using System.Text;
using FluentAssertions;
using Game.CardWars;
using OECS;
using Xunit;
using Xunit.Abstractions;

namespace Game.CardWars.Tests;

public class PlayLogTests
{
    private readonly ITestOutputHelper _output;

    public PlayLogTests(ITestOutputHelper output)
    {
        _output = output;
    }

    [Fact]
    public void OneRound_ThreePlayers_PlayLog()
    {
        CardEffectRegistry.ClearForTests();
        var (world, group) = GameFactory.Create(playerCount: 3, seed: 12345);
        var log = new StringBuilder();

        var players = GameUtil.FindAllEntities<Player>(world);
        var state = world.ReadSingleton<GameState>();

        LogSection(log, "=== CardWars Play Log — Round 1 ===");
        log.AppendLine($"Seed: {state.Seed}  |  Players: {state.PlayerCount}  |  Starting: P{state.StartingPlayerIndex}");
        log.AppendLine();

        // ── Initial hands ──
        LogSection(log, "── Starting Hands ──");
        for (int i = 0; i < players.Count; i++)
            log.AppendLine($"  P{i}: {DescribeHand(world, GameUtil.GetHandCards(world, players[i]))}");
        log.AppendLine();

        // ── Play Phase ──
        LogSection(log, "── Play Phase ──");
        RunPlayPhase(world, group, players, log);

        // ── Flip Phase ──
        LogSection(log, "── Flip Phase ──");
        RunFlipPhase(world, group, players, log);

        // ── Scoring (capture powers BEFORE cleanup) ──
        LogSection(log, "── Scoring ──");
        var powers = new int[players.Count];
        for (int i = 0; i < players.Count; i++)
            powers[i] = GameUtil.CalculatePower(world, players[i]);

        // Advance to scoring phase and let systems run.
        ref var mutable = ref world.GetSingleton<GameState>();
        mutable.Phase = GamePhase.Scoring;
        world.MarkModified<GameState>(World.SingletonEntity);
        group.RunLogical(); // ScoringSystem → CleanupSystem

        for (int i = 0; i < players.Count; i++)
            log.AppendLine($"  P{i} power: {powers[i]}");

        int winnerIdx = Array.IndexOf(powers, powers.Max());
        log.AppendLine($"  Winner: P{winnerIdx} (power={powers[winnerIdx]})");

        // Find the castle that was just awarded (it has HeldBy but no Castle component).
        var wonCastleEntity = world.GetSources<HeldBy>(players[winnerIdx])
            .FirstOrDefault(c => !world.HasComponent<Castle>(c) && !world.HasComponent<CardDef>(c));
        log.AppendLine($"  Castle awarded to P{winnerIdx}");
        log.AppendLine();

        // ── Cleanup already ran ──
        LogSection(log, "── After Cleanup ──");
        state = world.ReadSingleton<GameState>();
        log.AppendLine($"  Phase: {state.Phase}  |  Round: {state.RoundNumber}");
        for (int i = 0; i < players.Count; i++)
        {
            var hand = GameUtil.GetHandCards(world, players[i]);
            log.AppendLine($"  P{i} hand: {DescribeHand(world, hand)}");
        }
        log.AppendLine();

        // ── Castle counts ──
        LogSection(log, "── Castle Tally ──");
        for (int i = 0; i < players.Count; i++)
        {
            // A won castle: has HeldBy to this player, no CardDef, no Card, no Leader, no Banner.
            var castleEntities = world.GetSources<HeldBy>(players[i])
                .Where(c => !world.HasComponent<CardDef>(c)
                         && !world.HasComponent<Card>(c)
                         && !world.HasComponent<Leader>(c)
                         && !world.HasComponent<Banner>(c))
                .ToList();
            log.AppendLine($"  P{i}: {castleEntities.Count} castle(s)");
        }
        log.AppendLine();

        _output.WriteLine(log.ToString());

        state.Phase.Should().BeOneOf(GamePhase.PlayPhase, GamePhase.GameOver);
    }

    // ── Play phase: greedy agent, plays best card each turn ──

    private static void RunPlayPhase(World world, SystemGroup group, List<Entity> players, StringBuilder log)
    {
        var state = world.ReadSingleton<GameState>();
        int startIdx = state.StartingPlayerIndex;
        int current = startIdx;
        int safety = 0;

        while (safety++ < 100)
        {
            state = world.ReadSingleton<GameState>();
            if (state.Phase != GamePhase.PlayPhase) break;

            var player = players[state.CurrentPlayerIndex];
            var hand = GameUtil.GetHandCards(world, player);

            if (hand.Count > 0)
            {
                var best = PickBestCard(world, hand);
                var def = world.ReadComponent<CardDef>(best);
                int rank = def.Ranks.Max();

                world.Commands.Enqueue(new PlayCardCommand
                {
                    CardEntity = best,
                    Rank = rank,
                    FaceDown = false,
                    TargetPlayer = null
                });
                group.RunLogical();

                log.AppendLine($"  P{state.CurrentPlayerIndex} plays [{def.Name}] rank={rank}");

                // Resolve any pending choices automatically.
                ResolvePendingChoices(world, group, players, log);
            }
            else
            {
                world.Commands.Enqueue(new SkipPlayCommand());
                group.RunLogical();
                log.AppendLine($"  P{state.CurrentPlayerIndex} skips (hand empty)");
            }
        }

        state = world.ReadSingleton<GameState>();
        log.AppendLine($"  Phase → {state.Phase}");
        log.AppendLine();
    }

