import { realpath } from "node:fs/promises";

/** Origin host names may be SSH aliases; the repository coordinates must match. */
export async function verifiedCheckout(
	repository: { owner: string; name: string },
	checkouts: string[],
	preferred?: string,
): Promise<string | undefined> {
	for (let candidate of preferred === undefined ? checkouts : [preferred, ...checkouts]) {
		try {
			let cwd = await realpath(candidate);
			let git = async (...args: string[]) => {
				let process = Bun.spawn(["git", "-C", cwd, ...args], {
					stdout: "pipe",
					stderr: "pipe",
				});
				let output = await new Response(process.stdout).text();
				if (await process.exited !== 0) throw new Error("not a checkout");
				return output.trim();
			};
			if (await git("rev-parse", "--is-inside-work-tree") !== "true") continue;
			let origin = await git("remote", "get-url", "origin");
			let path = origin.includes("://")
				? new URL(origin).pathname.replace(/^\//, "")
				: /^[^/:]+:(.+)$/.exec(origin)?.[1];
			if (
				path?.replace(/\.git$/, "").toLowerCase()
					=== `${repository.owner}/${repository.name}`.toLowerCase()
			) {
				return cwd;
			}
		} catch {
			// A missing or unrelated checkout retains the isolated Planner boundary.
		}
	}
	return undefined;
}