using System;
using System.Collections;
using System.Collections.Generic;
using AibisDream.Kit;
using AibisDream.Utility;
using Cinemachine;
using DG.Tweening;
using DG.Tweening.Core;
using DG.Tweening.Plugins.Options;
using UnityEngine;
using UnityEngine.Rendering.Universal;
using Yarn.Unity;

namespace AibisDream.Framework
{
    public class CameraKit : Singleton<CameraKit>
    {
        private const int LowPriority = 1;
        private const int HighPriority = 10;

        #region 相机组件

        public static Camera UICamera => UIManager.Instance.UICamera;

        private CinemachineBrain _orthoCameraBrain;
        private readonly Dictionary<CameraEnum, ICinemachineCamera> _virtualCameraDict = new();
        private readonly Dictionary<CameraEnum, CamState> _camInitStateDict = new();

        private CameraEnum _curCameraEnum;
        private CamState _curInitState;
        private Camera _orthoMainCamera;
        private Tween _shakeTween;

        private struct CamState
        {
            public Vector3 pos;
            public float initOrthoSize;
        }

        #endregion

        private CameraKit()
        {
        }

        public override void OnSingletonInit()
        {
            // 获取正交相机
            _orthoMainCamera = Camera.main;
            _orthoCameraBrain = _orthoMainCamera?.GetComponent<CinemachineBrain>();
            _curCameraEnum = CameraEnum.Default;
        }

        #region 相机信息注册

        public void RegisterUICamera(Camera overlayCamera)
        {
            var mainCameraData = _orthoMainCamera.GetUniversalAdditionalCameraData();
        
            if (mainCameraData != null)
            {
                if (!mainCameraData.cameraStack.Contains(overlayCamera))
                {
                    mainCameraData.cameraStack.Insert(0, overlayCamera);
                }
            }
            else
            {
                Debug.LogError("Main Camera does not have UniversalAdditionalCameraData.");
            }
        }

        public void UnRegisterUICamera(Camera overlayCamera)
        {
            // 获取 Main Camera 的 UniversalAdditionalCameraData
            var mainCameraData = _orthoMainCamera.GetUniversalAdditionalCameraData();

            if (mainCameraData != null)
            {
                // 检查 Overlay Camera 是否在 Stack 中
                if (mainCameraData.cameraStack.Contains(overlayCamera))
                {
                    // 将 Overlay Camera 从 Stack 移除
                    mainCameraData.cameraStack.Remove(overlayCamera);
                    Debug.Log("Overlay Camera removed from Main Camera stack.");
                }
            }
            else
            {
                Debug.LogError("Main Camera does not have UniversalAdditionalCameraData.");
            }
        }
        
        public void RegisterCamera(CameraEnum camType, ICinemachineCamera virtualCamera)
        {
            _virtualCameraDict[camType] = virtualCamera;

            var vcam = virtualCamera.VirtualCameraGameObject.GetComponent<CinemachineVirtualCamera>();
            if (vcam == null)
            {
                Debug.LogWarning($"RegisterCamera: {camType} 的 GameObject 上未找到 CinemachineVirtualCamera 组件");
                return;
            }

            var initState = new CamState
            {
                pos = virtualCamera.VirtualCameraGameObject.transform.localPosition,
                initOrthoSize = vcam.m_Lens.OrthographicSize
            };
            _camInitStateDict[camType] = initState;
        }

        public void UnRegisterCamera(CameraEnum camType)
        {
            _virtualCameraDict.Remove(camType);
            _camInitStateDict.Remove(camType);
        }

        public void RemoveAllCam()
        {
            _virtualCameraDict.Clear();
            _camInitStateDict.Clear();
        }

        #endregion

        /// <summary>
        /// 检查当前是否需要切相机
        /// </summary>
        /// <param name="targetCameraState"></param>
        /// <returns>是就不用切相机</returns>
        public bool EqualToCameraState(CameraEnum targetCameraState)
        {
            return _curCameraEnum == targetCameraState;
        }

        /// <summary>
        /// 切换相机
        /// </summary>
        /// <param name="camType">目标相机</param>
        /// <param name="immediate">true 则跳过过渡动画立即切换（适用于读档等场景）</param>
        public IEnumerator SwitchCamera(CameraEnum camType, bool immediate = false)
        {
            var switchDuration = SwitchCameraSync(camType, immediate);
            if (switchDuration > 0f)
            {
                yield return new WaitForSeconds(switchDuration);
            }
            else
            {
                // 至少等待两帧，确保相机切换完成
                yield return null;
                yield return null;
            }
        }

        private float SwitchCameraSync(CameraEnum camType, bool immediate = false)
        {
            if (_curCameraEnum == camType)
            {
                return 0;
            }

            if (!_virtualCameraDict.ContainsKey(camType))
            {
                Debug.LogWarning($"SwitchCamera: {camType} 相机未注册");
                return 0;
            }

            var activeBrain = _orthoCameraBrain;

