using Godot;
using System;
using System.Collections.Generic;
using System.Linq;
using Chessistics.Engine.Events;
using Chessistics.Engine.Model;
using Chessistics.Scripts.Board;
using Chessistics.Scripts.Pieces;
using Chessistics.Scripts.UI;

namespace Chessistics.Scripts.Presentation;

public partial class EventAnimator : Node
{
    private BoardView _boardView = null!;
    private ObjectivePanel _objectivePanel = null!;
    private ControlBar _controlBar = null!;
    private MetricsOverlay _metricsOverlay = null!;

    private readonly Dictionary<int, PieceView> _pieceViews = new();
    private readonly Dictionary<int, TrajectView> _trajectViews = new();

    private bool _animating;
    public bool IsAnimating => _animating;

    private static readonly Color WoodCargoColor = new("#A67C32");
    private static readonly Color StoneCargoColor = new("#7A7A7A");
    private static readonly Color ToolsCargoColor = new("#C87533");
    private static readonly Color ArmsCargoColor = new("#8B0000");
    private static readonly Color GoldCargoColor = new("#FFD700");

    private const float ProduceDuration = 0.35f;
    private const float TransferDuration = 0.28f;
    private const float MoveDuration = 0.32f;
    private const float KnightMoveDuration = 0.42f;
    private const float DestroyDuration = 0.45f;

    [Signal]
    public delegate void TurnAnimationCompletedEventHandler();
    [Signal]
    public delegate void VictoryReachedEventHandler();
    [Signal]
    public delegate void MissionAdvancedEventHandler();
    [Signal]
    public delegate void CollisionOccurredEventHandler(int col, int row, string victimKind, int destroyerId);

    public void Initialize(BoardView boardView, ObjectivePanel objectivePanel,
        ControlBar controlBar, MetricsOverlay metricsOverlay)
    {
        _boardView = boardView;
        _objectivePanel = objectivePanel;
        _controlBar = controlBar;
        _metricsOverlay = metricsOverlay;
    }

    public void RegisterPiece(int pieceId, PieceView pieceView, TrajectView trajectView)
    {
        _pieceViews[pieceId] = pieceView;
        _trajectViews[pieceId] = trajectView;
    }

    public void UnregisterPiece(int pieceId)
    {
        if (_pieceViews.TryGetValue(pieceId, out var pv))
        {
            pv.QueueFree();
            _pieceViews.Remove(pieceId);
        }
        if (_trajectViews.TryGetValue(pieceId, out var tv))
        {
            tv.QueueFree();
            _trajectViews.Remove(pieceId);
        }
    }

    public void ProcessEvents(IReadOnlyList<IWorldEvent> events)
    {
        _animating = true;
        var tween = CreateTween();
        tween.SetParallel(false);

        var produceEvents = new List<CargoProducedEvent>();
        var transformerEvents = new List<CargoConvertedEvent>();
        var transferEvents = new List<IWorldEvent>();
        var moveEvents = new List<PieceMovedEvent>();
        var collisionEvents = new List<PieceReturnedToStockEvent>();

        // Pre-scan: if MissionStartedEvent follows MissionCompleteEvent, it's an auto-advance (not last mission)
        bool hasAutoAdvance = events.Any(e => e is MissionStartedEvent);

        foreach (var evt in events)
        {
            switch (evt)
            {
                case TurnStartedEvent ts:
                    FlushPhases(tween, produceEvents, transformerEvents, transferEvents, moveEvents, collisionEvents);
                    tween.TweenCallback(Callable.From(() => _controlBar.UpdateTurn(ts.TurnNumber)));
                    break;

                case CargoProducedEvent produced:
                    produceEvents.Add(produced);
                    break;

                case CargoConvertedEvent converted:
                    transformerEvents.Add(converted);
                    break;

                case CargoTransferredEvent:
                case DemandProgressEvent:
                    transferEvents.Add(evt);
                    break;

                case PieceMovedEvent moved:
                    moveEvents.Add(moved);
                    break;

                case PieceReturnedToStockEvent returned:
                    collisionEvents.Add(returned);
                    break;

                case MissionCompleteEvent:
                    FlushPhases(tween, produceEvents, transformerEvents, transferEvents, moveEvents, collisionEvents);
                    tween.TweenCallback(Callable.From(() =>
                    {
                        SfxManager.Instance?.PlayVictory();
                        SpawnConfetti();
                        if (!hasAutoAdvance)
                            EmitSignal(SignalName.VictoryReached);
                    }));
                    break;

