using Vanguard.Rules.Engine;

namespace Vanguard.Rules.Diagnostics;

/// <summary>Проверки, которые должны выполняться после любой команды.</summary>
public static class GameInvariants
{
    public const int DeckSize = 50;

    public static IReadOnlyList<string> Check(GameState state)
    {
        var issues = new List<string>();
        var ids = new HashSet<int>();

        for (var player = 0; player < 2; player++)
        {
            var p = state.Players[player];
            var zones = new List<IEnumerable<CardInstance>>
            {
                p.Deck,
                p.Hand,
                p.Soul,
                p.Damage,
                p.Drop,
                p.Trigger,
                p.Guardian,
                p.Vanguard is null ? Enumerable.Empty<CardInstance>() : new[] { p.Vanguard },
                p.RearGuards.OfType<CardInstance>(),
                state.InTransit.Where(t => t.Player == player).Select(t => t.Card),
            };

            var total = 0;
            foreach (var card in zones.SelectMany(zone => zone))
            {
                if (!ids.Add(card.Id))
                    issues.Add($"Игрок {player}: повтор instanceId {card.Id}");

                total++;
            }

            if (total != DeckSize)
                issues.Add($"Игрок {player}: {total} карт вместо {DeckSize}");

            if (p.Damage.Count > GameEngine.MaxDamage)
                issues.Add($"Игрок {player}: урон {p.Damage.Count} больше {GameEngine.MaxDamage}");
        }

        if (state.IsFinished && state.Winner is null)
            issues.Add("Партия завершена без победителя");

        return issues;
    }
}