using System.Collections;
using System.IO;
using UnityEngine;
using Core.InputLock;
using UnityEngine.Events;
#if DOTWEEN
using DG.Tweening;
#endif

namespace OpeningSystem
{
    public class AwakeningSequenceController : MonoBehaviour
    {
        [Header("Trigger Conditions")]
        [Tooltip("如果为 true，则仅在没有存档文件时（即新游戏/重新开始）才会播放此动画")]
        public bool onlyPlayOnNewGame = true;

        [Header("UI Fader")]
        [Tooltip("拖入一个全屏纯黑 Image 的 CanvasGroup")]
        public CanvasGroup blackScreenCanvasGroup;
        
        [Header("Sequence Timing")]
        public float initialBlackDuration = 2f;
        public float fadeFromBlackDuration = 3f;
        public float cameraLookUpDuration = 4f;

        [Header("Look Staging")]
        [Range(0f, 1f)] public float lookMidProgress01 = 0.5f;
        public float lookMidPauseDuration = 0.25f;

        [Header("Player & Camera References")]
        public Transform playerBody;
        public Transform playerCameraPivot;
        
        [Header("Target Positions & Angles")]
        [Tooltip("主角醒来时的初始位置与朝向标记（如果为空则在主角原位置醒来）")]
        public Transform startPlayerTransform;
        [Tooltip("相机初始俯视角度（正数表示低头看地，例如 60f）")]
        public float cameraStartDownAngle = 60f;

        [Header("Events")]
        [SerializeField] private UnityEvent onAwakeningFinished = new UnityEvent();
        [SerializeField] private bool invokeFinishedWhenSkipped = false;

#if DOTWEEN
        [Header("DOTween")]
        public bool useUnscaledTime = false;
        public Ease fadeFromBlackEase = Ease.InOutSine;
        public Ease lookEase = Ease.InOutSine;
#endif

        private void Start()
        {
            if (onlyPlayOnNewGame)
            {
                string savePath = Path.Combine(Application.persistentDataPath, "savegame.json");
                if (File.Exists(savePath))
                {
                    // 这是一个"继续游戏"的情况，不播放苏醒动画
                    if (blackScreenCanvasGroup != null)
                    {
                        blackScreenCanvasGroup.alpha = 0f;
                        blackScreenCanvasGroup.gameObject.SetActive(false);
                    }
                    if (invokeFinishedWhenSkipped) { onAwakeningFinished.Invoke(); }
                    return;
                }
            }

            StartAwakeningSequence();
        }

        public void StartAwakeningSequence()
        {
#if DOTWEEN
            PlaySequenceWithDOTween();
#else
            StartCoroutine(AwakeningCoroutine());
#endif
        }

#if DOTWEEN
        private void PlaySequenceWithDOTween()
        {
            if (PlayerControlLockService.Instance != null)
            {
                PlayerControlLockService.Instance.Lock(this);
            }

            if (blackScreenCanvasGroup == null)
            {
                Debug.LogWarning("[AwakeningSequenceController] Black Screen CanvasGroup 未指定!");
                UnlockPlayer();
                return;
            }

            // 初始化状态：纯黑、相机低头、传送玩家
            blackScreenCanvasGroup.gameObject.SetActive(true);
            blackScreenCanvasGroup.alpha = 1f;
            ApplyStartPositionAndReset();

            Sequence sequence = DOTween.Sequence();
            sequence.SetUpdate(useUnscaledTime);

            // 1. 保持黑屏一段时间（昏迷中）
            sequence.AppendInterval(initialBlackDuration);

            // 2. 视野逐渐变亮（睁眼）
            Tween fadeFromTween = blackScreenCanvasGroup.DOFade(0f, Mathf.Max(0.0001f, fadeFromBlackDuration)).SetEase(fadeFromBlackEase);
            sequence.Append(fadeFromTween);

            // 3. 镜头慢慢抬起（站起/抬头）
            if (playerCameraPivot != null)
            {
                float mid01 = Mathf.Clamp01(lookMidProgress01);
                float firstDuration = Mathf.Max(0.0001f, cameraLookUpDuration * mid01);
                float secondDuration = Mathf.Max(0.0001f, cameraLookUpDuration * (1f - mid01));
                float midAngle = Mathf.Lerp(cameraStartDownAngle, 0f, mid01);

