import { lstat, readFile, readlink, rm } from "node:fs/promises";
import { join } from "node:path";

import { COMMAND_SHIM_MARKER } from "./command-shim.mjs";

const LEGACY_CODEX_COMPONENT_BINS = [
	{ name: "codex-comment-checker", component: "comment-checker" },
	{ name: "codex-rules", component: "rules" },
	{ name: "codex-start-work-continuation", component: "start-work-continuation" },
	{ name: "codex-telemetry", component: "telemetry" },
	{ name: "codex-ultrawork", component: "ultrawork" },
];

export async function removeLegacyCodexComponentBins(binDir, platform) {
	for (const entry of LEGACY_CODEX_COMPONENT_BINS) {
		const linkPath = join(binDir, platform === "win32" ? `${entry.name}.cmd` : entry.name);
		await removeLegacyCodexComponentBin(linkPath, entry.component, platform);
	}
}

async function removeLegacyCodexComponentBin(linkPath, component, platform) {
	try {
		const stat = await lstat(linkPath);
		if (platform !== "win32") {
			if (!stat.isSymbolicLink()) return;
			const target = await readlink(linkPath);
			if (isManagedLegacyComponentTarget(target, component)) await rm(linkPath, { force: true });
			return;
		}
		if (!stat.isFile()) return;
		const content = await readFile(linkPath, "utf8");
		if (content.includes(COMMAND_SHIM_MARKER)) await rm(linkPath, { force: true });
	} catch (error) {
		if (error instanceof Error && "code" in error && error.code === "ENOENT") return;
		throw error;
	}
}

function isManagedLegacyComponentTarget(target, component) {
	const parts = target.split(/[\\/]+/);
	const suffixStart = parts.length - 4;
	const suffix = parts.slice(-4);
	return (
		suffix[0] === "components" &&
		suffix[1] === component &&
		suffix[2] === "dist" &&
		suffix[3] === "cli.js" &&
		hasPluginCachePrefix(parts, suffixStart)
	);
}

function hasPluginCachePrefix(parts, endExclusive) {
	for (let index = 0; index < endExclusive - 1; index += 1) {
		if (parts[index] === "plugins" && parts[index + 1] === "cache") return true;
	}
	return false;
}