            CinemachineBlendDefinition originalBlend = default;
            if (immediate)
            {
                originalBlend = activeBrain.m_DefaultBlend;
                activeBrain.m_DefaultBlend = new CinemachineBlendDefinition(
                    CinemachineBlendDefinition.Style.Cut, 0f);
            }

            _virtualCameraDict.TryGetValue(_curCameraEnum, out var fromVCam);
            var toVCam = _virtualCameraDict[camType];

            // 设置虚拟相机优先级
            foreach (var camPair in _virtualCameraDict)
            {
                camPair.Value.Priority = camPair.Key == camType ? HighPriority : LowPriority;
            }

            _curInitState = _camInitStateDict[camType];
            var lastCamEnum = _curCameraEnum;
            _curCameraEnum = camType;

            if (immediate)
            {
                ResetVirCam(lastCamEnum);
                var blend = originalBlend;
                ActionKit.Delay(0f, () => activeBrain.m_DefaultBlend = blend).StartGlobal();
                return 0f;
            }

            // CinemachineBrain.LookupBlend 在 2.x 中是 private，这里重写其等价逻辑：
            // Custom Blends 资产里有匹配项就用它，否则回退到 Default Blend。
            var blendTime = ResolveBlendTime(activeBrain, fromVCam, toVCam);
            ActionKit.Delay(blendTime, () => ResetVirCam(lastCamEnum)).StartGlobal();

            return blendTime;
        }

        private static float ResolveBlendTime(
            CinemachineBrain brain,
            ICinemachineCamera fromCam,
            ICinemachineCamera toCam)
        {
            var blend = brain.m_DefaultBlend;

            if (brain.m_CustomBlends != null)
            {
                var fromName = fromCam != null ? fromCam.Name : string.Empty;
                var toName = toCam != null ? toCam.Name : string.Empty;
                blend = brain.m_CustomBlends.GetBlendForVirtualCameras(fromName, toName, blend);
            }

            if (CinemachineCore.GetBlendOverride != null)
            {
                blend = CinemachineCore.GetBlendOverride(fromCam, toCam, blend, brain);
            }

            return blend.BlendTime;
        }

        public void ResetCamera()
        {
            _curCameraEnum = CameraEnum.Default;
            RemoveAllCam();
        }

        private void ResetVirCam(CameraEnum cameraEnum)
        {
            if (cameraEnum == CameraEnum.Default)
            {
                return;
            }

            if (!_virtualCameraDict.TryGetValue(cameraEnum, out var virCam))
            {
                return;
            }
            
            var camState = _camInitStateDict[cameraEnum];
            virCam.VirtualCameraGameObject.transform.localPosition = camState.pos;
            var camObj = virCam.VirtualCameraGameObject.GetComponent<CinemachineVirtualCamera>();
            camObj.m_Lens.OrthographicSize = camState.initOrthoSize;
        }

        private Tween TransCamera(Vector3 targetPos, float targetOrthographicSize, float duration)
        {
            // 寻找现在正在激活的相机
            if (_orthoCameraBrain == null)
            {
                Debug.LogWarning("TransCamera: CinemachineBrain is null.");
                return null;
            }
            var curCamera = _orthoCameraBrain.ActiveVirtualCamera;
            if (curCamera == null)
            {
                Debug.LogWarning("TransCamera: No active virtual camera found.");
                return null;
            }

            var sq = DOTween.Sequence();
            // 移动
            sq.Join(curCamera.DOLocalMove(targetPos, duration));
            // 缩放
            sq.Join(curCamera.DOOrthoSize(targetOrthographicSize, duration));

            return sq;
        }

        private Tween ReturnInitCamera(float duration)
        {
            return TransCamera(_curInitState.pos, _curInitState.initOrthoSize, duration);
        }

        public IEnumerator TransCameraAsync(Vector3 targetPos, float targetOrthographicSize, float duration)
        {
            var tween = TransCamera(targetPos, targetOrthographicSize, duration);
            if (tween != null)
            {
                yield return tween.WaitForCompletion();
            }
        }

        public IEnumerator ReturnInitCameraAsync(float duration)
        {
            var tween = ReturnInitCamera(duration);
            if (tween != null)
            {
                yield return tween.WaitForCompletion();
            }
        }

        public IEnumerator ShakeCamera(float duration, float strength, int vibrate)
        {
            if (_orthoCameraBrain == null)
            {
                Debug.LogWarning("ShakeCamera: CinemachineBrain is null.");
                yield break;
            }
            var curCamera = _orthoCameraBrain.ActiveVirtualCamera;
            if (curCamera == null)
            {
                Debug.LogWarning("ShakeCamera: No active virtual camera found.");
                yield break;
            }

            var transform = curCamera.VirtualCameraGameObject.transform;

