using System;
using System.Collections.Generic;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.UIElements;

namespace DanieleMarotta.RiversongCodeShowcase
{
    public class BuildingBadgeUIController : UIControllerSystem, IInitializable, IDisposable, IUpdatable
    {
        [InjectService]
        private ISignalBus _signalBus;

        [InjectService]
        private IWorldUIService _worldUIService;

        [InjectService]
        private ICameraProperties _cameraProperties;

        [InjectService]
        private GameConfig _gameConfig;

        [InjectService]
        private World _world;

        private VisualElement _container;

        private readonly Dictionary<int, BadgeEntry> _entries = new();

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

        public override async UniTask InitializeAsync()
        {
            await base.InitializeAsync();

            _container = UIRoot.RootVisualElement.Q(className: "world-ui-layer");

            _signalBus.Subscribe<BuildingVisualizationCreatedSignal>(OnBuildingVisualizationCreated);
            _signalBus.Subscribe<BuildingDeletedSignal>(OnBuildingDeleted);
        }

        public void Dispose()
        {
            _signalBus.Unsubscribe<BuildingVisualizationCreatedSignal>(OnBuildingVisualizationCreated);
            _signalBus.Unsubscribe<BuildingDeletedSignal>(OnBuildingDeleted);
        }

        private void OnBuildingVisualizationCreated(BuildingVisualizationCreatedSignal signal)
        {
            var building = signal.Building;
            if (building.Definition.WorkerCount <= 0) return;

            CreateBadgeAsync(building, signal.Visualization).Forget();
        }

        private async UniTask CreateBadgeAsync(Building building, BuildingVisualization visualization)
        {
            var element = UIService.TemplateLibrary.WorldUI.Badge.CloneTree();
            _container.Add(element);

            var view = (BuildingBadgeUIView)await UIService.CreateView(typeof(BuildingBadgeUIView), element);
            view.RootElement.SetPickingModeRecursive(PickingMode.Ignore);
            view.Show(false);

            _worldUIService.Register(view.RootElement, visualization.transform);

            _entries.Add(building.Id, new BadgeEntry(building, view));
        }

        private void OnBuildingDeleted(BuildingDeletedSignal signal)
        {
            if (!_entries.Remove(signal.Building.Id, out var entry)) return;

            _worldUIService.Unregister(entry.View.RootElement);
            entry.View.RootElement.RemoveFromHierarchy();
        }

        public void Update()
        {
            var zoomRange = _gameConfig.Camera.ZoomRange;
            var config = UIService.TemplateLibrary.WorldUI;

            var normalizedZoom = Mathf.InverseLerp(zoomRange.x, config.BadgeZoomCullThreshold, _cameraProperties.Zoom);
            var offset = Mathf.Lerp(config.BadgeYOffset.x, config.BadgeYOffset.y, normalizedZoom);
            var scale = Mathf.Lerp(config.BadgeScale.x, config.BadgeScale.y, normalizedZoom);

            var culledByZoom = _cameraProperties.Zoom > config.BadgeZoomCullThreshold;
            UpdateBadges(culledByZoom);

            foreach (var entry in _entries.Values)
            {
                entry.View.RootElement.SetScale(scale);

                _worldUIService.SetWorldOffset(entry.View.RootElement, offset * Vector3.up);
            }
        }

        private void UpdateBadges(bool culledByZoom)
        {
            foreach (var entry in _entries.Values)
            {
                ref var sleepState = ref entry.Building.GetSleepStateRW();

                var show = !culledByZoom && _world.TimeState.DayNightCycleStep == DayNightCycleStep.Day && sleepState.HasHomelessWorkers;

                entry.View.Show(show);
            }
        }

        private readonly struct BadgeEntry
        {
            public readonly Building Building;

            public readonly BuildingBadgeUIView View;

            public BadgeEntry(Building building, BuildingBadgeUIView view)
            {
                Building = building;
                View = view;
            }
        }
    }
}