import type { TopicId } from './types';

/**
 * Static mirror of `registry/topics.yaml` (id, name, short, order, blurb). The API is the source of truth for
 * indicator membership and counts; this list exists so navigation, the home grid and metadata never need a
 * fetch. Keep in sync when the registry changes (19 topics, fixed set — ARCHITECTURE §4).
 */
export interface TopicDef {
  id: TopicId;
  name: string;
  short: string;
  order: number;
  blurb: string;
}

export const TOPICS: readonly TopicDef[] = [
  { id: 'economy', name: 'Economy', short: 'Economy', order: 1, blurb: 'Output, growth, prices, productivity and external balance.' },
  { id: 'government', name: 'Government & public finance', short: 'Government', order: 2, blurb: 'Public debt, deficits, revenue, spending and taxation.' },
  { id: 'population', name: 'Population & demographics', short: 'Population', order: 3, blurb: 'Size, growth, ages, births, deaths, urbanisation and migration.' },
  { id: 'labor', name: 'Employment & wages', short: 'Labor', order: 4, blurb: 'Unemployment, participation, employment, youth, wages and hours.' },
  { id: 'income', name: 'Income & inequality', short: 'Income', order: 5, blurb: 'Living standards, poverty and distribution.' },
  { id: 'housing', name: 'Housing', short: 'Housing', order: 6, blurb: 'Prices, rents, affordability, mortgages and construction.' },
  { id: 'health', name: 'Health', short: 'Health', order: 7, blurb: 'Longevity, mortality, health system capacity and risk factors.' },
  { id: 'education', name: 'Education', short: 'Education', order: 8, blurb: 'Literacy, enrolment, attainment and spending.' },
  { id: 'trade', name: 'Trade', short: 'Trade', order: 9, blurb: 'Exports, imports, balances, openness and composition.' },
  { id: 'energy', name: 'Energy', short: 'Energy', order: 10, blurb: 'Generation, consumption, mix, dependence and intensity.' },
  { id: 'climate', name: 'Climate', short: 'Climate', order: 11, blurb: 'Greenhouse gases, intensity and temperature contribution.' },
  { id: 'environment', name: 'Environment', short: 'Environment', order: 12, blurb: 'Forests, air quality, land, water and protected areas.' },
  { id: 'infrastructure', name: 'Infrastructure & transportation', short: 'Infrastructure', order: 13, blurb: 'Transport networks, passengers, freight and access.' },
  { id: 'digital', name: 'Digital economy & Internet', short: 'Digital', order: 14, blurb: 'Connectivity, adoption and digital infrastructure.' },
  { id: 'innovation', name: 'Innovation, research & technology', short: 'Innovation', order: 15, blurb: 'R&D, patents, publications, researchers and high-tech.' },
  { id: 'agriculture', name: 'Agriculture & natural resources', short: 'Agriculture', order: 16, blurb: 'Land, production, employment and resource rents.' },
  { id: 'tourism', name: 'Tourism', short: 'Tourism', order: 17, blurb: 'Arrivals, departures and tourism receipts.' },
  { id: 'security', name: 'Security & governance', short: 'Security', order: 18, blurb: 'Homicide, military spending, refugees, displacement and institutions.' },
  { id: 'quality-of-life', name: 'Quality of life', short: 'Quality of life', order: 19, blurb: 'Human development, happiness, safety, access and environment.' },
];

const BY_ID = new Map(TOPICS.map((tp) => [tp.id, tp]));
export function topicById(id: string): TopicDef | undefined {
  return BY_ID.get(id as TopicId);
}
export function isTopicId(id: string): id is TopicId {
  return BY_ID.has(id as TopicId);
}

/** Headline indicators on the country overview, in order (registry/topics.yaml `headline`). */
export const HEADLINE_INDICATORS = [
  'population',
  'gdp',
  'gdp-per-capita',
  'gdp-growth',
  'inflation',
  'unemployment-rate',
  'life-expectancy',
  'median-age',
  'general-government-gross-debt-pct-gdp',
  'co2-per-capita',
  'renewable-electricity-share',
  'internet-users',
] as const;

/** Indicator slug → topic id fallback (used to build `/countries/[slug]/[topic]#indicator` links for headline metrics). */
export const HEADLINE_TOPIC: Record<(typeof HEADLINE_INDICATORS)[number], TopicId> = {
  population: 'population',
  gdp: 'economy',
  'gdp-per-capita': 'economy',
  'gdp-growth': 'economy',
  inflation: 'economy',
  'unemployment-rate': 'labor',
  'life-expectancy': 'health',
  'median-age': 'population',
  'general-government-gross-debt-pct-gdp': 'government',
  'co2-per-capita': 'climate',
  'renewable-electricity-share': 'energy',
  'internet-users': 'digital',
};