// Build the choropleth payload from a GameState: every **sub-region id** in a
// nation's territory maps to its owning nation plus that nation's stable color
// (see shared.nationColor). The client merges this onto public/regions.geo.json
// and calls source.setData(). The map is keyed by whatever ids sit in
// `nation.territory` — sub-region ids (e.g. `FR-57`) as of v0.19 — so it needs
// no change to move from country to sub-region granularity; a sub-region in no
// nation's territory is simply absent (unowned, rendered grey by the map).
import { nationColor, type RegionMap } from '../shared/protocol';
import type { GameState } from '../shared/types';

export function buildRegionMap(state: GameState): RegionMap {
  const map: RegionMap = {};
  for (const [id, nation] of Object.entries(state.nations)) {
    const color = nationColor(id);
    for (const regionId of nation.territory) {
      map[regionId] = { color, owner: nation.name, ownerId: id };
    }
  }
  return map;
}