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.
 *
 *   const report = formatSystemReport(content);
 *   // { title, subtitle, settlements: [{ text, color, population }],
 *   //   summary, population }
 */
export function formatSystemReport(content, typeDefs = null, kindDefs = null) {
  const types = typeDefs ?? config.get('systems.types', {});
  const kinds = kindDefs ?? config.get('settlements.kinds', {});
  const typeDef = types[content.type] ?? {};

  const planetName = (ordinal) => {
    const p = content.planets.find((pl) => pl.ordinal === ordinal);
    return p ? p.name : `planet ${ordinal}`;
  };

  const settlements = [];
  for (const s of content.settlements ?? []) {
    const def = kinds[s.kind] ?? {};
    const where =
      s.anchor?.type === 'planet' ? `on ${planetName(s.anchor.ordinal)}` : 'in open space';
    settlements.push({
      text: `${s.name}  ·  ${def.label ?? s.kind} ${where}`,
      color: def.theme?.color ?? '#8fa0c9',
      population: s.population ?? 0,
    });
  }

  const population = settlements.reduce((sum, s) => sum + s.population, 0);
  const n = settlements.length;
  const summary =
    n === 0
      ? 'charted · unclaimed'
      : `${n} settlement${n === 1 ? '' : 's'} · pop ~${formatPop(population)}`;

  const planetN = content.planets.length;
  return {
    title: content.name,
    subtitle: `${typeDef.label ?? content.type} system · star ${content.star.class} · ${planetN} planet${planetN === 1 ? '' : 's'}`,
    settlements,
    summary,
    population,
  };
}

/** 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);
}