                case MissionStartedEvent:
                    FlushPhases(tween, produceEvents, transformerEvents, transferEvents, moveEvents, collisionEvents);
                    tween.TweenCallback(Callable.From(() =>
                    {
                        EmitSignal(SignalName.MissionAdvanced);
                    }));
                    break;

                case SimulationPausedEvent:
                    // Auto-pause from collision — handled by FlushPhases
                    break;

                case TurnEndedEvent:
                    FlushPhases(tween, produceEvents, transformerEvents, transferEvents, moveEvents, collisionEvents);
                    break;

                default:
                    break;
            }
        }

        FlushPhases(tween, produceEvents, transformerEvents, transferEvents, moveEvents, collisionEvents);

        tween.TweenCallback(Callable.From(() =>
        {
            _animating = false;
            EmitSignal(SignalName.TurnAnimationCompleted);
        }));
    }

    private void FlushPhases(
        Tween tween,
        List<CargoProducedEvent> produceEvents,
        List<CargoConvertedEvent> transformerEvents,
        List<IWorldEvent> transferEvents,
        List<PieceMovedEvent> moveEvents,
        List<PieceReturnedToStockEvent> collisionEvents)
    {
        // Phase 1a: Transformer conversions — copper flash, distinct from production
        if (transformerEvents.Count > 0)
        {
            var captured = transformerEvents.ToList();
            tween.TweenCallback(Callable.From(() =>
            {
                SfxManager.Instance?.PlayProduce();
                foreach (var evt in captured)
                {
                    var cell = _boardView.GetCellView(evt.TransformerCell);
                    cell?.FlashTransform(0.45f);
                    SpawnProduceParticles(evt.TransformerCell, evt.OutputCargo);
                }
            }));
            tween.TweenInterval(0.45f);
            transformerEvents.Clear();
        }

        // Phase 1: Produce — warm golden flash + particle burst
        if (produceEvents.Count > 0)
        {
            var captured = produceEvents.ToList();
            tween.TweenCallback(Callable.From(() =>
            {
                SfxManager.Instance?.PlayProduce();
                foreach (var evt in captured)
                {
                    var cell = _boardView.GetCellView(evt.ProductionCell);
                    cell?.FlashProduce(ProduceDuration);
                    SpawnProduceParticles(evt.ProductionCell, evt.Type);
                }
            }));
            tween.TweenInterval(ProduceDuration);
            produceEvents.Clear();
        }

        // Phase 2: Transfers — cargo slides with trail particles
        if (transferEvents.Count > 0)
        {
            var eventsToAnimate = transferEvents.ToList();

            tween.TweenCallback(Callable.From(() =>
            {
                bool hasDelivery = false;
                foreach (var evt in eventsToAnimate)
                {
                    if (evt is CargoTransferredEvent transfer)
                    {
                        if (transfer.GivingPieceId != null && _pieceViews.ContainsKey(transfer.GivingPieceId.Value))
                            _pieceViews[transfer.GivingPieceId.Value].SetCargo(null);

                        SpawnCargoSlide(transfer);

                        if (transfer.ReceivingPieceId == null) hasDelivery = true;
                    }
                }
                if (hasDelivery)
                    SfxManager.Instance?.PlayDeliver();
                else
                    SfxManager.Instance?.PlayTransfer();
            }));

            tween.TweenInterval(TransferDuration);
            tween.TweenCallback(Callable.From(() =>
            {
                foreach (var evt in eventsToAnimate)
                {
                    if (evt is CargoTransferredEvent transfer)
                    {
                        if (transfer.ReceivingPieceId != null && _pieceViews.ContainsKey(transfer.ReceivingPieceId.Value))
                            _pieceViews[transfer.ReceivingPieceId.Value].SetCargo(transfer.Type);
                    }
                    else if (evt is DemandProgressEvent progress)
                    {
                        _objectivePanel.UpdateProgress(progress.DemandCell, progress.Name, progress.Current, progress.Required);
                    }
                }
            }));

            transferEvents.Clear();
        }

        // Phase 3: Movement — simultaneous, with sfx
        if (moveEvents.Count > 0)
        {
            tween.TweenCallback(Callable.From(() => SfxManager.Instance?.PlayMove()));
            tween.SetParallel(true);
            foreach (var moved in moveEvents)
            {
                if (_pieceViews.TryGetValue(moved.PieceId, out var pv))
                {
                    var target = _boardView.CoordsToPixel(moved.To);
                    float duration = pv.Kind == PieceKind.Knight ? KnightMoveDuration : MoveDuration;
                    tween.TweenProperty(pv, "position", target, duration)
                        .SetEase(Tween.EaseType.InOut).SetTrans(Tween.TransitionType.Sine);
                }
            }
            tween.SetParallel(false);
            moveEvents.Clear();
        }

