nupst/ts/actions/shutdown-action.ts

import * as fs from 'node:fs';
import { execFile } from 'node:child_process';
import { promisify } from 'node:util';
import { Action, type IActionContext } from './base-action.ts';
import { logger } from '../logger.ts';
import { SHUTDOWN, UI } from '../constants.ts';

const execFileAsync = promisify(execFile);

/**
 * ShutdownAction - Initiates system shutdown
 *
 * This action triggers a system shutdown using the standard shutdown command.
 * It includes a configurable delay to allow VMs and services to gracefully terminate.
 */
export class ShutdownAction extends Action {
  readonly type = 'shutdown';

  /**
   * Override shouldExecute to add shutdown-specific safety checks
   *
   * Key safety rules:
   * 1. Shutdown should NEVER trigger unless UPS is actually on battery
   *    (low battery while on grid power is not an emergency - it's charging)
   * 2. For power status changes, only trigger on transitions TO onBattery from online
   *    (ignore unknown → online at startup, and power restoration events)
   * 3. For threshold violations, verify UPS is on battery before acting
   *
   * @param context Action context with UPS state
   * @returns True if shutdown should execute
   */
  protected override shouldExecute(context: IActionContext): boolean {
    const mode = this.config.triggerMode || 'powerChangesAndThresholds';

    // CRITICAL SAFETY CHECK: Shutdown should NEVER trigger unless UPS is on battery
    // A low battery while on grid power is not an emergency (the battery is charging)
    if (context.powerStatus !== 'onBattery') {
      logger.info(`Shutdown action skipped: UPS is not on battery (status: ${context.powerStatus})`);
      return false;
    }

    // Handle threshold violations (UPS is confirmed on battery at this point)
    if (context.triggerReason === 'thresholdViolation') {
      // 'onlyPowerChanges' mode ignores thresholds
      if (mode === 'onlyPowerChanges') {
        logger.info('Shutdown action skipped: triggerMode is onlyPowerChanges, ignoring threshold');
        return false;
      }
      // Check if thresholds are actually exceeded
      return this.areThresholdsExceeded(context.batteryCapacity, context.batteryRuntime);
    }

    // Handle power status changes
    if (context.triggerReason === 'powerStatusChange') {
      // 'onlyThresholds' mode ignores power status changes
      if (mode === 'onlyThresholds') {
        logger.info('Shutdown action skipped: triggerMode is onlyThresholds, ignoring power change');
        return false;
      }

      const prev = context.previousPowerStatus;

      // Only trigger on transitions TO onBattery from online (real power loss)
      if (prev === 'online') {
        logger.info('Shutdown action triggered: power loss detected (online → onBattery)');
        return true;
      }

      // For unknown → onBattery (daemon started while on battery):
      // This is a startup scenario - be cautious. The user may have just started
      // the daemon for testing, or the UPS may have been on battery for a while.
      // Only trigger if mode explicitly includes power changes.
      if (prev === 'unknown') {
        if (mode === 'onlyPowerChanges' || mode === 'powerChangesAndThresholds' || mode === 'anyChange') {
          logger.info('Shutdown action triggered: UPS on battery at daemon startup (unknown → onBattery)');
          return true;
        }
        return false;
      }

      // Other transitions (e.g., onBattery → onBattery) should not trigger
      logger.info(`Shutdown action skipped: non-emergency transition (${prev} → ${context.powerStatus})`);
      return false;
    }

