import { execFileSync } from "node:child_process";
import { cpSync, existsSync, rmSync, writeFileSync } from "node:fs";
import { join } from "node:path";

const BRANCH = process.env.BETA_DOCS_BRANCH ?? "next";
const REPO =
	process.env.BETA_DOCS_REPO ??
	"https://github.com/better-auth/better-auth.git";
const REMOTE_PATH = "docs/content/docs";
const DEST = "content/docs-beta";
const TMP = ".beta-sync-tmp";

if (process.env.BETA_DOCS_SKIP === "1") {
	console.log("[sync-beta] skipped (BETA_DOCS_SKIP=1)");
	process.exit(0);
}

function git(args: string[], cwd?: string) {
	execFileSync("git", args, { stdio: "inherit", cwd });
}

console.log(`[sync-beta] ${BRANCH}:${REMOTE_PATH} → ${DEST}`);

try {
	rmSync(TMP, { recursive: true, force: true });

	// Sparse + blobless shallow clone fetches only the target directory.
	git([
		"clone",
		"--depth=1",
		`--branch=${BRANCH}`,
		"--filter=blob:none",
		"--sparse",
		REPO,
		TMP,
	]);
	git(["-C", TMP, "sparse-checkout", "set", REMOTE_PATH]);

	const srcPath = join(TMP, REMOTE_PATH);
	if (!existsSync(srcPath)) {
		throw new Error(`Source path not found after sparse checkout: ${srcPath}`);
	}

	rmSync(DEST, { recursive: true, force: true });
	cpSync(srcPath, DEST, { recursive: true });
	// Preserve the tracked .gitkeep so fumadocs-mdx can find the collection
	// on a fresh clone before this script has run.
	writeFileSync(join(DEST, ".gitkeep"), "");

	console.log("[sync-beta] done");
} finally {
	rmSync(TMP, { recursive: true, force: true });
}