import { describe, expect, it } from 'vitest';
import { deserializeState, serializeState } from '@core/rules/GameState';
import { apply, createGame, currentActor, legalActions } from '@core/rules/DurakRules';

describe('state serialization', () => {
    it('round-trips a fresh game through JSON', () => {
        const { state } = createGame({ players: ['you', 'bot'], seed: 4242 });
        const restored = deserializeState(JSON.parse(JSON.stringify(serializeState(state))));
        expect(serializeState(restored)).toEqual(serializeState(state));
    });

    it('round-trips a game in the middle of a turn', () => {
        let { state } = createGame({ players: ['you', 'bot'], seed: 99 });
        for (let i = 0; i < 5; i++) {
            const actor = currentActor(state);
            if (!actor) break;
            state = apply(state, legalActions(state, actor)[0]).state;
        }

        const restored = deserializeState(JSON.parse(JSON.stringify(serializeState(state))));
        expect(serializeState(restored)).toEqual(serializeState(state));
        expect(currentActor(restored)).toBe(currentActor(state));
    });

    it('restores cards as the same flyweight instances', () => {
        const { state } = createGame({ players: ['you', 'bot'], seed: 7 });
        const restored = deserializeState(serializeState(state));
        expect(restored.players[0].hand[0]).toBe(state.players[0].hand[0]);
        expect(restored.trumpCard).toBe(state.trumpCard);
    });

    it('replays identically from a restored state', () => {
        const { state } = createGame({ players: ['you', 'bot'], seed: 2001 });
        const restored = deserializeState(serializeState(state));

        // The same action object works on both, because cards are flyweights and
        // an action carries no reference to the state it was generated from.
        const actor = currentActor(state) as string;
        const action = legalActions(state, actor)[0];

        expect(serializeState(apply(restored, action).state))
            .toEqual(serializeState(apply(state, action).state));
    });
});