using Game.Blackjack;
using OECS;
using System.Text;

namespace Game.Blackjack.Tests;

internal static class TestHelpers
{
    private const int StartingChips = 100;

    /// <summary>
    /// Creates a fresh Blackjack world with systems registered and GameState singleton initialized.
    /// </summary>
    public static (World World, SystemGroup Group) SetupGame(uint seed = 42)
    {
        var world = new World();
        var group = new SystemGroup(world);
        group.Add(new DeckSetupSystem());
        group.Add(new DealSystem());
        group.Add(new PlayerBustCheckSystem());
        group.Add(new DealerSystem());

        world.SetSingleton(new GameState
        {
            Phase = GamePhase.Betting,
            Result = RoundResult.None,
            Chips = StartingChips,
            CurrentBet = 0,
            RoundNumber = 1,
            Seed = seed
        });
        world.PostChanges();

        return (world, group);
    }

    /// <summary>
    /// Returns a human-readable textual snapshot of the world state.
    /// </summary>
    public static string SnapshotWorld(World world)
    {
        var sb = new StringBuilder();
        var state = world.ReadSingleton<GameState>();
        sb.AppendLine($"Phase: {state.Phase}");
        sb.AppendLine($"Chips: {state.Chips}");
        sb.AppendLine($"Bet: {state.CurrentBet}");
        sb.AppendLine($"Round: {state.RoundNumber}");
        sb.AppendLine($"Result: {state.Result}");
        sb.AppendLine($"Seed: {state.Seed}");

        var deckEntity = FindEntity<Deck>(world);
        if (deckEntity != Entity.Null)
        {
            var cardsInDeck = world.GetSources<InDeck>(deckEntity).ToList();
            sb.AppendLine($"Cards in deck: {cardsInDeck.Count}");
        }

        var playerHand = FindEntity<PlayerHand>(world);
        if (playerHand != Entity.Null)
        {
            var cards = world.GetSources<Holds>(playerHand).ToList();
            sb.AppendLine($"Player hand: {cards.Count} cards");
            foreach (var cardEntity in cards)
            {
                var card = world.ReadComponent<Card>(cardEntity);
                sb.AppendLine($"  {card.Rank} of {card.Suit}");
            }
        }

        var dealerHand = FindEntity<DealerHand>(world);
        if (dealerHand != Entity.Null)
        {
            var cards = world.GetSources<Holds>(dealerHand).ToList();
            sb.AppendLine($"Dealer hand: {cards.Count} cards");
            foreach (var cardEntity in cards)
            {
                var card = world.ReadComponent<Card>(cardEntity);
                sb.AppendLine($"  {card.Rank} of {card.Suit}");
            }
        }

        int entityCount = 0;
        using (var iter = world.Select<Card>())
        {
            while (iter.MoveNext()) entityCount++;
        }
        sb.AppendLine($"Card entities: {entityCount}");

        return sb.ToString().TrimEnd();
    }

    public static Entity FindEntity<T>(World world) where T : struct
    {
        return world.FindEntity<T>();
    }

    public static int CountCardsInHand(World world, Entity handEntity)
    {
        return world.GetSources<Holds>(handEntity).Count;
    }

    public static List<string> GetHandCards(World world, Entity hand)
    {
        var cards = new List<string>();
        foreach (var cardEntity in world.GetSources<Holds>(hand))
        {
            var card = world.ReadComponent<Card>(cardEntity);
            cards.Add($"{card.Rank} of {card.Suit}");
        }
        return cards;
    }

    public static List<(Suit, Rank)> GetAllCards(World world)
    {
        var cards = new List<(Suit, Rank)>();
        using (var iter = world.Select<Card>())
        {
            while (iter.MoveNext())
            {
                var card = iter.Val1;
                cards.Add((card.Suit, card.Rank));
            }
        }
        cards.Sort((a, b) =>
        {
            int cmp = a.Item1.CompareTo(b.Item1);
            return cmp != 0 ? cmp : a.Item2.CompareTo(b.Item2);
        });
        return cards;
    }
}