using System;
using System.Collections.Generic;
using System.Linq;
using AibisDream.Framework;
using AibisDream.UI;
using AibisDream.Utility;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace AibisDream
{
    public class UIManager : Kit.Singleton<UIManager>, IUIManager
    {
        #region 索引

        private Dictionary<Type, IUIPanel> _panelPool;
        private readonly Stack<IUIPanel> _panelStack = new();

        public RectTransform Canvas { get; private set; }
        public Vector2 Resolution { get; set; }

        public Camera UICamera { get; private set; }
        public RectTransform DialogCanvas { get; private set; }

        private GraphicRaycaster _raycaster;
        private EventSystem _pointerEventSystem;
        private PointerEventData _pointerEventData;
        private readonly List<RaycastResult> _pointerRaycastResults = new();
        private DeveloperModePanel _developerModePanel;

        #endregion

        public override void OnSingletonInit()
        {
            InitRefs();
        }

        private void Update()
        {
            if (Input.GetKeyDown(KeyCode.Escape))
            {
                if (DeveloperModeGate.IsEnabled && _developerModePanel != null
                    && _developerModePanel.HandleEscape())
                {
                    return;
                }

                if (TryGetPanel<InGameTerminalPanel>(out var inGameTerminal) && inGameTerminal.HandleEscape())
                {
                    return;
                }

                if (TryGetPanel<TerminalPanel>(out var terminal) && terminal.HandleEscape())
                {
                    return;
                }

                if (GameManager.Instance != null && GameManager.Session.CanPause)
                {
                    GetPanel<InGameTerminalPanel>()?.Open(InGameTerminalPage.Setting);
                }
            }

            if (DeveloperModeGate.IsEnabled
                && (Input.GetKey(KeyCode.LeftControl) || Input.GetKey(KeyCode.RightControl))
                && Input.GetKeyDown(KeyCode.R))
            {
                _developerModePanel?.TogglePanel();
            }
        }

        private void InitRefs()
        {
            UICamera = transform.Find("UI Camera").GetComponent<Camera>();
            // 获取Canvas
            Canvas = transform.Find("UI Canvas").GetComponent<RectTransform>();
            DialogCanvas = transform.Find("Dialog Canvas").GetComponent<RectTransform>();
            // 获取 GraphicRaycaster
            _raycaster = Canvas.GetComponent<GraphicRaycaster>();
            _developerModePanel = GetComponentsInChildren<DeveloperModePanel>(true)
                .FirstOrDefault(panel => panel.IsConfigured);
            if (_developerModePanel == null)
            {
                var infoPanel = transform.Find("UI Canvas/Info Panel");
                if (infoPanel != null)
                {
                    _developerModePanel = infoPanel.GetComponentsInChildren<DeveloperModePanel>(true)
                        .FirstOrDefault(panel => panel.IsConfigured);
                }
            }
            // 获取Panel
            var panels = Canvas.GetComponentsInChildren<IUIPanel>(true);
            _panelPool = new Dictionary<Type, IUIPanel>();
            foreach (var panel in panels)
            {
                _panelPool[panel.GetType()] = panel;
                panel.Initialize();
            }

            EnumEventSystem.Global.Register(GameLifecycleEvent.ApplicationReady, OnAppStart);
            EnumEventSystem.Global.Register(GameLifecycleEvent.SessionStarted, OnGameStart);
            EnumEventSystem.Global.Register(GameLifecycleEvent.SessionEnded, OnGameQuit);
        }

        private void OnAppStart()
        {
            // 游戏打开
            ShowPanel<TerminalPanel>();
            ShowPanel<PlayToolPanel>();
            ShowPanel<ScreenTransitionPanel>();

            HidePanel<MainPanel>();
            HidePanel<InGameTerminalPanel>();
            HidePanel<EndPanel>();
        }

        private void OnGameStart()
        {
            // 开始游戏
            HidePanel<TerminalPanel>();
            HidePanel<InGameTerminalPanel>();
            ShowPanel<MainPanel>();
        }

        private void OnGameQuit()
        {
            HidePanel<MainPanel>();
            ShowPanel<TerminalPanel>();
        }

        public void ShowPanel<T>(Action<T> call = null) where T : class, IUIPanel
        {
            var type = typeof(T);
            // 从缓存中检查panel
            if (_panelPool.TryGetValue(type, out var panel))
            {
                if (panel.IsOpen) return;
                if (panel.IsCloseable) _panelStack.Push(panel);
                panel.Show();
                call?.Invoke(panel as T);
            }
            else
            {
                Debug.Log($"panel {type} 未注册");
            }
        }

        public void HidePanel<T>() where T : IUIPanel
        {
            var type = typeof(T);
            // 从缓存中检查panel
            if (_panelPool.TryGetValue(type, out var panel))
            {
                if (!panel.IsOpen) return;
                if (panel.IsCloseable) _panelStack.Pop();
                panel.Hide();
            }
            else
            {
                Debug.Log($"panel {type} 未注册");
            }
        }

        private void HidePanel<T>(T panel) where T : IUIPanel
        {
            if (_panelPool.ContainsValue(panel))
            {
                if (!panel.IsOpen) return;
                if (panel.IsCloseable) _panelStack.Pop();
                panel.Hide();
            }
            else
            {
                Debug.Log($"panel {typeof(T)} 未注册");
            }
        }

        public T GetPanel<T>() where T : class, IUIPanel
        {
            if (_panelPool.TryGetValue(typeof(T), out var panel))
            {
                return panel as T;
            }

