using System;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.InputSystem;
using UnityEngine.TextCore.Text;
using UnityEngine.UIElements;

namespace DanieleMarotta.RiversongCodeShowcase
{
    [GameSystemGroup(typeof(UISystemGroup))]
    [InitializeAfter(typeof(UIInitializationSystem))]
    public class DebugPanelUIControllerSystem : UIControllerSystem, IUpdatable, IDisposable
    {
        [InjectService]
        private GameConfig _config;

        [InjectService]
        private ISignalBus _signalBus;

        [InjectService]
        private IPointerService _pointerService;

        [InjectService]
        private ITileSpace _tileSpace;

        [InjectService]
        private World _world;

        private UIElementReferences _elements = new();

        private FontAsset _font;

        private Building _selectedBuilding;

        private bool _isVisible;

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

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

            _font = await _config.UI.DebugFont.LoadAssetAsync<FontAsset>();

            _elements.PanelRoot = CreatePanelRoot();
            InitializePanelContent();

            UIRoot.RootVisualElement.Add(_elements.PanelRoot);

            _signalBus.Subscribe<SelectedBuildingChangedSignal>(OnSelectedBuildingChanged);
        }

        public void Dispose()
        {
            _signalBus.Unsubscribe<SelectedBuildingChangedSignal>(OnSelectedBuildingChanged);
        }

        private void InitializePanelContent()
        {
            _elements.PanelRoot.Add(CreateHeader("DEBUG PANEL"));

            InitializePointerSection();
            InitializePopulationSection();
            InitializeSelectedBuildingSection();
        }

        private void InitializePointerSection()
        {
            _elements.TileCoordsLabel = CreateLabel("Tile: ");
            _elements.PanelRoot.Add(_elements.TileCoordsLabel);
        }

        private void InitializePopulationSection()
        {
            _elements.PanelRoot.Add(CreateHeader("POPULATION"));

            _elements.PopulationCapacityLabel = CreateLabel("Capacity: ");
            _elements.PanelRoot.Add(_elements.PopulationCapacityLabel);

            _elements.PopulationGrowthAccumulatorLabel = CreateLabel("Growth Accumulator: ");
            _elements.PanelRoot.Add(_elements.PopulationGrowthAccumulatorLabel);
        }

        private void InitializeSelectedBuildingSection()
        {
            _elements.PanelRoot.Add(CreateHeader("SELECTED BUILDING"));

            _elements.SelectedBuildingFallbackLabel = CreateLabel("No building selected");
            _elements.PanelRoot.Add(_elements.SelectedBuildingFallbackLabel);

            _elements.SelectedBuildingNameLabel = CreateLabel("Building: ");
            _elements.PanelRoot.Add(_elements.SelectedBuildingNameLabel);

            InitializeSelectedHouseContent();
        }

        private void InitializeSelectedHouseContent()
        {
            _elements.SelectedHouseContent = new VisualElement { style = { display = DisplayStyle.None } };

            _elements.SelectedBuildingTierLabel = CreateLabel("Tier: ");
            _elements.SelectedHouseContent.Add(_elements.SelectedBuildingTierLabel);

            _elements.SelectedBuildingHappinessLabel = CreateLabel("Happiness: ");
            _elements.SelectedHouseContent.Add(_elements.SelectedBuildingHappinessLabel);

            _elements.SelectedBuildingMaxHappinessScoreLabel = CreateLabel("Max Happiness Score: ");
            _elements.SelectedHouseContent.Add(_elements.SelectedBuildingMaxHappinessScoreLabel);

            _elements.SelectedBuildingOverallWeightLabel = CreateLabel("Overall Weight: ");
            _elements.SelectedHouseContent.Add(_elements.SelectedBuildingOverallWeightLabel);

            _elements.SelectedBuildingAllNeedsMetLabel = CreateLabel("All Needs Met: ");
            _elements.SelectedHouseContent.Add(_elements.SelectedBuildingAllNeedsMetLabel);

            _elements.SelectedBuildingNeedsMetForWeeksLabel = CreateLabel("Needs Met For Weeks: ");
            _elements.SelectedHouseContent.Add(_elements.SelectedBuildingNeedsMetForWeeksLabel);

            _elements.PanelRoot.Add(_elements.SelectedHouseContent);
        }

        public void Update()
        {
            if (Keyboard.current.f9Key.wasPressedThisFrame)
            {
                _isVisible = !_isVisible;
                _elements.PanelRoot.style.display = _isVisible ? DisplayStyle.Flex : DisplayStyle.None;
            }

            if (!_isVisible) return;

