import { config } from '../config/Config.js';

/**
 * Formats a generated system into a readable "dossier" for UI.
 *
 * Pure — no Phaser — so it's testable in Node and reusable anywhere a
 * system needs describing (the HUD today; the star map, tooltips, saves,
 * or a terminal UI later). Scenes stay thin: they render what this
 * returns.
 *
 * The dossier is deliberately compact — the per-settlement and gate
 * detail lives elsewhere (star chart, map, the content itself). What it
 * carries: identity (type + star class), who controls the system, and
 * how many are settled here.
 *
 *   const report = formatSystemReport(content);
 *   // { title, subtitle, faction, population, status, statusColor }
 *   //   title      — the system name
 *   //   subtitle   — "Main Sequence system · star G"
 *   //   status     — "Faction: Neutral · Pop ~1.2M" (or "… · Unclaimed")
 */
export function formatSystemReport(content, typeDefs = null) {
  const types = typeDefs ?? config.get('systems.types', {});
  const typeDef = types[content.type] ?? {};

  const population = (content.settlements ?? []).reduce(
    (sum, s) => sum + (s.population ?? 0),
    0,
  );

  // Faction control — every system is Neutral for now. When factions
  // land (the `owner` seam on settlements), this is where the faction's
  // name + theme color will plug in (Neutral = light gray).
  const faction = 'Neutral';
  const statusColor = '#c4cad8';

  return {
    title: content.name,
    subtitle: `${typeDef.label ?? content.type} system · star ${content.star.class}`,
    faction,
    population,
    status:
      population > 0
        ? `Faction: ${faction} · Pop ~${formatPop(population)}`
        : `Faction: ${faction} · Unclaimed`,
    statusColor,
  };
}

/** 1234 → "1.2k", 9000000 → "9.0M" */
export function formatPop(n) {
  if (n >= 1e6) return `${(n / 1e6).toFixed(1)}M`;
  if (n >= 1e3) return `${(n / 1e3).toFixed(1)}k`;
  return String(n);
}