            Debug.Log($"没有找到{typeof(T)}");
            return null;
        }

        public bool TryGetPanel<T>(out T panel) where T : class, IUIPanel
        {
            panel = null;
            if (_panelPool == null)
            {
                return false;
            }

            if (_panelPool.TryGetValue(typeof(T), out var rawPanel))
            {
                panel = rawPanel as T;
            }

            return panel != null;
        }

        public void ShowPreferredLoading()
        {
            if (TryGetPanel<TerminalLoadingPanel>(out var terminalLoading))
            {
                ShowPanel<TerminalLoadingPanel>();
                terminalLoading.SetProgress(0f);
            }
            else
            {
                GetPanel<InfoPanel>()?.ShowLoading();
            }
        }

        public void SetPreferredLoadingProgress(float progress)
        {
            if (TryGetPanel<TerminalLoadingPanel>(out var terminalLoading))
            {
                terminalLoading.SetProgress(progress);
            }
        }

        public void HidePreferredLoading()
        {
            if (TryGetPanel<TerminalLoadingPanel>(out _))
            {
                HidePanel<TerminalLoadingPanel>();
            }

            GetPanel<InfoPanel>()?.HideLoading();
        }

        public static Vector3 GetDialogUIPos(Vector3 screenPos)
        {
            // 转换为UI坐标
            RectTransformUtility.ScreenPointToLocalPointInRectangle(
                Instance.DialogCanvas,
                screenPos,
                Instance.UICamera,
                out Vector2 localPoint);

            return localPoint;
        }

        public bool ScreenPointToLocalPointInRectangle(RectTransform rectTransform, Vector2 screenPos, out Vector2 localPoint)
        {
            return RectTransformUtility.ScreenPointToLocalPointInRectangle(rectTransform, screenPos, UICamera, out localPoint);
        }

        /// <summary>
        /// 检查屏幕坐标是否命中主 UI Canvas 上会接收射线的元素。
        /// 对话 Canvas 不在此范围内，因此点击对话画面本身仍可正常推进。
        /// </summary>
        public bool IsPointerOverUI(Vector2 screenPosition)
        {
            var eventSystem = EventSystem.current;
            if (eventSystem == null || _raycaster == null)
            {
                return false;
            }

            if (_pointerEventData == null || _pointerEventSystem != eventSystem)
            {
                _pointerEventSystem = eventSystem;
                _pointerEventData = new PointerEventData(eventSystem);
            }

            _pointerEventData.Reset();
            _pointerEventData.position = screenPosition;

            _pointerRaycastResults.Clear();
            _raycaster.Raycast(_pointerEventData, _pointerRaycastResults);
            if (_pointerRaycastResults.Count == 0)
            {
                return false;
            }

            var topResult = _pointerRaycastResults[0];
            return topResult.gameObject.GetComponentInParent<AllowDialogueAdvanceOnPointer>() == null;
        }

        /// <summary>
        /// 检查鼠标是否在指定标记的 UI 区域上
        /// </summary>
        /// <param name="regionTag">区域标识符，需要在 UIRegionMarker 组件中配置</param>
        /// <returns>如果鼠标在指定区域上返回 true，否则返回 false</returns>
        public bool IsOverRegion(string regionTag)
        {
            if (string.IsNullOrEmpty(regionTag))
            {
                return false;
            }

            // 如果鼠标不在 UI 上，直接返回 false
            if (!EventSystem.current.IsPointerOverGameObject())
            {
                return false;
            }

            // 使用 GraphicRaycaster 检测鼠标下的 UI 元素
            var eventData = new PointerEventData(EventSystem.current)
            {
                position = Input.mousePosition
            };

            var results = new List<RaycastResult>();
            _raycaster.Raycast(eventData, results);

            return results.Count > 0 && results.Any(result => result.gameObject.CompareTag(regionTag));
        }
    }

    public interface IUIManager
    {
        void ShowPanel<T>(Action<T> call = null) where T : class, IUIPanel;
        void HidePanel<T>() where T : IUIPanel;
        T GetPanel<T>() where T : class, IUIPanel;
        RectTransform Canvas { get; }
        Vector2 Resolution { get; set; }

        // 还没想好要不要用栈
        // UIPanel Pop();
        // void Push<T>(T panel) where T : UIPanel;
    }
}