            UpdatePointerSection();
            UpdatePopulationSection();
            UpdateSelectedBuildingSection();
        }

        private void UpdatePointerSection()
        {
            if (_pointerService.TryGetPositionOnTerrain(out var position))
            {
                var tile = _tileSpace.WorldToTile(position);
                _elements.TileCoordsLabel.text = $"Tile: {tile.x}, {tile.y}";
            }
            else
            {
                _elements.TileCoordsLabel.text = "Tile: -";
            }
        }

        private void UpdatePopulationSection()
        {
            var populationState = _world.PopulationState;
            _elements.PopulationCapacityLabel.text = $"Capacity: {populationState.PopulationCapacity}";
            _elements.PopulationGrowthAccumulatorLabel.text = $"Growth Accumulator: {populationState.GrowthAccumulator:0.000}";
        }

        private void UpdateSelectedBuildingSection()
        {
            var anyBuildingSelected = _selectedBuilding != null;
            var houseSelected = anyBuildingSelected && _selectedBuilding.Definition.IsHouse;

            _elements.SelectedBuildingFallbackLabel.style.display = anyBuildingSelected ? DisplayStyle.None : DisplayStyle.Flex;
            _elements.SelectedBuildingNameLabel.style.display = anyBuildingSelected ? DisplayStyle.Flex : DisplayStyle.None;
            _elements.SelectedHouseContent.style.display = houseSelected ? DisplayStyle.Flex : DisplayStyle.None;

            if (!anyBuildingSelected) return;

            _elements.SelectedBuildingNameLabel.text = $"Building: {_selectedBuilding.Definition.BuildingName} ({_selectedBuilding.Id})";

            if (houseSelected) UpdateSelectedHouseInfo();
        }

        private void UpdateSelectedHouseInfo()
        {
            ref var needsState = ref _selectedBuilding.GetNeedsStateRW();

            _elements.SelectedBuildingTierLabel.text = $"Tier: {_selectedBuilding.TierIndex}";
            _elements.SelectedBuildingHappinessLabel.text = $"Happiness: {needsState.Happiness:0.000}";
            _elements.SelectedBuildingMaxHappinessScoreLabel.text = $"Max Happiness Score: {Mathf.FloorToInt(needsState.MaxHappinessScore)}";
            _elements.SelectedBuildingOverallWeightLabel.text = $"Overall Weight: {needsState.OverallHappinessWeight:0.000}";
            _elements.SelectedBuildingAllNeedsMetLabel.text = $"All Needs Met: {needsState.AllNeedsMet}";
            _elements.SelectedBuildingNeedsMetForWeeksLabel.text = $"Needs Met For Weeks: {needsState.NeedsMetForWeeks}";
        }

        private void OnSelectedBuildingChanged(SelectedBuildingChangedSignal signal)
        {
            _selectedBuilding = signal.NewSelection;

            UpdateSelectedBuildingSection();
        }

        private VisualElement CreatePanelRoot()
        {
            const int panelWidth = 350;

            var panelRoot = new VisualElement
            {
                name = "debug-panel",
                pickingMode = PickingMode.Position,
                style =
                {
                    position = Position.Absolute,
                    top = 16,
                    left = Screen.width - panelWidth - 16,
                    width = panelWidth,
                    paddingTop = 12,
                    paddingRight = 12,
                    paddingBottom = 12,
                    paddingLeft = 12,
                    backgroundColor = new StyleColor(new Color(0, 0, 0, 0.7f)),
                    borderTopLeftRadius = 8,
                    borderTopRightRadius = 8,
                    borderBottomLeftRadius = 8,
                    borderBottomRightRadius = 8,
                    display = DisplayStyle.None
                }
            };

            panelRoot.AddToClassList("drag-target");

            UIRoot.MakeDraggable(panelRoot);

            return panelRoot;
        }

        private Label CreateLabel(string text, FontAsset font = null, int fontSize = 14, FontStyle fontStyle = FontStyle.Normal, int marginBottom = 0)
        {
            var label = new Label(text);
            label.pickingMode = PickingMode.Ignore;
            label.style.color = Color.white;
            label.style.unityFontDefinition = FontDefinition.FromSDFFont(font ?? _font);
            label.style.unityFontStyleAndWeight = fontStyle;
            label.style.fontSize = fontSize;
            label.style.marginBottom = marginBottom;
            return label;
        }

        private Label CreateHeader(string text)
        {
            var header = CreateLabel(text, fontSize: 16, fontStyle: FontStyle.Bold, marginBottom: 8);
            header.pickingMode = PickingMode.Position;
            header.AddToClassList("drag-handle");
            return header;
        }

        private class UIElementReferences
        {
            public VisualElement PanelRoot;

            public Label TileCoordsLabel;

            public Label PopulationCapacityLabel;

            public Label PopulationGrowthAccumulatorLabel;

            public Label SelectedBuildingFallbackLabel;

            public VisualElement SelectedHouseContent;

            public Label SelectedBuildingNameLabel;

            public Label SelectedBuildingTierLabel;

            public Label SelectedBuildingHappinessLabel;

            public Label SelectedBuildingMaxHappinessScoreLabel;

            public Label SelectedBuildingOverallWeightLabel;

            public Label SelectedBuildingAllNeedsMetLabel;

            public Label SelectedBuildingNeedsMetForWeeksLabel;
        }
    }
}