        // Phase 4: Collision — piece returned to stock (shrink + spin + particles)
        if (collisionEvents.Count > 0)
        {
            var captured = collisionEvents.ToList();
            tween.TweenCallback(Callable.From(() =>
            {
                SfxManager.Instance?.PlayDestroy();
                foreach (var returned in captured)
                {
                    if (_pieceViews.TryGetValue(returned.PieceId, out var pv))
                    {
                        SpawnDestroyParticles(pv.Position);

                        var dt = pv.CreateTween();
                        dt.SetParallel(true);
                        dt.TweenProperty(pv, "scale", Vector2.Zero, DestroyDuration)
                            .SetEase(Tween.EaseType.In).SetTrans(Tween.TransitionType.Back);
                        dt.TweenProperty(pv, "rotation", Mathf.Pi * 2f, DestroyDuration);
                        dt.TweenProperty(pv, "modulate:a", 0f, DestroyDuration);
                    }
                }

                // Emit signal for Main to pan camera + show toast
                var first = captured[0];
                EmitSignal(SignalName.CollisionOccurred,
                    first.Cell.Col, first.Cell.Row, first.Kind.ToString(),
                    first.DestroyerPieceId ?? -1);
            }));
            tween.TweenInterval(DestroyDuration);
            tween.TweenCallback(Callable.From(() =>
            {
                foreach (var returned in captured)
                    UnregisterPiece(returned.PieceId);
            }));
            collisionEvents.Clear();
        }
    }

    // --- Visual Effects ---

    private void SpawnCargoSlide(CargoTransferredEvent transfer)
    {
        var from = _boardView.CoordsToPixel(transfer.From);
        var to = _boardView.CoordsToPixel(transfer.To);
        var color = GetCargoColor(transfer.Type);

        var container = new Node2D { Position = from };
        _boardView.AddChild(container);

        // Main cargo square
        var main = new ColorRect
        {
            Size = new Vector2(12, 12),
            Position = new Vector2(-6, -6),
            Color = color,
            MouseFilter = Control.MouseFilterEnum.Ignore
        };
        container.AddChild(main);

        // Trail particles (2 smaller squares that follow with delay)
        for (int i = 1; i <= 2; i++)
        {
            float trailDelay = i * 0.04f;
            float trailSize = 12f - i * 3f;
            float trailAlpha = 0.6f - i * 0.2f;

            var trail = new ColorRect
            {
                Size = new Vector2(trailSize, trailSize),
                Position = new Vector2(-trailSize / 2f, -trailSize / 2f),
                Color = new Color(color, trailAlpha),
                MouseFilter = Control.MouseFilterEnum.Ignore
            };
            var trailContainer = new Node2D { Position = from };
            trailContainer.AddChild(trail);
            _boardView.AddChild(trailContainer);

            var trailTween = trailContainer.CreateTween();
            trailTween.TweenInterval(trailDelay);
            trailTween.TweenProperty(trailContainer, "position", to, TransferDuration - trailDelay)
                .SetEase(Tween.EaseType.Out).SetTrans(Tween.TransitionType.Back);
            trailTween.TweenCallback(Callable.From(() => trailContainer.QueueFree()));
        }

        // Main slide with whip easing
        var slideTween = container.CreateTween();
        slideTween.TweenProperty(container, "position", to, TransferDuration)
            .SetEase(Tween.EaseType.Out).SetTrans(Tween.TransitionType.Back);
        slideTween.TweenCallback(Callable.From(() => container.QueueFree()));
    }

    private void SpawnProduceParticles(Coords cell, CargoType type)
    {
        var center = _boardView.CoordsToPixel(cell);
        var color = GetCargoColor(type);
        var rng = new Random();

        for (int i = 0; i < 6; i++)
        {
            float angle = i * Mathf.Pi * 2f / 6f + (float)rng.NextDouble() * 0.5f;
            float dist = 25f + (float)rng.NextDouble() * 15f;
            float size = 4f + (float)rng.NextDouble() * 4f;

            var particle = new ColorRect
            {
                Size = new Vector2(size, size),
                Position = new Vector2(-size / 2f, -size / 2f),
                Color = new Color(color, 0.8f),
                MouseFilter = Control.MouseFilterEnum.Ignore
            };
            var pNode = new Node2D { Position = center };
            pNode.AddChild(particle);
            _boardView.AddChild(pNode);