    // ── Flip phase ──

    private static void RunFlipPhase(World world, SystemGroup group, List<Entity> players, StringBuilder log)
    {
        var state = world.ReadSingleton<GameState>();
        if (state.Phase != GamePhase.FlipPhase)
        {
            ref var m = ref world.GetSingleton<GameState>();
            m.Phase = GamePhase.FlipPhase;
            m.CurrentPlayerIndex = m.StartingPlayerIndex;
            world.MarkModified<GameState>(World.SingletonEntity);
        }

        for (int i = 0; i < players.Count; i++)
        {
            state = world.ReadSingleton<GameState>();
            var player = players[state.CurrentPlayerIndex];
            var field = GameUtil.GetFieldCards(world, player);
            bool anyFaceDown = field.Any(c =>
                world.HasComponent<Card>(c) && world.ReadComponent<Card>(c).FaceDown);

            if (anyFaceDown)
            {
                var fd = field.First(c =>
                    world.HasComponent<Card>(c) && world.ReadComponent<Card>(c).FaceDown);
                world.Commands.Enqueue(new FlipCardCommand { CardEntity = fd });
                group.RunLogical();
                var def = world.ReadComponent<CardDef>(fd);
                log.AppendLine($"  P{state.CurrentPlayerIndex} flips [{def.Name}]");
                ResolvePendingChoices(world, group, players, log);
            }
            else
            {
                log.AppendLine($"  P{state.CurrentPlayerIndex} skips flip (no face-down)");
            }

            ref var m2 = ref world.GetSingleton<GameState>();
            m2.CurrentPlayerIndex = (m2.CurrentPlayerIndex + 1) % m2.PlayerCount;
            world.MarkModified<GameState>(World.SingletonEntity);
        }
        log.AppendLine();
    }

    // ── Pending choice auto-resolver ──

    private static void ResolvePendingChoices(World world, SystemGroup group, List<Entity> players, StringBuilder log)
    {
        while (PendingChoice.Any(world))
        {
            Entity target = PickDefaultTarget(world, players);
            world.Commands.Enqueue(new ResolveChoiceCommand { Target = target });
            group.RunLogical();
            log.AppendLine($"    ↳ auto-resolve → {DescribeEntity(world, target)}");
        }
    }

    private static Entity PickDefaultTarget(World world, List<Entity> players)
    {
        if (world.HasSingleton<PendingMercenary>())
        {
            var p = world.ReadSingleton<PendingMercenary>();
            return GameUtil.GetFieldCards(world, p.Player)
                .FirstOrDefault(c => world.HasComponent<Card>(c) && world.ReadComponent<Card>(c).Rank > 0);
        }
        if (world.HasSingleton<PendingDancer>())
        {
            var p = world.ReadSingleton<PendingDancer>();
            return GameUtil.GetFieldCards(world, p.Player)
                .FirstOrDefault(c => world.HasComponent<Card>(c) && world.ReadComponent<Card>(c).Rank > 0);
        }
        if (world.HasSingleton<PendingPaladin>())
        {
            var p = world.ReadSingleton<PendingPaladin>();
            var powered = GameUtil.GetFieldCards(world, p.Player)
                .FirstOrDefault(c => world.HasComponent<Card>(c) && world.ReadComponent<Card>(c).Rank > 0);
            return powered != Entity.Null ? powered : CardEffectHelpers.GetBanner(world, p.Player);
        }
        if (world.HasSingleton<PendingNun>())
        {
            var p = world.ReadSingleton<PendingNun>();
            return GameUtil.GetFieldCards(world, p.Player).FirstOrDefault();
        }
        if (world.HasSingleton<PendingScout>())
        {
            var p = world.ReadSingleton<PendingScout>();
            return players.FirstOrDefault(pl => pl != p.Player);
        }
        if (world.HasSingleton<PendingPegasus>())
        {
            var p = world.ReadSingleton<PendingPegasus>();
            return GameUtil.GetFieldCards(world, p.Player).FirstOrDefault(c => c != p.CardEntity);
        }
        if (world.HasSingleton<PendingCurseMaster>())
        {
            return GameUtil.FindAllEntities<Horn>(world).FirstOrDefault();
        }
        return Entity.Null;
    }

    // ── Helpers ──

    private static Entity PickBestCard(World world, List<Entity> hand)
    {
        Entity best = Entity.Null;
        int bestRank = -999;
        foreach (var c in hand)
        {
            int maxRank = world.ReadComponent<CardDef>(c).Ranks.Max();
            if (maxRank > bestRank) { bestRank = maxRank; best = c; }
        }
        return best;
    }

    private static string DescribeHand(World world, List<Entity> hand)
    {
        var cards = hand.Where(c => world.HasComponent<CardDef>(c)).ToList();
        if (cards.Count == 0) return "(empty)";
        return string.Join("  ", cards.Select(c =>
        {
            var def = world.ReadComponent<CardDef>(c);
            return $"[{def.Name} {string.Join("/", def.Ranks)}]";
        }));
    }

    private static string DescribeEntity(World world, Entity e)
    {
        if (e == Entity.Null) return "(none)";
        if (world.HasComponent<CardDef>(e)) return $"[{world.ReadComponent<CardDef>(e).Name}]";
        if (world.HasComponent<Player>(e)) return $"P{world.ReadComponent<Player>(e).Index}";
        if (world.HasComponent<Horn>(e)) return "[Horn token]";
        if (world.HasComponent<Skull>(e)) return "[Skull token]";
        if (world.HasComponent<Banner>(e)) return "[Banner]";
        return e.ToString();
    }

    private static void LogSection(StringBuilder log, string title) => log.AppendLine(title);
}