/**
 * Tempo Mode engine — Phase D.3.
 *
 * Adjusts timer urgency and cascade presets based on the user's current
 * energy/focus level. Pure TS, no React.
 */

export type TempoLevel = 'deep_focus' | 'normal' | 'low_energy' | 'winding_down';

export interface TempoConfig {
  level: TempoLevel;
  label: string;
  description: string;
  urgencyOverride: string;
  cascadeOverride: string;
  notificationMute: boolean;
}

export const TEMPO_CONFIGS: Record<TempoLevel, TempoConfig> = {
  deep_focus: {
    level: 'deep_focus',
    label: 'Deep Focus',
    description: 'Minimal interruptions. Only critical timers fire.',
    urgencyOverride: 'passive',
    cascadeOverride: 'minimal',
    notificationMute: true,
  },
  normal: {
    level: 'normal',
    label: 'Normal',
    description: 'Standard timer behavior.',
    urgencyOverride: 'standard',
    cascadeOverride: 'standard',
    notificationMute: false,
  },
  low_energy: {
    level: 'low_energy',
    label: 'Low Energy',
    description: 'Gentler reminders. Extended snooze times.',
    urgencyOverride: 'gentle',
    cascadeOverride: 'minimal',
    notificationMute: false,
  },
  winding_down: {
    level: 'winding_down',
    label: 'Winding Down',
    description: 'Quiet mode. Non-critical timers deferred.',
    urgencyOverride: 'passive',
    cascadeOverride: 'minimal',
    notificationMute: true,
  },
};

/**
 * Compute effective urgency based on tempo mode.
 */
export function getEffectiveUrgency(
  timerUrgency: string,
  tempoLevel: TempoLevel,
): string {
  if (tempoLevel === 'normal') return timerUrgency;

  // Critical timers always fire regardless of tempo
  if (timerUrgency === 'critical') return 'critical';

  // In deep_focus or winding_down, downgrade non-critical to passive
  if (tempoLevel === 'deep_focus' || tempoLevel === 'winding_down') {
    return timerUrgency === 'important' ? 'standard' : 'passive';
  }

  // low_energy: make everything gentler
  if (tempoLevel === 'low_energy') {
    if (timerUrgency === 'important') return 'standard';
    if (timerUrgency === 'standard') return 'gentle';
    return 'passive';
  }

  return timerUrgency;
}

/**
 * Compute effective cascade preset based on tempo mode.
 */
export function getEffectiveCascade(
  cascadePreset: string,
  tempoLevel: TempoLevel,
): string {
  if (tempoLevel === 'normal') return cascadePreset;
  return TEMPO_CONFIGS[tempoLevel].cascadeOverride;
}

/**
 * Check if notifications should be muted for this tempo level.
 */
export function shouldMuteNotifications(tempoLevel: TempoLevel): boolean {
  return TEMPO_CONFIGS[tempoLevel].notificationMute;
}