#!/usr/bin/env node
import { spawn } from "node:child_process";
import { realpathSync } from "node:fs";
import { dirname, join, resolve } from "node:path";
import { fileURLToPath } from "node:url";

const piPackageCommands = new Set(["install", "remove", "uninstall", "update", "list", "config"]);

export function resolvePackageRootFromCliUrl(cliUrl: string): string {
	return dirname(dirname(fileURLToPath(cliUrl)));
}

export function resolvePiCliPath(piEntrypointUrl: string): string {
	return join(dirname(fileURLToPath(piEntrypointUrl)), "cli.js");
}

export function shouldInjectLinlicPackage(userArgs: string[]): boolean {
	return !piPackageCommands.has(userArgs[0] ?? "");
}

export function buildPiArgs(packageRoot: string, userArgs: string[]): string[] {
	if (!shouldInjectLinlicPackage(userArgs)) {
		return userArgs;
	}
	return ["--extension", packageRoot, ...userArgs];
}

function resolveExecutablePath(path: string): string {
	const resolvedPath = resolve(path);
	try {
		return realpathSync(resolvedPath);
	} catch {
		return resolvedPath;
	}
}

export function isMainModule(moduleUrl: string, argvPath = process.argv[1]): boolean {
	return argvPath ? resolveExecutablePath(fileURLToPath(moduleUrl)) === resolveExecutablePath(argvPath) : false;
}

export async function runPiCli(options: {
	piCliPath: string;
	packageRoot: string;
	userArgs: string[];
	env?: NodeJS.ProcessEnv;
}): Promise<number> {
	const child = spawn(process.execPath, [options.piCliPath, ...buildPiArgs(options.packageRoot, options.userArgs)], {
		stdio: "inherit",
		env: { ...process.env, ...options.env, LINLIC_AGENT: "true" },
	});

	return new Promise((resolveExitCode) => {
		child.on("error", (error) => {
			console.error(`linlic-agent failed to start Pi CLI: ${error.message}`);
			resolveExitCode(1);
		});
		child.on("exit", (code, signal) => {
			if (signal) {
				process.kill(process.pid, signal);
				resolveExitCode(1);
				return;
			}
			resolveExitCode(code ?? 0);
		});
	});
}

if (isMainModule(import.meta.url)) {
	const packageRoot = resolvePackageRootFromCliUrl(import.meta.url);
	const piCliPath = resolvePiCliPath(import.meta.resolve("@earendil-works/pi-coding-agent"));
	process.exitCode = await runPiCli({
		piCliPath,
		packageRoot,
		userArgs: process.argv.slice(2),
	});
}