import { EFFECT_TYPES } from './effects.js';

function byId(list, what) {
  const map = new Map(list.map((item) => [item.id, item]));
  if (map.size !== list.length) throw new Error(`Duplicate ${what} id`);
  return map;
}

function checkEffect(owner, effect, generatorsById) {
  if (!EFFECT_TYPES.includes(effect?.type)) {
    throw new Error(`${owner}: unknown effect type "${effect?.type}"`);
  }
  if (effect.target && !generatorsById.has(effect.target)) {
    throw new Error(`${owner}: unknown generator "${effect.target}"`);
  }
}

/**
 * Bundle the static game data (public/data/*.json) with lookup tables and
 * validate it, so a typo in a JSON file fails loudly at startup (and in the
 * tests) instead of mid-game.
 */
export function buildContext({
  rules,
  generators,
  upgrades,
  research,
  legacy,
  achievements,
  investments,
  tabs,
}) {
  const generatorsById = byId(generators, 'generator');
  const upgradesById = byId(upgrades, 'upgrade');
  const researchById = byId(research, 'research');
  const perksById = byId(legacy, 'legacy perk');
  const achievementsById = byId(achievements, 'achievement');
  const societiesById = byId(investments.societies, 'society');
  byId(tabs, 'tab');

  for (const u of upgrades) {
    checkEffect(`Upgrade "${u.id}"`, u.effect, generatorsById);
    if (u.requires && !upgradesById.has(u.requires)) {
      throw new Error(`Upgrade "${u.id}": unknown requirement "${u.requires}"`);
    }
  }
  for (const node of research) {
    checkEffect(`Research "${node.id}"`, node.effect, generatorsById);
    for (const req of node.requires) {
      if (!researchById.has(req)) throw new Error(`Research "${node.id}": unknown requirement "${req}"`);
    }
  }
  for (const perk of legacy) checkEffect(`Perk "${perk.id}"`, perk.effect, generatorsById);
  for (const a of achievements) checkEffect(`Achievement "${a.id}"`, a.effect, generatorsById);
  for (const s of investments.societies) {
    if (!investments.tiers[s.tier]) throw new Error(`Society "${s.id}": unknown tier "${s.tier}"`);
  }

  return {
    rules,
    generators,
    upgrades,
    research,
    legacy,
    achievements,
    investments,
    tabs,
    generatorsById,
    upgradesById,
    researchById,
    perksById,
    achievementsById,
    societiesById,
  };
}