    // For 'anyChange' mode, always execute (UPS is already confirmed on battery)
    if (mode === 'anyChange') {
      return true;
    }

    return false;
  }

  /**
   * Execute the shutdown action
   * @param context Action context with UPS state
   */
  async execute(context: IActionContext): Promise<void> {
    // Check if we should execute based on trigger mode and thresholds
    if (!this.shouldExecute(context)) {
      logger.info(`Shutdown action skipped (trigger mode: ${this.config.triggerMode || 'powerChangesAndThresholds'})`);
      return;
    }

    const shutdownDelay = this.config.shutdownDelay || SHUTDOWN.DEFAULT_DELAY_MINUTES;

    logger.log('');
    logger.logBoxTitle('Initiating System Shutdown', UI.WIDE_BOX_WIDTH, 'error');
    logger.logBoxLine(`UPS: ${context.upsName} (${context.upsId})`);
    logger.logBoxLine(`Power Status: ${context.powerStatus}`);
    logger.logBoxLine(`Battery: ${context.batteryCapacity}%`);
    logger.logBoxLine(`Runtime: ${context.batteryRuntime} minutes`);
    logger.logBoxLine(`Trigger: ${context.triggerReason}`);
    logger.logBoxLine(`Shutdown delay: ${shutdownDelay} minutes`);
    logger.logBoxEnd();
    logger.log('');

    try {
      await this.executeShutdownCommand(shutdownDelay);
    } catch (error) {
      logger.error(
        `Shutdown command failed: ${error instanceof Error ? error.message : String(error)}`,
      );
      // Try alternative methods
      await this.tryAlternativeShutdownMethods();
    }
  }

  /**
   * Execute the primary shutdown command
   * @param delayMinutes Minutes to delay before shutdown
   */
  private async executeShutdownCommand(delayMinutes: number): Promise<void> {
    // Find shutdown command in common system paths
    const shutdownPaths = [
      '/sbin/shutdown',
      '/usr/sbin/shutdown',
      '/bin/shutdown',
      '/usr/bin/shutdown',
    ];

    let shutdownCmd = '';
    for (const path of shutdownPaths) {
      try {
        if (fs.existsSync(path)) {
          shutdownCmd = path;
          logger.log(`Found shutdown command at: ${shutdownCmd}`);
          break;
        }
      } catch (_e) {
        // Continue checking other paths
      }
    }

    if (shutdownCmd) {
      // Execute shutdown command with delay to allow for VM graceful shutdown
      const message = `UPS battery critical, shutting down in ${delayMinutes} minutes`;
      logger.log(`Executing: ${shutdownCmd} -h +${delayMinutes} "${message}"`);

      const { stdout } = await execFileAsync(shutdownCmd, [
        '-h',
        `+${delayMinutes}`,
        message,
      ]);

      logger.log(`Shutdown initiated: ${stdout}`);
      logger.log(`Allowing ${delayMinutes} minutes for VMs to shut down safely`);
    } else {
      throw new Error('Shutdown command not found in common paths');
    }
  }

  /**
   * Try alternative shutdown methods if primary command fails
   */
  private async tryAlternativeShutdownMethods(): Promise<void> {
    logger.error('Trying alternative shutdown methods...');

    const alternatives = [
      { cmd: 'poweroff', args: ['--force'] },
      { cmd: 'halt', args: ['-p'] },
      { cmd: 'systemctl', args: ['poweroff'] },
      { cmd: 'reboot', args: ['-p'] }, // Some systems allow reboot -p for power off
    ];

    for (const alt of alternatives) {
      try {
        // First check if command exists in common system paths
        const paths = [
          `/sbin/${alt.cmd}`,
          `/usr/sbin/${alt.cmd}`,
          `/bin/${alt.cmd}`,
          `/usr/bin/${alt.cmd}`,
        ];

        let cmdPath = '';
        for (const path of paths) {
          if (fs.existsSync(path)) {
            cmdPath = path;
            break;
          }
        }

        if (cmdPath) {
          logger.log(`Trying alternative shutdown method: ${cmdPath} ${alt.args.join(' ')}`);
          await execFileAsync(cmdPath, alt.args);
          logger.log(`Alternative method ${alt.cmd} succeeded`);
          return; // Exit if successful
        }
      } catch (_altError) {
        logger.error(`Alternative method ${alt.cmd} failed`);
        // Continue to next method
      }
    }

    logger.error('All shutdown methods failed');
  }
}