            var target = center + new Vector2(Mathf.Cos(angle), Mathf.Sin(angle)) * dist;
            var pt = pNode.CreateTween();
            pt.SetParallel(true);
            pt.TweenProperty(pNode, "position", target, ProduceDuration * 0.8f)
                .SetEase(Tween.EaseType.Out).SetTrans(Tween.TransitionType.Cubic);
            pt.TweenProperty(pNode, "modulate:a", 0f, ProduceDuration);
            pt.SetParallel(false);
            pt.TweenCallback(Callable.From(() => pNode.QueueFree()));
        }
    }

    private void SpawnDestroyParticles(Vector2 position)
    {
        var rng = new Random();
        var red = new Color(0.9f, 0.25f, 0.2f);

        for (int i = 0; i < 10; i++)
        {
            float angle = (float)rng.NextDouble() * Mathf.Pi * 2f;
            float dist = 20f + (float)rng.NextDouble() * 30f;
            float size = 3f + (float)rng.NextDouble() * 5f;

            var particle = new ColorRect
            {
                Size = new Vector2(size, size),
                Position = new Vector2(-size / 2f, -size / 2f),
                Color = new Color(red, 0.9f),
                MouseFilter = Control.MouseFilterEnum.Ignore
            };
            var pNode = new Node2D { Position = position };
            pNode.AddChild(particle);
            _boardView.AddChild(pNode);

            var target = position + new Vector2(Mathf.Cos(angle), Mathf.Sin(angle)) * dist;
            var pt = pNode.CreateTween();
            pt.SetParallel(true);
            pt.TweenProperty(pNode, "position", target, DestroyDuration * 0.7f)
                .SetEase(Tween.EaseType.Out).SetTrans(Tween.TransitionType.Cubic);
            pt.TweenProperty(pNode, "modulate:a", 0f, DestroyDuration);
            pt.TweenProperty(pNode, "scale", Vector2.Zero, DestroyDuration)
                .SetEase(Tween.EaseType.In);
            pt.SetParallel(false);
            pt.TweenCallback(Callable.From(() => pNode.QueueFree()));
        }
    }

    private void SpawnConfetti()
    {
        var rng = new Random();
        var viewport = GetViewport().GetVisibleRect().Size;
        Color[] confettiColors = [
            new("#FFD700"), new("#FF6B35"), new("#3D8E5A"),
            new("#4A7AB5"), new("#B54A8E"), new("#E8D5A8")
        ];

        for (int i = 0; i < 40; i++)
        {
            float x = (float)rng.NextDouble() * viewport.X;
            float startY = -20f;
            float endY = viewport.Y + 50f;
            float size = 4f + (float)rng.NextDouble() * 6f;
            float duration = 1.5f + (float)rng.NextDouble() * 1.5f;
            float delay = (float)rng.NextDouble() * 0.5f;
            float drift = ((float)rng.NextDouble() - 0.5f) * 80f;

            var confetti = new ColorRect
            {
                Size = new Vector2(size, size * 0.5f),
                Color = confettiColors[rng.Next(confettiColors.Length)],
                MouseFilter = Control.MouseFilterEnum.Ignore
            };

            // Confetti needs to be in screen space (CanvasLayer)
            var parent = GetTree().Root;
            var cNode = new Node2D { Position = new Vector2(x, startY) };
            cNode.AddChild(confetti);
            parent.AddChild(cNode);

            var ct = cNode.CreateTween();
            ct.TweenInterval(delay);
            ct.SetParallel(true);
            ct.TweenProperty(cNode, "position", new Vector2(x + drift, endY), duration)
                .SetEase(Tween.EaseType.In).SetTrans(Tween.TransitionType.Sine);
            ct.TweenProperty(cNode, "rotation", (float)rng.NextDouble() * Mathf.Pi * 4f, duration);
            ct.SetParallel(false);
            ct.TweenCallback(Callable.From(() => cNode.QueueFree()));
        }
    }

    private static Color GetCargoColor(CargoType type) => type switch
    {
        CargoType.Wood => WoodCargoColor,
        CargoType.Stone => StoneCargoColor,
        CargoType.Tools => ToolsCargoColor,
        CargoType.Arms => ArmsCargoColor,
        CargoType.Gold => GoldCargoColor,
        _ => Colors.White
    };

    public void ResetPiecePositions(BoardSnapshot snapshot)
    {
        foreach (var ps in snapshot.Pieces)
        {
            if (_pieceViews.TryGetValue(ps.Id, out var pv))
            {
                pv.Position = _boardView.CoordsToPixel(ps.StartCell);
                pv.SetCargo(null);
            }
        }
    }

    public void ClearAll()
    {
        foreach (var pv in _pieceViews.Values)
            pv.QueueFree();
        foreach (var tv in _trajectViews.Values)
            tv.QueueFree();
        _pieceViews.Clear();
        _trajectViews.Clear();
    }
}