            // 停止并清理之前的震动，防止多个 tween 叠加导致无法回归原点
            if (_shakeTween != null && _shakeTween.IsActive())
            {
                _shakeTween.Kill();
                if (_camInitStateDict.TryGetValue(_curCameraEnum, out var camState))
                {
                    transform.localPosition = camState.pos;
                }
            }

            _shakeTween = transform
                .DOShakePosition(duration, strength, vibrate, 90, false, false)
                .OnComplete(() => _shakeTween = null);

            yield return _shakeTween.WaitForCompletion();
        }

        /// <summary>
        /// 获取当前激活的相机
        /// </summary>  
        public Camera GetCurrentCamera()
        {
            return _orthoMainCamera;
        }

        /// <summary>
        /// 获取鼠标在世界中的位置
        /// </summary>
        /// <param name="mousePoint">鼠标界面位置</param>
        /// <returns>世界位置</returns>
        public static Vector3 GetMouseWorldPos(Vector3 mousePoint)
        {
            var cam = Instance._orthoMainCamera;
            if (cam == null) return Vector3.zero;

            var pos = cam.ScreenToWorldPoint(mousePoint);
            return new Vector3(pos.x, pos.y, 0);
        }

        public static Vector3 GetScreenPos(Vector3 worldPos)
        {
            var cam = Instance._orthoMainCamera;
            if (cam == null) return Vector3.zero;

            worldPos.z = 0;
            return cam.WorldToScreenPoint(worldPos);
        }
    }

    public static class CinemachineExtension
    {
        public static TweenerCore<Vector3, Vector3, VectorOptions> DOLocalMove(this ICinemachineCamera camera,
            Vector3 targetPos, float duration)
        {
            var transform = camera.VirtualCameraGameObject.gameObject.transform;
            return transform.DOLocalMove(targetPos, duration);
        }

        public static TweenerCore<float, float, FloatOptions> DOOrthoSize(this ICinemachineCamera camera,
            float endValue, float duration)
        {
            var virtualCamera = camera.VirtualCameraGameObject.GetComponent<CinemachineVirtualCamera>();
            var currentOrthoSize = virtualCamera.m_Lens.OrthographicSize;
            return DOTween.To(() => currentOrthoSize, x => currentOrthoSize = x, endValue, duration)
                .OnUpdate(() => virtualCamera.m_Lens.OrthographicSize = currentOrthoSize);
        }
        
    }

    public static class CameraCommand
    {
        [YarnCommand("return_init_camera")]
        public static IEnumerator ReturnInitCamera(float duration = 1f)
        {
            return CameraKit.Instance.ReturnInitCameraAsync(duration);
        }

        [YarnCommand("trans_camera")]
        public static IEnumerator TransCameraAsync(float x, float y, float targetOrthographicSize, float duration)
        {
            float z = CameraKit.Instance.GetCurrentCamera()?.transform.position.z ?? -10f;
            Vector3 targetPos = new Vector3(x, y, z);
            return CameraKit.Instance.TransCameraAsync(targetPos, targetOrthographicSize, duration);
        }

        [YarnCommand("shake_camera")]
        public static IEnumerator ShakeCamera(float duration, float strength, int vibrate = 10)
        {
            return CameraKit.Instance.ShakeCamera(duration, strength, vibrate);
        }

        [YarnCommand("switch_camera")]
        public static IEnumerator SwitchCamera(string targetStateStr, bool immediate = false)
        {
            if (!Enum.TryParse<CameraEnum>(targetStateStr, out var targetState))
            {
                Debug.LogWarning($"SwitchCamera: \"{targetStateStr}\" 不在 CameraEnum 枚举中");
                yield break;
            }

            yield return CameraKit.Instance.SwitchCamera(targetState, immediate);
        }
    }

    public enum CameraEnum
    {
        Default,
        Clinic,
        CoolingMachine,
        BodyModule,
        BodyModuleCenter,
        Memory,
        Logic,
        Eye,
        UF,
        Expression,
        EyeDeep,
        ExpressionDeep,
        Emo,
        EmoDeep,
        Op,
        CutEmo,
        CutMemory,
        CutLogic,
        CutEmoDeep,
        CutMemoryDeep,
        CutLogicDeep,
        BreakCamera,
        DreamCamera,
        Subway,
        SubwayTV,
        Language,
        LanguageDeep,
        AnalysisMode,
        AnalysisModeDeep,
        SaleCamera,
        SaleDeepCamera
    }
}