import { Client } from 'ssh2';

import fs from 'fs';

const KEY_PATH = process.env.ZPM_SSH_KEY || '/root/.ssh/id_ed25519';

export interface SSHResult { code: number; stdout: string; stderr: string; }

export function runSSH(host: string, user: string, command: string, timeoutMs = 120_000): Promise<SSHResult> {

  return new Promise((resolve, reject) => {

    const conn = new Client();

    let stdout = '';

    let stderr = '';

    let settled = false;

    const done = (fn: () => void) => { if (!settled) { settled = true; clearTimeout(timer); try { conn.end(); } catch {} fn(); } };

    const timer = setTimeout(() => done(() => reject(new Error(`ssh timeout after ${timeoutMs}ms`))), timeoutMs);

    conn

      .on('ready', () => {

        conn.exec(command, (err, stream) => {

          if (err) return done(() => reject(err));

          stream

            .on('close', (code: number) => done(() => resolve({ code: code ?? 0, stdout, stderr })))

            .on('data', (d: Buffer) => { stdout += d.toString(); })

            .stderr.on('data', (d: Buffer) => { stderr += d.toString(); });

        });

      })

      .on('error', (e) => done(() => reject(e)))

      .connect({ host, port: 22, username: user, privateKey: fs.readFileSync(KEY_PATH), readyTimeout: Math.min(timeoutMs, 20_000) });

  });

}

export const b64 = (s: string) => Buffer.from(s, 'utf8').toString('base64');