                Sequence lookSequence = DOTween.Sequence();
                lookSequence.SetUpdate(useUnscaledTime);
                lookSequence.Append(playerCameraPivot.DOLocalRotate(new Vector3(midAngle, 0f, 0f), firstDuration, RotateMode.Fast).SetEase(lookEase));
                if (lookMidPauseDuration > 0f) lookSequence.AppendInterval(lookMidPauseDuration);
                lookSequence.Append(playerCameraPivot.DOLocalRotate(Vector3.zero, secondDuration, RotateMode.Fast).SetEase(lookEase));

                sequence.Join(lookSequence);
            }

            // 4. 动画结束，解除锁定并隐藏黑屏UI
            sequence.AppendCallback(() => 
            {
                blackScreenCanvasGroup.gameObject.SetActive(false);
                UnlockPlayer();
                onAwakeningFinished.Invoke();
            });
        }
#endif

        private IEnumerator AwakeningCoroutine()
        {
            if (PlayerControlLockService.Instance != null)
            {
                PlayerControlLockService.Instance.Lock(this);
            }

            if (blackScreenCanvasGroup == null)
            {
                Debug.LogWarning("[AwakeningSequenceController] Black Screen CanvasGroup 未指定!");
                UnlockPlayer();
                yield break;
            }

            // 初始化状态：纯黑、相机低头、传送玩家
            blackScreenCanvasGroup.gameObject.SetActive(true);
            blackScreenCanvasGroup.alpha = 1f;
            ApplyStartPositionAndReset();

            // 1. 保持黑屏一段时间（昏迷中）
            yield return new WaitForSeconds(initialBlackDuration);

            // 2 & 3. 视野逐渐变亮并伴随镜头抬起
            Coroutine fadeRoutine = StartCoroutine(FadeScreen(1f, 0f, fadeFromBlackDuration, blackScreenCanvasGroup));
            Coroutine lookRoutine = StartCoroutine(LookUpCoroutine());
            
            yield return fadeRoutine;
            yield return lookRoutine;

            // 4. 动画结束，解除锁定并隐藏黑屏UI
            blackScreenCanvasGroup.gameObject.SetActive(false);
            UnlockPlayer();
            onAwakeningFinished.Invoke();
        }

        private void UnlockPlayer()
        {
            if (PlayerControlLockService.Instance != null)
            {
                PlayerControlLockService.Instance.Unlock(this);
            }
        }

        private void ApplyStartPositionAndReset()
        {
            if (playerBody != null && startPlayerTransform != null)
            {
                var cc = playerBody.GetComponent<CharacterController>();
                if (cc != null) cc.enabled = false;

                playerBody.position = startPlayerTransform.position;
                playerBody.rotation = startPlayerTransform.rotation;

                if (cc != null) cc.enabled = true;
            }

            if (playerCameraPivot != null)
            {
                playerCameraPivot.localRotation = Quaternion.Euler(cameraStartDownAngle, 0f, 0f);
            }
        }

        private IEnumerator LookUpCoroutine()
        {
            if (playerCameraPivot == null) yield break;

            float mid01 = Mathf.Clamp01(lookMidProgress01);
            float firstDuration = Mathf.Max(0.0001f, cameraLookUpDuration * mid01);
            float secondDuration = Mathf.Max(0.0001f, cameraLookUpDuration * (1f - mid01));

            Quaternion startRot = playerCameraPivot.localRotation;
            Quaternion midRot = Quaternion.Euler(Mathf.Lerp(cameraStartDownAngle, 0f, mid01), 0f, 0f);
            Quaternion endRot = Quaternion.identity;

            float t = 0f;
            while (t < 1f)
            {
                t += Time.deltaTime / firstDuration;
                playerCameraPivot.localRotation = Quaternion.Lerp(startRot, midRot, t);
                yield return null;
            }
            playerCameraPivot.localRotation = midRot;

            if (lookMidPauseDuration > 0f)
            {
                yield return new WaitForSeconds(lookMidPauseDuration);
            }

            t = 0f;
            while (t < 1f)
            {
                t += Time.deltaTime / secondDuration;
                playerCameraPivot.localRotation = Quaternion.Lerp(midRot, endRot, t);
                yield return null;
            }
            playerCameraPivot.localRotation = endRot;
        }

        private IEnumerator FadeScreen(float startAlpha, float endAlpha, float duration, CanvasGroup cg)
        {
            float t = 0f;
            while (t < 1f)
            {
                t += Time.deltaTime / duration;
                cg.alpha = Mathf.Lerp(startAlpha, endAlpha, t);
                yield return null;
            }
            cg.alpha = endAlpha;
        }
    }
}