using FluentAssertions;
using Game.CardWars;
using OECS;
using Xunit;

namespace Game.CardWars.Tests;

public class GameSetupTests
{
    private static (World World, SystemGroup Group) Setup()
    {
        // Reset registry state between tests.
        CardEffectRegistry.ClearForTests();
        return GameFactory.Create(playerCount: 2, seed: 42);
    }

    [Fact]
    public void CreateGame_CreatesPlayersAndDecks()
    {
        var (world, _) = Setup();

        var state = world.ReadSingleton<GameState>();
        state.Phase.Should().Be(GamePhase.PlayPhase);
        state.PlayerCount.Should().Be(2);
        state.RoundNumber.Should().Be(1);

        GameUtil.FindEntity<PublicDeck>(world).Should().NotBe(Entity.Null);
        GameUtil.FindAllEntities<Player>(world).Should().HaveCount(2);
        GameUtil.FindAllEntities<Leader>(world).Should().HaveCount(2);
        GameUtil.FindAllEntities<Banner>(world).Should().HaveCount(2);
        GameUtil.FindAllEntities<Castle>(world).Should().NotBeEmpty();
    }

    [Fact]
    public void StartingHand_HasThreeCards()
    {
        var (world, _) = Setup();

        foreach (var player in GameUtil.FindAllEntities<Player>(world))
        {
            var hand = GameUtil.GetHandCards(world, player);
            hand.Should().HaveCount(3);
        }
    }

    [Fact]
    public void PlayCard_MovesCardFromHandToField()
    {
        var (world, group) = Setup();

        var state = world.ReadSingleton<GameState>();
        var player = PlayCardCommand.FindPlayerByIndex(world, state.CurrentPlayerIndex);

        var hand = GameUtil.GetHandCards(world, player);
        var cardInHand = hand[0];
        var def = world.ReadComponent<CardDef>(cardInHand);

        world.Commands.Enqueue(new PlayCardCommand
        {
            CardEntity = cardInHand,
            Rank = def.Ranks[0],
            FaceDown = false,
            TargetPlayer = null
        });
        group.RunLogical();

        GameUtil.GetFieldCards(world, player).Should().Contain(cardInHand);
        var cardData = world.ReadComponent<Card>(cardInHand);
        cardData.Rank.Should().Be(def.Ranks[0]);
        cardData.FaceDown.Should().BeFalse();
    }

    [Fact]
    public void PlayCardFaceDown_CardIsHidden()
    {
        var (world, group) = Setup();

        var state = world.ReadSingleton<GameState>();
        var player = PlayCardCommand.FindPlayerByIndex(world, state.CurrentPlayerIndex);

        var hand = GameUtil.GetHandCards(world, player);
        var cardInHand = hand[0];
        var def = world.ReadComponent<CardDef>(cardInHand);

        world.Commands.Enqueue(new PlayCardCommand
        {
            CardEntity = cardInHand,
            Rank = def.Ranks[0],
            FaceDown = true,
            TargetPlayer = null
        });
        group.RunLogical();

        world.ReadComponent<Card>(cardInHand).FaceDown.Should().BeTrue();
    }

    [Fact]
    public void FlipCard_RevealsFaceDownCard()
    {
        var (world, group) = Setup();

        var state = world.ReadSingleton<GameState>();
        var player = PlayCardCommand.FindPlayerByIndex(world, state.CurrentPlayerIndex);

        var hand = GameUtil.GetHandCards(world, player);
        var cardInHand = hand[0];
        var def = world.ReadComponent<CardDef>(cardInHand);

        // Play face-down.
        world.Commands.Enqueue(new PlayCardCommand
        {
            CardEntity = cardInHand,
            Rank = def.Ranks[0],
            FaceDown = true,
            TargetPlayer = null
        });
        group.RunLogical();

        // Advance to flip phase: both players skip.
        world.Commands.Enqueue(new SkipPlayCommand());
        group.RunLogical();
        world.Commands.Enqueue(new SkipPlayCommand());
        group.RunLogical();

        world.ReadSingleton<GameState>().Phase.Should().Be(GamePhase.FlipPhase);

        // Flip it.
        world.Commands.Enqueue(new FlipCardCommand { CardEntity = cardInHand });
        group.RunLogical();

        world.ReadComponent<Card>(cardInHand).FaceDown.Should().BeFalse();
    }

    [Fact]
    public void SkipPlay_AdvancesTurn()
    {
        var (world, group) = Setup();

        var state = world.ReadSingleton<GameState>();
        int originalPlayer = state.CurrentPlayerIndex;

        world.Commands.Enqueue(new SkipPlayCommand());
        group.RunLogical();

        state = world.ReadSingleton<GameState>();
        state.CurrentPlayerIndex.Should().Be((originalPlayer + 1) % 2);
    }
}