using System.Collections;
using UnityEngine;
using UnityEngine.Events;

public class ClamOpenClose : MonoBehaviour
{
    [Header("Shell Hinges")]
    [SerializeField] private Transform upShell;
    [SerializeField] private Transform downShell;

    [Header("Open Angle")]
    [Tooltip("X축 기준으로 얼마나 열릴지 설정합니다. 음수값이 커질수록 더 많이 열립니다.")]
    [SerializeField] private float upShellOpenX = -45f;

    [Tooltip("아래 조개도 함께 움직일 경우 사용합니다. 필요 없으면 0으로 두세요.")]
    [SerializeField] private float downShellOpenX = 0f;

    [Header("Timing")]
    [SerializeField] private float minClosedTime = 0.6f;
    [SerializeField] private float maxClosedTime = 1.8f;

    [SerializeField] private float minOpenTime = 0.8f;
    [SerializeField] private float maxOpenTime = 2.0f;

    [SerializeField] private float openDuration = 1.5f;
    [SerializeField] private float closeDuration = 0.2f;

    [Header("Motion")]
    [SerializeField] private AnimationCurve openCurve = AnimationCurve.EaseInOut(0, 0, 1, 1);
    [SerializeField] private AnimationCurve closeCurve = AnimationCurve.EaseInOut(0, 0, 1, 1);

    [Header("Snap Close Effect")]
    [SerializeField] private bool useSnapClose = true;

    [Tooltip("닫힐 때 살짝 더 닫히는 오버슈트 각도입니다.")]
    [SerializeField] private float snapCloseOvershootX = 3f;

    [Tooltip("쾅 하고 닫힌 뒤 원래 닫힌 위치로 돌아오는 시간입니다.")]
    [SerializeField] private float snapCloseOvershootDuration = 0.02f;

    [Header("Start Option")]
    [SerializeField] private bool startAutomatically = true;
    [SerializeField] private bool startOpened = false;

    [Header("Events")]
    public UnityEvent onOpened;
    public UnityEvent onCloseStarted;
    public UnityEvent onClosed;

    private Quaternion upClosedRot;
    private Quaternion downClosedRot;

    private Quaternion upOpenedRot;
    private Quaternion downOpenedRot;

    private Coroutine routine;
    private bool isOpen;
    private bool isClosing;

    public bool IsOpen => isOpen;
    public bool IsClosing => isClosing;

    private void Awake()
    {
        if (upShell == null)
        {
            Transform found = transform.Find("Scale/UpShell");
            if (found != null) upShell = found;
        }

        if (downShell == null)
        {
            Transform found = transform.Find("Scale/DownShell");
            if (found != null) downShell = found;
        }

        if (upShell == null)
        {
            Debug.LogWarning("[ClamOpenClose] UpShell이 연결되지 않았습니다.", this);
            return;
        }

        upClosedRot = upShell.localRotation;

        if (downShell != null)
            downClosedRot = downShell.localRotation;

        upOpenedRot = upClosedRot * Quaternion.Euler(upShellOpenX, 0f, 0f);

        if (downShell != null)
            downOpenedRot = downClosedRot * Quaternion.Euler(downShellOpenX, 0f, 0f);
    }

    private void Start()
    {
        if (startOpened)
            SetOpenedImmediately();
        else
            SetClosedImmediately();

        if (startAutomatically)
            StartClam();
    }

    public void StartClam()
    {
        if (routine != null)
            StopCoroutine(routine);

        routine = StartCoroutine(OpenCloseRoutine());
    }

    public void StopClam()
    {
        if (routine != null)
        {
            StopCoroutine(routine);
            routine = null;
        }
    }

    private IEnumerator OpenCloseRoutine()
    {
        while (true)
        {
            float closedWait = Random.Range(minClosedTime, maxClosedTime);
            yield return new WaitForSeconds(closedWait);

            isClosing = false;

            yield return MoveShells(
                upClosedRot,
                upOpenedRot,
                downClosedRot,
                downOpenedRot,
                openDuration,
                openCurve
            );

            isOpen = true;
            isClosing = false;
            onOpened?.Invoke();

            float openWait = Random.Range(minOpenTime, maxOpenTime);
            yield return new WaitForSeconds(openWait);

            isClosing = true;
            onCloseStarted?.Invoke();

            yield return MoveShells(
                upOpenedRot,
                upClosedRot,
                downOpenedRot,
                downClosedRot,
                closeDuration,
                closeCurve
            );

            isOpen = false;

            if (useSnapClose)
            {
                yield return SnapCloseEffect();
            }

            isClosing = false;
            onClosed?.Invoke();
        }
    }

    private IEnumerator MoveShells(
        Quaternion upFrom,
        Quaternion upTo,
        Quaternion downFrom,
        Quaternion downTo,
        float duration,
        AnimationCurve curve)
    {
        float timer = 0f;

        while (timer < duration)
        {
            timer += Time.deltaTime;

            float t = Mathf.Clamp01(timer / duration);
            float curvedT = curve.Evaluate(t);

            if (upShell != null)
                upShell.localRotation = Quaternion.Slerp(upFrom, upTo, curvedT);

            if (downShell != null)
                downShell.localRotation = Quaternion.Slerp(downFrom, downTo, curvedT);

            yield return null;
        }

        if (upShell != null)
            upShell.localRotation = upTo;

        if (downShell != null)
            downShell.localRotation = downTo;
    }

    private IEnumerator SnapCloseEffect()
    {
        Quaternion upSnapRot = upClosedRot * Quaternion.Euler(snapCloseOvershootX, 0f, 0f);

        Quaternion downSnapRot = downClosedRot;

        if (downShell != null)
            downSnapRot = downClosedRot * Quaternion.Euler(-snapCloseOvershootX * 0.3f, 0f, 0f);

        if (upShell != null)
            upShell.localRotation = upSnapRot;

        if (downShell != null)
            downShell.localRotation = downSnapRot;

        yield return new WaitForSeconds(snapCloseOvershootDuration);

        if (upShell != null)
            upShell.localRotation = upClosedRot;

        if (downShell != null)
            downShell.localRotation = downClosedRot;
    }

    private void SetClosedImmediately()
    {
        if (upShell != null)
            upShell.localRotation = upClosedRot;

        if (downShell != null)
            downShell.localRotation = downClosedRot;

        isOpen = false;
        isClosing = false;
    }

    private void SetOpenedImmediately()
    {
        if (upShell != null)
            upShell.localRotation = upOpenedRot;

        if (downShell != null)
            downShell.localRotation = downOpenedRot;

        isOpen = true;
        isClosing = false;
    }
}