using System;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.Pool;
using IServiceProvider = DanieleMarotta.RiversongCodeShowcase.IServiceProvider;

namespace DanieleMarotta.RiversongCodeShowcase
{
    [RequiresWorldReadyForUpdate]
    public class EditingStateGameSystem : GameSystem, IServiceProvider, IInitializable, IDisposable, IUpdatable, IEditingService
    {
        [InjectService]
        private ICancelAction _cancelAction;

        [InjectService]
        private WorldRenderingState _renderingState;

        [InjectService]
        private GameConfig _config;

        [InjectService]
        private World _world;

        [InjectService]
        private ISignalBus _signalBus;

        [InjectService]
        private MaterialReplacementCache _materialReplacementCache;

        public EditingStateGameSystem(IServiceLocator serviceLocator) : base(serviceLocator)
        {
        }

        public EditingState EditingState { get; private set; }

        public event Action<EditTool> ActiveToolChanged;

        public void RegisterServices(IServiceLocator serviceLocator)
        {
            serviceLocator.RegisterService<IEditingService>(this);

            EditingState = new EditingState();
            serviceLocator.RegisterService(EditingState);
        }

        public async UniTask InitializeAsync()
        {
            EditingState.BuildTool = new BuildTool(ServiceLocator);
            EditingState.DeleteTool = new DeleteTool(ServiceLocator);
            EditingState.RoadTool = new RoadTool(ServiceLocator);
            await EditingState.InitializeAsync();

            _cancelAction.AddHandler(
                (int)CancelActions.CancelEditTool,
                _ =>
                {
                    if (EditingState.ActiveTool == null) return false;

                    DeactivateTool();

                    return true;
                });
        }

        public void Dispose()
        {
            EditingState?.Dispose();
            EditingState = null;
        }

        public void ActivateTool(EditTool tool)
        {
            EditingState.ActiveTool?.OnDisabled();
            EditingState.ActiveTool = tool;
            EditingState.ActiveTool?.OnEnabled();

            ActiveToolChanged?.Invoke(EditingState.ActiveTool);
        }

        public void DeactivateTool()
        {
            ActivateTool(null);
        }

        public void Update()
        {
            UpdateActiveTool();
            UpdateHighlightedGameObjects();
        }

        private void UpdateActiveTool()
        {
            if (EditingState.ActiveTool == null) return;

            EditingState.ActiveTool.Update();

            UpdateAffectedTiles();
            UpdateDeletedGameObjects();
        }

        private void UpdateAffectedTiles()
        {
            foreach (var (tile, type) in EditingState.ActiveTool.AffectedTiles)
            {
                if (_world.BlockMap.IsBlocked(tile, BlockReason.InvalidElevation)) continue;

                Color32 color;
                var config = _config.UI.TileHighlight;
                switch (type)
                {
                    case TileHighlightType.ValidTile:
                        color = config.ValidColor;
                        break;

                    case TileHighlightType.InvalidTile:
                        color = config.InvalidColor;
                        break;

                    case TileHighlightType.DeletePreview:
                        color = config.DeletePreviewColor;
                        break;

                    default:
                        color = Color.magenta;
                        break;
                }

                _renderingState.TileHighlight.AddTile(tile, color);
            }
        }

        private void UpdateDeletedGameObjects()
        {
            EditingState.ActiveTool.GetDeleteGameObjectsPreviewInfo(out var filter, out var rect);
            if (filter == DeletedGameObjectsFilter.None) return;

            using var gameObjectsScope = ListPool<GameObject>.Get(out var gameObjects);
            _signalBus.Raise(new CollectDeletedGameObjectsSignal(filter, rect, gameObjects));

            _materialReplacementCache.ReplaceMaterials(gameObjects, _config.UI.DeletedGameObjectsMaterial);
        }

        private void UpdateHighlightedGameObjects()
        {
            using var gameObjectsScope = ListPool<GameObject>.Get(out var gameObjects);
            _signalBus.Raise(new CollectHighlightedGameObjectsSignal(gameObjects));

            _materialReplacementCache.ReplaceMaterials(gameObjects, _config.UI.HighlightedGameObjectsMaterial);
        }
    }
}