using System;
using System.Collections.Generic;
using DG.Tweening;
using SickscoreGames.HUDNavigationSystem;
using UniRx;
using UnityEngine;
using UnityEngine.UI;
using SLSUtilities.General;
using Unity.Cinemachine;
using Ease = DG.Tweening.Ease;

namespace Cielonos.MainGame.Characters
{
    public partial class LockTargetSubmodule : SubmoduleBase<PlayerViewSubcontroller>
    {
        private Player player => owner.player;
        private PlayerViewSubcontroller viewSc => owner;
        private PlayerInputSubcontroller inputSc => player.inputSc;
        private HUDNavigationSystem navigationSystem => HUDNavigationSystem.Instance;
        private HUDNavigationCanvas navigationCanvas => HUDNavigationCanvas.Instance;
        
        /// <summary>
        /// 通常ACT类武器锁定目标时自动旋转摄像机，即使用LockTargetCamera
        /// TPS类远程武器不自动旋转，仅在目标上显示锁定标记，不切换摄像机
        /// </summary>
        public bool isAutoRotate;
        /// <summary>
        /// 是否正在锁定目标
        /// </summary>
        public bool isLocking;
        /// <summary>
        /// 是否正在使用锁定目标摄像机
        /// </summary>
        public bool isUsingLockTargetCamera => isLocking && isAutoRotate;
        
        public bool isDuringCameraSwitch;
        private const float CameraSwitchCooldown = 0.5f;
        
        public Enemy lockTarget;
        private float lastTargetSwitchTime;
        private const float TargetSwitchCooldown = 0.5f;
        public Transform targetPoint;
        
        // 用于存储独立的摄像机平滑旋转状态，防止跟随 Transform 的跳变
        private float currentYaw;
        private float currentPitch;
        
        private Tweener iconTween;
        
        public LockTargetSubmodule(PlayerViewSubcontroller owner) : base(owner)
        {
            isLocking = false;
            isAutoRotate = false;
            isDuringCameraSwitch = false;
            lockTarget = null;
            targetPoint = null;
        }

        public void Update()
        {
            if (isUsingLockTargetCamera)
            {
                if (targetPoint != null)
                {
                    Vector3 actualTargetPos = targetPoint.position;
                    Vector3 playerPos = viewSc.cameraRoot.position;
                    var camLockData = viewSc.currentCameraLockData;

                    // 1. 根据距离动态计算怪物权重
                    float horizontalDistance = Vector2.Distance(new Vector2(playerPos.x, playerPos.z), new Vector2(actualTargetPos.x, actualTargetPos.z));
                    float closeRangeThreshold = camLockData.weightDistanceRange.x;
                    float farRangeThreshold = camLockData.weightDistanceRange.y;
                    float dynamicWeight = camLockData.weightCurve.Evaluate((horizontalDistance - closeRangeThreshold) / (farRangeThreshold - closeRangeThreshold));

                    // 2. 高度差硬性限制 (解决 Boss 跳跃问题)
                    float heightDiff = actualTargetPos.y - playerPos.y;
                    float maxHeightDifference = 2f; 
                    if (heightDiff > maxHeightDifference)
                    {
                        // 确保 TargetGroup 中心点的 Y 坐标最高不超过 player.y + maxHeightDifference
                        float heightWeightLimit = maxHeightDifference / (heightDiff - maxHeightDifference);
                        dynamicWeight = Mathf.Min(dynamicWeight, heightWeightLimit);
                    }

                    // 3. 将动态权重应用到 TargetGroup 中的目标
                    List<CinemachineTargetGroup.Target> targets = viewSc.targetGroup.Targets;
                    targets[0].Weight = 1 - dynamicWeight; //玩家中心点权重
                    for (int i = 1; i < targets.Count; i++)
                    {
                        if (targets[i].Object == targetPoint)
                        {
                            var t = targets[i];
                            t.Weight = dynamicWeight;
                            targets[i] = t;
                            break;
                        }
                    }

                    // 4. 重新计算虚拟中心点，用于驱动 OrbitalFollow 的轨道 Pitch
                    // 注意：Yaw 依旧严格瞄准敌人的真实 XZ 位置，以免水平方向跑偏
                    Vector3 horizontalDirection = actualTargetPos - playerPos;
                    float targetYaw = Mathf.Atan2(horizontalDirection.x, horizontalDirection.z) * Mathf.Rad2Deg;

                    float groupCenterY = (playerPos.y * 1f + actualTargetPos.y * dynamicWeight) / (1f + dynamicWeight);
                    float virtualYDiff = groupCenterY - playerPos.y;
                    float targetPitch = Mathf.Atan2(-virtualYDiff, horizontalDistance) * Mathf.Rad2Deg;

