import path from "node:path";
import { execPath, platform } from "node:process";
import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";

interface NpmCommandResolutionOptions {
	platform?: NodeJS.Platform;
	nodeExecPath?: string;
}

interface NpmExecOptions {
	timeout: number;
	signal?: AbortSignal;
}

function getNpmCliPath(nodeExecPath: string, runtimePlatform: NodeJS.Platform): string {
	const pathImpl = runtimePlatform === "win32" ? path.win32 : path;
	return pathImpl.join(pathImpl.dirname(nodeExecPath), "node_modules", "npm", "bin", "npm-cli.js");
}

export function resolveNpmCommand(
	npmArgs: string[],
	options?: NpmCommandResolutionOptions,
): { command: string; args: string[] } {
	const runtimePlatform = options?.platform ?? platform;

	if (runtimePlatform === "win32") {
		const nodeBinary = options?.nodeExecPath ?? execPath;
		return {
			command: nodeBinary,
			args: [getNpmCliPath(nodeBinary, runtimePlatform), ...npmArgs],
		};
	}

	return { command: "npm", args: npmArgs };
}

export async function execNpm(
	pi: ExtensionAPI,
	npmArgs: string[],
	ctx: { cwd: string },
	options: NpmExecOptions,
): Promise<{ code: number; stdout: string; stderr: string; killed: boolean }> {
	const resolved = resolveNpmCommand(npmArgs);
	return pi.exec(resolved.command, resolved.args, {
		timeout: options.timeout,
		cwd: ctx.cwd,
		...(options.signal ? { signal: options.signal } : {}),
	});
}