export type SignalTone = 'healthy' | 'attention' | 'critical' | 'stale' | 'unknown';

export type SignalSource = {
  state?: string;
  freshness?: string;
};

export type SignalContainer = {
  state?: string;
  health?: string;
  intentionalStop?: boolean;
};

export const signalToneRank: Record<SignalTone, number> = {
  critical: 0,
  attention: 1,
  stale: 2,
  unknown: 3,
  healthy: 4,
};

export function signalToneFromState(state: string | undefined): SignalTone {
  const normalized = state?.trim().toLowerCase();
  if (normalized === 'critical' || normalized === 'faulted' || normalized === 'down' || normalized === 'failed' || normalized === 'error') return 'critical';
  if (normalized === 'attention' || normalized === 'degraded' || normalized === 'warning' || normalized === 'restarting' || normalized === 'paused' || normalized === 'removing') return 'attention';
  if (normalized === 'stale') return 'stale';
  if (normalized === 'healthy' || normalized === 'normal' || normalized === 'up' || normalized === 'running' || normalized === 'fresh') return 'healthy';
  return 'unknown';
}

export function worstSignalTone(tones: SignalTone[]): SignalTone {
  if (tones.length === 0) return 'unknown';
  return tones.reduce<SignalTone>((worst, tone) => signalToneRank[tone] < signalToneRank[worst] ? tone : worst, 'healthy');
}

/** A successful HTTP response is not healthy when its provenance is stale or unknown. */
export function sourceSignalTone(source: SignalSource | undefined): SignalTone {
  if (!source) return 'unknown';
  const freshness = source.freshness?.trim().toLowerCase();
  if (freshness === 'stale') return 'stale';
  if (freshness !== 'fresh') return 'unknown';
  return signalToneFromState(source.state);
}

/** Mirrors the backend application-state projection without treating an intentional stop as a failure. */
export function containerSignalTone(container: SignalContainer): SignalTone {
  const state = container.state?.trim().toLowerCase();
  const health = container.health?.trim().toLowerCase();
  if (state === 'running') {
    if (health === 'healthy') return 'healthy';
    if (health === 'unhealthy') return 'attention';
    return 'unknown';
  }
  if (state === 'restarting' || state === 'paused' || state === 'removing') return 'attention';
  if (state === 'exited' || state === 'dead' || state === 'stopped') return container.intentionalStop ? 'unknown' : 'critical';
  return 'unknown';
}