import type { ComponentId, LevelId, Trend } from './types';

/** Pressure scale — mirrors packages/config/pressure.yaml (ids/max) and the design palette (colours). */
export const LEVELS: { id: LevelId; max: number; label: string; short: string; color: string }[] = [
  { id: 'calm', max: 10, label: 'Exceptionally calm', short: 'Calm', color: '#4CC9F0' },
  { id: 'normal', max: 25, label: 'Normal', short: 'Normal', color: '#7FB77E' },
  { id: 'elevated', max: 40, label: 'Elevated', short: 'Elevated', color: '#E9C46A' },
  { id: 'stressed', max: 55, label: 'Stressed', short: 'Stressed', color: '#F4A261' },
  { id: 'high', max: 70, label: 'Highly stressed', short: 'High', color: '#E76F51' },
  { id: 'severe', max: 85, label: 'Severe disruption', short: 'Severe', color: '#D62828' },
  { id: 'extreme', max: 100, label: 'Extreme Internet event', short: 'Extreme', color: '#F72585' },
];

export const NEUTRAL = '#0F151D';
export const ACCENT = '#5B8DEF';

export function levelFor(value: number | null | undefined): (typeof LEVELS)[number] {
  if (value == null || Number.isNaN(value)) return LEVELS[1]!;
  return LEVELS.find((l) => value <= l.max) ?? LEVELS[LEVELS.length - 1]!;
}

export function levelById(id: LevelId | string | null | undefined) {
  return LEVELS.find((l) => l.id === id);
}

/** Colour for a level id or a numeric pressure value. */
export function pressureColor(levelOrValue: LevelId | number | null | undefined): string {
  if (levelOrValue == null) return '#3A4756';
  if (typeof levelOrValue === 'number') return levelFor(levelOrValue).color;
  return levelById(levelOrValue)?.color ?? '#3A4756';
}

export function levelWord(levelOrValue: LevelId | number | null | undefined): string {
  if (levelOrValue == null) return '—';
  const l = typeof levelOrValue === 'number' ? levelFor(levelOrValue) : levelById(levelOrValue);
  return (l?.short ?? '—').toUpperCase();
}

export const COMPONENT_ORDER: ComponentId[] = ['routing', 'latency', 'dns', 'availability', 'http_tls', 'path', 'corroboration'];
export const COMPONENT_LABEL: Record<ComponentId, string> = {
  routing: 'Routing',
  latency: 'Latency',
  dns: 'DNS',
  availability: 'Availability',
  http_tls: 'HTTP/TLS',
  path: 'Path',
  corroboration: 'Corroboration',
};

export function trendArrow(trend: Trend | undefined, delta?: number): string {
  if (trend === 'rising' || (trend === undefined && (delta ?? 0) > 0)) return '↑';
  if (trend === 'falling' || (trend === undefined && (delta ?? 0) < 0)) return '↓';
  return '→';
}

export const STATUS_COLOR: Record<string, string> = {
  detected: '#E9C46A',
  developing: '#F4A261',
  active: '#E76F51',
  recovering: '#4CC9F0',
  resolved: '#8B98A5',
  online: '#7FB77E',
  stale: '#E9C46A',
  offline: '#D62828',
  excluded: '#8B98A5',
};