using Dalamud.Bindings.ImGui;
using Dalamud.Game.ClientState.Objects.SubKinds;
using Dalamud.Game.ClientState.Objects.Types;
using Dalamud.Interface;
using Dalamud.Plugin;
using Dalamud.Plugin.Services;
using FFXIVClientStructs.FFXIV.Client.Game.Object;
using LightlessSync.LightlessConfiguration;
using LightlessSync.Services.Mediator;
using LightlessSync.UI;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using System.Collections.Immutable;
using System.Numerics;

namespace LightlessSync.Services.LightFinder
{
    public class LightFinderPlateHandler : IHostedService, IMediatorSubscriber
    {
        private readonly ILogger<LightFinderPlateHandler> _logger;
        private readonly LightlessConfigService _configService;
        private readonly IDalamudPluginInterface _pluginInterface;
        private readonly IObjectTable _gameObjects;
        private readonly IGameGui _gameGui;

        private const float _defaultNameplateDistance = 15.0f;
        private ImmutableHashSet<string> _activeBroadcastingCids = [];
        private readonly Dictionary<IGameObject, Vector3> _smoothed = [];
        private readonly float _defaultHeightOffset = 0f;

        public LightlessMediator Mediator { get; }

        public LightFinderPlateHandler(
            ILogger<LightFinderPlateHandler> logger,
            LightlessMediator mediator,
            IDalamudPluginInterface dalamudPluginInterface,
            LightlessConfigService configService,
            IObjectTable gameObjects,
            IGameGui gameGui)
        {
            _logger = logger;
            Mediator = mediator;
            _pluginInterface = dalamudPluginInterface;
            _configService = configService;
            _gameObjects = gameObjects;
            _gameGui = gameGui;
        }

        public Task StartAsync(CancellationToken cancellationToken)
        {
            _logger.LogInformation("Starting LightFinderPlateHandler...");

            _pluginInterface.UiBuilder.Draw += OnDraw;

            _logger.LogInformation("LightFinderPlateHandler started.");
            return Task.CompletedTask;
        }

        public Task StopAsync(CancellationToken cancellationToken)
        {
            _logger.LogInformation("Stopping LightFinderPlateHandler...");

            _pluginInterface.UiBuilder.Draw -= OnDraw;

            _logger.LogInformation("LightFinderPlateHandler stopped.");
            return Task.CompletedTask;
        }

        private unsafe void OnDraw()
        {
            if (!_configService.Current.BroadcastEnabled)
                return;

            if (_activeBroadcastingCids.Count == 0)
                return;

            var drawList = ImGui.GetForegroundDrawList();

            foreach (var obj in _gameObjects.PlayerObjects.OfType<IPlayerCharacter>())
            {
                //Double check to be sure, should always be true due to OfType filter above
                if (obj is not IPlayerCharacter player)
                    continue;

                if (player.Address == IntPtr.Zero)
                    continue;

                var hashedCID = DalamudUtilService.GetHashedCIDFromPlayerPointer(player.Address);
                if (!_activeBroadcastingCids.Contains(hashedCID))
                    continue;

                //Approximate check if nameplate should be visible (at short distances)
                if (!ShouldApproximateNameplateVisible(player))
                    continue;

                if (!TryGetApproxNameplateScreenPos(player, out var rawScreenPos))
                    continue;

                var rawVector3 = new Vector3(rawScreenPos.X, rawScreenPos.Y, 0f);

                if (rawVector3 == Vector3.Zero)
                {
                    _smoothed.Remove(obj);
                    continue;
                }

                //Possible have to rework this. Currently just a simple distance check to avoid jitter.
                Vector3 smoothedVector3;

                if (_smoothed.TryGetValue(obj, out var lastVector3))
                {
                    var deltaVector2 = new Vector2(rawVector3.X - lastVector3.X, rawVector3.Y - lastVector3.Y);
                    if (deltaVector2.Length() < 1f)
                        smoothedVector3 = lastVector3;
                    else
                        smoothedVector3 = rawVector3;
                }
                else
                {
                    smoothedVector3 = rawVector3;
                }

