import { describe, it, expect } from 'vitest';
import { readFileSync } from 'node:fs';
import { applyEndAdjustment, winner, type EndReason } from './engine';
import { RULESETS } from './ruleset';
import type { Variant } from '../model';

// The offline engine must settle unplayed racks and decide the winner exactly as the Go engine
// does, so a local game finishes with the same scores. Golden from the in-package emitter
// (backend/internal/engine/endfixture_test.go).
interface EndCase {
  name: string;
  variant: Variant;
  reason: EndReason;
  hands: number[][];
  scores: number[];
  resigned: boolean[];
  toMove: number;
  scoresAfter: number[];
  winner: number;
}

const fx = JSON.parse(
  readFileSync(new URL('./testdata/endgame.json', import.meta.url), 'utf8'),
) as { cases: EndCase[] };

describe('offline engine end-game parity vs Go', () => {
  for (const c of fx.cases) {
    it(c.name, () => {
      const values = RULESETS[c.variant].values;
      const after = applyEndAdjustment(c.reason, c.hands, c.scores, c.toMove, values);
      expect(after).toEqual(c.scoresAfter);
      expect(winner(true, c.reason, after, c.resigned)).toBe(c.winner);
    });
  }
});