import { spawn, type ChildProcess } from 'child_process';
import { existsSync } from 'fs';

export interface ManagedMonitorConfig {
  managedMonitor?: string;
  monitor_port?: number;
  logLevel?: string;
}

let monitorProcess: ChildProcess | null = null;

export function startManagedMonitor(
  logger: { info: (...args: any[]) => void; warn: (...args: any[]) => void; error: (...args: any[]) => void },
  config: ManagedMonitorConfig,
): void {
  if (!config.managedMonitor) return;
  if (monitorProcess) {
    logger.info('HarborForge managed monitor already running');
    return;
  }
  if (!existsSync(config.managedMonitor)) {
    logger.warn(`HarborForge managed monitor path not found: ${config.managedMonitor}`);
    return;
  }

  const args: string[] = [];
  if (config.monitor_port) args.push('--port', String(config.monitor_port));
  if (config.logLevel) args.push('--log-level', String(config.logLevel));

  monitorProcess = spawn(config.managedMonitor, args, {
    stdio: 'inherit',
    detached: false,
  });

  monitorProcess.on('exit', (code, signal) => {
    logger.warn(`HarborForge managed monitor exited code=${code ?? 'null'} signal=${signal ?? 'null'}`);
    monitorProcess = null;
  });

  logger.info(`HarborForge managed monitor started: ${config.managedMonitor}`);
}

export function stopManagedMonitor(
  logger: { info: (...args: any[]) => void; warn: (...args: any[]) => void },
): void {
  if (!monitorProcess) return;
  const pid = monitorProcess.pid;
  monitorProcess.kill('SIGTERM');
  monitorProcess = null;
  logger.info(`HarborForge managed monitor stopped pid=${pid ?? 'unknown'}`);
}