                    // 独立平滑 Yaw (保证在水平面上环绕旋转) 和 Pitch，使用内部状态而非容易受动画影响的 transform
                    float smoothFactor = 1f - Mathf.Exp(-10f * Time.deltaTime);
                    currentYaw = Mathf.LerpAngle(currentYaw, targetYaw, smoothFactor);
                    currentPitch = Mathf.LerpAngle(currentPitch, targetPitch, smoothFactor);
                    
                    // 限制硬锁定时的最大俯仰角，防止在极近距离或穿模时摄像机垂直朝地/朝天
                    currentPitch = Mathf.Clamp(currentPitch, -20f, 60f);

                    viewSc.cameraRoot.rotation = Quaternion.Euler(currentPitch, currentYaw, 0f);
                    
                    // 【2】接管并强制控制 OrbitalFollow 的轨道位置
                    var orbitalFollow = viewSc.lockingTargetCamera.GetComponent<CinemachineOrbitalFollow>();
                    // 直接强制摄像机在水平和垂直轨道上移动
                    orbitalFollow.HorizontalAxis.Value = currentYaw;
                    orbitalFollow.VerticalAxis.Value = currentPitch;
                    
                    float OF_Fade = camLockData.orbitalFollowFadeCurve.Evaluate(Mathf.Clamp01((horizontalDistance - camLockData.orbitalFollowFadeDistanceRange.x) / 
                                                                                              (camLockData.orbitalFollowFadeDistanceRange.y - camLockData.orbitalFollowFadeDistanceRange.x)));
                    orbitalFollow.TargetOffset.y = MathExtensions.Lerp(camLockData.orbitalFollowTargetYRange, OF_Fade);
                    
                    var rotationComposer = viewSc.lockingTargetCamera.GetComponent<CinemachineRotationComposer>();
                    float RC_Fade = camLockData.rotationComposerFadeCurve.Evaluate(Mathf.Clamp01((horizontalDistance - camLockData.rotationComposerFadeDistanceRange.x) / 
                                                                                              (camLockData.rotationComposerFadeDistanceRange.y - camLockData.rotationComposerFadeDistanceRange.x)));
                    rotationComposer.TargetOffset.y = MathExtensions.Lerp(camLockData.rotationComposerTargetYRange, RC_Fade);
                }
            }
        }
    }
    
    public partial class LockTargetSubmodule
    {
        public void SwitchLockState()
        {
            if (isLocking)
            {
                UnlockTarget();
            }
            else
            {
                LockTarget(true);
            }
        }
        
        public void LockTarget(bool isAutoRotate)
        {
            if(isDuringCameraSwitch) return;
            
            Enemy target = CombatManager.EnemySm.GetNearestEnemy(50f);
            
            if (target != null)
            {
                this.isLocking = true;
                this.isAutoRotate = isAutoRotate;
                this.lockTarget = target;
                this.isDuringCameraSwitch = true;
                
                // 初始化内部旋转状态，防止切入时画面突变
                Vector3 camEuler = viewSc.playerCamera.transform.eulerAngles;
                currentYaw = camEuler.y;
                currentPitch = camEuler.x;
                if (currentPitch > 180f) currentPitch -= 360f;
                
                if (isAutoRotate)
                {
                    targetPoint = target.bodyPartsSc.cameraLockingPoint ?? target.bodyPartsSc.staticCenterPoint;
                    // 给怪物赋予基础权重 1，以及 1.5 的包围盒半径，防止 Group size is zero
                    viewSc.targetGroup.AddMember(targetPoint, 1f, 1.5f);
                    viewSc.currentCamera = viewSc.lockingTargetCamera;
                    viewSc.lockingTargetCamera.LookAt = viewSc.targetGroup.transform;
                    viewSc.stateDrivenCamera.GetComponent<Animator>().SetBool("isLockTarget", true);
                    
                    Observable.Timer(TimeSpan.FromSeconds(CameraSwitchCooldown)).First().Subscribe(_ =>
                    {
                        isDuringCameraSwitch = false; 
                    });
                }
                else
                {
                    Observable.Timer(TimeSpan.FromSeconds(CameraSwitchCooldown)).First().Subscribe(_ =>
                    {
                        isDuringCameraSwitch = false;
                    });
                }

                lockTarget.navigationElement.showIndicator = true;
                Image icon = lockTarget.navigationElement.Indicator.OnscreenIcon;
                iconTween?.Kill(true);
                iconTween = icon.GetComponent<RectTransform>().DOScale(1f, 0.5f).From(0f).SetEase(Ease.OutQuart).Play();
            }
        }

        public void UnlockTarget()
        {
            if(isDuringCameraSwitch) return;
            