                _smoothed[obj] = smoothedVector3;

                var screenPos = new Vector2(smoothedVector3.X, smoothedVector3.Y);

                var radiusWorld = Math.Max(player.HitboxRadius, 0.5f);
                var radiusPx = radiusWorld * 8.0f;
                var offsetPx = GetScreenOffset(player);
                var drawPos = new Vector2(screenPos.X, screenPos.Y - offsetPx);

                var fillColor = ImGui.GetColorU32(UiSharedService.Color(UIColors.Get("Lightfinder")));
                var outlineColor = ImGui.GetColorU32(UiSharedService.Color(UIColors.Get("LightfinderEdge")));

                drawList.AddCircleFilled(drawPos, radiusPx, fillColor);
                drawList.AddCircle(drawPos, radiusPx, outlineColor, 0, 2.0f);

                var label = "LightFinder";
                var icon = FontAwesomeIcon.Bullseye.ToIconString();

                ImGui.PushFont(UiBuilder.IconFont); 
                var iconSize = ImGui.CalcTextSize(icon);
                var iconPos = new Vector2(drawPos.X - iconSize.X / 2f, drawPos.Y - radiusPx - iconSize.Y - 2f);
                drawList.AddText(iconPos, fillColor, icon);
                ImGui.PopFont();

                /* var scale = 1.4f;
                var font = ImGui.GetFont();
                var baseFontSize = ImGui.GetFontSize();
                var fontSize = baseFontSize * scale;

                var baseTextSize = ImGui.CalcTextSize(label);
                var textSize = baseTextSize * scale;

                var textPos = new Vector2(
                    drawPos.X - textSize.X / 2f,
                    drawPos.Y - radiusPx - textSize.Y - 2f
                );

                drawList.AddText(font, fontSize, textPos, fillColor, label); */
            }
        }

        // Get screen offset based on distance to local player (to scale size appropriately)
        // I need to fine tune these values still
        private float GetScreenOffset(IPlayerCharacter player)
        {
            var local = _gameObjects.LocalPlayer;
            if (local == null)
                return 32.1f;

            var delta = player.Position - local.Position;
            var dist = MathF.Sqrt(delta.X * delta.X + delta.Z * delta.Z);

            const float minDist = 2.1f;
            const float maxDist = 30.4f;
            dist = Math.Clamp(dist, minDist, maxDist);

            var t = 1f - (dist - minDist) / (maxDist - minDist);

            const float minOffset = 24.4f;
            const float maxOffset = 56.4f;
            return minOffset + (maxOffset - minOffset) * t;
        }

        private bool TryGetApproxNameplateScreenPos(IPlayerCharacter player, out Vector2 screenPos)
        {
            screenPos = default;

            var worldPos = player.Position;

            var visualHeight = GetVisualHeight(player);

            worldPos.Y += (visualHeight + 1.2f) + _defaultHeightOffset;

            if (!_gameGui.WorldToScreen(worldPos, out var raw))
                return false;

            screenPos = raw;
            return true;
        }

        // Approximate check to see if nameplate would be visible based on distance and screen position
        // Also has to be fine tuned still
        private bool ShouldApproximateNameplateVisible(IPlayerCharacter player)
        {
            var local = _gameObjects.LocalPlayer;
            if (local == null)
                return false;

            var delta = player.Position - local.Position;
            var distance2D = MathF.Sqrt(delta.X * delta.X + delta.Z * delta.Z);
            if (distance2D > _defaultNameplateDistance)
                return false;

            var verticalDelta = MathF.Abs(delta.Y);
            if (verticalDelta > 3.4f)
                return false;

            return TryGetApproxNameplateScreenPos(player, out _);
        }

        private static unsafe float GetVisualHeight(IPlayerCharacter player)
        {
            var gameObject = (GameObject*)player.Address;
            if (gameObject == null)
                return Math.Max(player.HitboxRadius * 2.0f, 1.7f); // fallback

            // This should account for transformations (sitting, crouching, etc.)
            var radius = gameObject->GetRadius(adjustByTransformation: true);
            if (radius <= 0)
                radius = Math.Max(player.HitboxRadius * 2.0f, 1.7f);

            return radius;
        }

        // Update the set of active broadcasting CIDs (Same uses as in NameplateHnadler before)
        public void UpdateBroadcastingCids(IEnumerable<string> cids)
        {
            var newSet = cids.ToImmutableHashSet(StringComparer.Ordinal);
            if (ReferenceEquals(_activeBroadcastingCids, newSet) || _activeBroadcastingCids.SetEquals(newSet))
                return;

            _activeBroadcastingCids = newSet;
            if (_logger.IsEnabled(LogLevel.Information))
                _logger.LogInformation("Active broadcast CIDs: {Cids}", string.Join(',', _activeBroadcastingCids));
        }
    }
}