (result === null) {
		throw new Error("Missing 'export default class' statement?");
	}
	return assertType(
		result[1],
		predicates.string,
		`Missing export default class in '${full_file_path}'?`
	);
}

export async function generateCollections(): Promise<void> {
	const collections_dir = target_locreq.resolve("src/back/collections");
	const files = (await fs.readdir(collections_dir)).filter(
		(f) =>
			!/\.(sub)?test\./.exec(f) &&
			f != "collections.ts" &&
			!f.includes(".#") &&
			f.endsWith(".ts")
	);
	const file_data = await Promise.all(
		files.map(async (file) => {
			const full_path = target_locreq.resolve(
				"src/back/collections/" + file
			);
			const class_name = await extractCollectionClassname(full_path);
			return {
				class_name,
				file,
				full_path,
				urlname: file.replace(".ts", ""),
			};
		})
	);

	const content = `// DO NOT EDIT! This file is generated automaticaly with 'npm run generate-collections'
import { App } from "sealious";

${file_data
	.map(
		({ class_name, urlname }) =>
			`import _${class_name} from "./${urlname}.js";`
	)
	.join("\n")}
	
${file_data
	.map(
		({ class_name }) => `export const ${class_name} = new _${class_name}();`
	)
	.join("\n")}

export const collections = {
	...App.BaseCollections,
${file_data
	.map(({ class_name, urlname }) => `	"${urlname}": ${class_name},`)
	.join("\n")}
};`;
	await fs.writeFile(
		target_locreq.resolve("src/back/collections/collections.ts"),
		await formatWithPrettier(content)
	);
	// eslint-disable-next-line no-console
	console.log(
		"Successfuly generated new src/back/collections/collections.ts file"
	);
}