export interface IWatchEventLike {
  kind: string;
  paths: string[];
}

export type TConfigReloadTransition = 'monitoringWillStart' | 'deviceCountChanged' | 'reloaded';

export interface IConfigReloadSnapshot {
  transition: TConfigReloadTransition;
  message: string;
  shouldInitializeUpsStatus: boolean;
  shouldLogMonitoringStart: boolean;
}

export function shouldReloadConfig(
  event: IWatchEventLike,
  configFileName: string = 'config.json',
): boolean {
  return event.kind === 'modify' && event.paths.some((path) => path.includes(configFileName));
}

export function shouldRefreshPauseState(
  event: IWatchEventLike,
  pauseFileName: string = 'pause',
): boolean {
  return ['create', 'modify', 'remove'].includes(event.kind) &&
    event.paths.some((path) => path.includes(pauseFileName));
}

export function analyzeConfigReload(
  oldDeviceCount: number,
  newDeviceCount: number,
): IConfigReloadSnapshot {
  if (newDeviceCount > 0 && oldDeviceCount === 0) {
    return {
      transition: 'monitoringWillStart',
      message: `Configuration reloaded! Found ${newDeviceCount} UPS device(s)`,
      shouldInitializeUpsStatus: false,
      shouldLogMonitoringStart: true,
    };
  }

  if (newDeviceCount !== oldDeviceCount) {
    return {
      transition: 'deviceCountChanged',
      message: `Configuration reloaded! UPS devices: ${oldDeviceCount} -> ${newDeviceCount}`,
      shouldInitializeUpsStatus: true,
      shouldLogMonitoringStart: false,
    };
  }

  return {
    transition: 'reloaded',
    message: 'Configuration reloaded successfully',
    shouldInitializeUpsStatus: false,
    shouldLogMonitoringStart: false,
  };
}