import * as fs from "node:fs";
import * as path from "node:path";

export function getPiInvocation(args: string[]): {
	command: string;
	args: string[];
} {
	const currentScript = process.argv[1];
	const isBunVirtualScript = currentScript?.startsWith("/$bunfs/root/");

	if (
		currentScript &&
		!isBunVirtualScript &&
		fs.existsSync(currentScript) &&
		isPiEntrypoint(currentScript)
	) {
		return { command: process.execPath, args: [currentScript, ...args] };
	}

	const execName = path.basename(process.execPath).toLowerCase();
	const isGenericRuntime = /^(node|bun)(\.exe)?$/.test(execName);
	if (!isGenericRuntime) {
		return { command: process.execPath, args };
	}

	return { command: "pi", args };
}

function isPiEntrypoint(scriptPath: string): boolean {
	const scriptName = path.basename(scriptPath).toLowerCase();
	return (
		/^pi(\.(cjs|js|mjs|ts))?$/.test(scriptName) ||
		(scriptName === "cli.js" && scriptPath.includes("pi-coding-agent"))
	);
}