            Vector3 currentEuler = viewSc.playerCamera.transform.rotation.eulerAngles;
            
            var inputController = viewSc.freeLookCamera.GetComponent<CinemachineInputAxisController>();
            if (inputController == null) return;
            
            float newYaw = currentEuler.y;
            float newPitch = currentEuler.x;
            if (newPitch > 180f) newPitch -= 360f;
            
            float minPitch = -20f; 
            float maxPitch = 70f;
            
            newPitch = Mathf.Clamp(newPitch, minPitch, maxPitch);

            CinemachineOrbitalFollow orbitalFollow = viewSc.freeLookCamera.GetComponent<CinemachineOrbitalFollow>();
            orbitalFollow.HorizontalAxis.Value = newYaw;
            orbitalFollow.VerticalAxis.Value = newPitch;
            
            if (lockTarget != null)
            {
                lockTarget.navigationElement.showIndicator = false;
            }
            
            this.isLocking = false;
            this.isAutoRotate = false;
            viewSc.stateDrivenCamera.GetComponent<Animator>().SetBool("isLockTarget", false);
            
            Transform oldTargetPoint = targetPoint;
            this.lockTarget = null;
            this.targetPoint = null;
            this.isDuringCameraSwitch = true;
            
            // 延迟移除目标组的成员，直到摄像机混合完成（通常为 0.5s）。
            // 否则退出的相机在混合的第一帧就会因为失去目标而瞬间位移，导致画面抖动。
            Observable.Timer(TimeSpan.FromSeconds(CameraSwitchCooldown)).First().Subscribe(_ =>
            {
                if (oldTargetPoint != null)
                {
                    viewSc.targetGroup.RemoveMember(oldTargetPoint);
                }
                isDuringCameraSwitch = false;
            });
        }
        
        /// <summary>
        /// 切换锁定目标
        /// </summary>
        public void SwitchTarget(float direction)
        {
            if (!isLocking || isDuringCameraSwitch) return;
            
            if (Time.time - lastTargetSwitchTime < TargetSwitchCooldown) return;
            
            List<Enemy> sortedEnemies = CombatManager.EnemySm.GetVisibleEnemiesSortedByScreenX();
            if (sortedEnemies.Count <= 1) return;
    
            int currentIndex = sortedEnemies.IndexOf(lockTarget);
            if (currentIndex < 0)
            {
                currentIndex = 0;
            }

            int dir = direction > 0 ? -1 : 1;
            int newIndex = currentIndex + dir;
    
            // 边界检查（无循环）
            if (newIndex < 0 || newIndex >= sortedEnemies.Count)
            {
                return;
            }
    
            CharacterBase newTarget = sortedEnemies[newIndex];
    
            // 目标相同检查
            if (newTarget == lockTarget)
            {
                return;
            }
            
            lastTargetSwitchTime = Time.time;
            SetNewTarget(sortedEnemies[newIndex]);
        }
        
        private void SetNewTarget(Enemy newTarget)
        {
            if (lockTarget != null)
            {
                lockTarget.navigationElement.showIndicator = false;
            }
            
            lockTarget = newTarget;
            Transform oldTargetPoint = targetPoint;
            targetPoint = newTarget.bodyPartsSc.cameraLockingPoint ?? newTarget.bodyPartsSc.staticCenterPoint;
            
            if (isUsingLockTargetCamera)
            {
                viewSc.lockingTargetCamera.LookAt = viewSc.targetGroup.transform;
                
                // 同步更新 TargetGroup，替换新旧目标点
                if (oldTargetPoint != null && oldTargetPoint != targetPoint)
                {
                    viewSc.targetGroup.RemoveMember(oldTargetPoint);
                }
                viewSc.targetGroup.AddMember(targetPoint, 1f, 1.5f);
            }
            
            lockTarget.navigationElement.showIndicator = true;
            Image icon = lockTarget.navigationElement.Indicator.OnscreenIcon;
            iconTween?.Kill(true);
            iconTween = icon.GetComponent<RectTransform>().DOScale(1f, 0.3f).From(0.5f).SetEase(Ease.OutQuart).Play();
        }
    }
}