import * as esbuild from "esbuild";
import { default as glob } from "tiny-glob";
import { promises as fs } from "node:fs";
import { extname, resolve, relative, dirname } from "node:path";
import { fileURLToPath } from "node:url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

const watch = process.argv.at(-1) === "--watch";

// plugin that rewrites the import paths so in typescript we can use
//
//    import smth from src/index.ts
//
// instead of providing relative paths
const handle_absolute_paths = (project_dir) => ({
	name: "sealgen-rewrite-asset-imports",
	setup(build) {
		build.onLoad({ filter: /\.tsx?$/ }, async (args) => {
			let contents = await fs.readFile(args.path, "utf8");
			const regex_import = new RegExp(
				`^import ([^ ]+, )?(\\w+|{[^}]+}) from "([^"]+)";`,
				"gm"
			);
			contents = contents.replaceAll(regex_import, (line) => {
				const replaced = line.replace(
					`"src/`,
					`"` +
						relative(args.path, resolve(project_dir, "./lib/src")) +
						"/"
				);
				return replaced;
			});
			return {
				contents,
				loader: extname(args.path) === ".tsx" ? "tsx" : "ts",
			};
		});
	},
});

(async () => {
	let entryPoints = Object.fromEntries(
		(await glob("./src/**/*.ts")).map((e) => [e.replace(/\.ts$/, ""), e])
	);
	
	const buildOptions = {
		entryPoints,
		sourcemap: true,
		bundle: false,
		outdir: "./lib",
		logLevel: "info",
		platform: "node",
		target: "es2022",
		format: "esm",
		plugins: [handle_absolute_paths(__dirname)],
	};
	
	if (watch) {
		const context = await esbuild.context(buildOptions);
		await context.watch();
	} else {
		await esbuild.build(buildOptions);
	}
})();