using System.Collections.Generic;
using Superlazy;
using UnityEngine;

public interface IUnitAnimatorBinder
{
    void AddUpdate(IUnitViewUpdator updator);

    void RemoveUpdate(IUnitViewUpdator updator);

    bool UseAnimation { get; }
    bool RequireReset { get; }
    string Animation { get; }
    int CurrentFrame { get; }
    bool UseActionAnimationBegin { get; }
    float ActionAnimationBegin { get; }
    bool UseCrossFade { get; } // actionStop == false
    float CrossFade { get; }
    bool ActionStop { get; }
    bool Loop { get; }
}

public interface IUnitViewUpdator
{
    void OnUpdate();
}

public class UnitAnimatorController : MonoBehaviour, IUnitViewUpdator
{
    private static readonly float frameTime = 1.0f / 60.0f;
    private static readonly int[] animHashes = new int[] { Animator.StringToHash("Anim1"), Animator.StringToHash("Anim2") }; // Anim1, Anim2의 애니메이터 해시

    private IUnitAnimatorBinder unitView;

    private Animator animator;
    private AnimatorOverrideController overrideController;

    private int animatorFrame;
    private float animatorTime;
    private string currentAnim;

    private AnimationClip[] clips;

    private int animIndex = 0;
    private bool requireReset = false;

    private List<(Transform t, Vector3 p, Quaternion r, Vector3 s)> bindPoses;

    private void Awake() // TODO: 빌드시점으로 옮길수 있으면 좋음
    {
        animator = GetComponentInChildren<Animator>();
        animatorFrame = 0;
        currentAnim = null;
        animator.cullingMode = AnimatorCullingMode.AlwaysAnimate; // cullingMode가 걸려있는경우 꺼졌다가 켜진 상태에서 모든 동작이 X
        if (animator.runtimeAnimatorController == null)
        {
            overrideController = new AnimatorOverrideController(SLResources.GetAnimatorController("BaseController"));
            animator.runtimeAnimatorController = overrideController;

            clips = overrideController.animationClips;
        }

        if (bindPoses == null)
        {
            var allChildren = animator.GetComponentsInChildren<Transform>();
            bindPoses = new List<(Transform t, Vector3 p, Quaternion r, Vector3 s)>();
            foreach (var child in allChildren)
            {
                bindPoses.Add((child, child.localPosition, child.localRotation, child.localScale));
            }
        }
    }

    private void OnEnable()
    {
        unitView = GetComponentInParent<IUnitAnimatorBinder>();
        if (unitView == null) // Tool 등에서 유닛이 없는 경우 사용하지 않도록 설정
        {
            return;
        }

        unitView.AddUpdate(this);
    }

    private void ResetPose()
    {
        if (bindPoses == null) return;
        foreach (var (t, p, r, s) in bindPoses)
        {
            t.localPosition = p;
            t.localRotation = r;
            t.localScale = s;
        }
    }

    private bool UpdateCurrAnimation()
    {
        if (unitView.CurrentFrame - 1 - animatorFrame >= 0 && unitView.Animation == currentAnim) return false;

        ChangeController(unitView.Animation);
        currentAnim = unitView.Animation;

        return true;
    }

    private void ChangeController(string clipName)
    {
        var clip = SLResources.Load<AnimationClip>(clipName);
        if (clip == null)
        {
            SLLog.Error($"Can't Find: {clipName}.anim", this);
            return;
        }

        if (requireReset)
        {
            ResetPose();
        }

        requireReset = unitView.RequireReset;

        animIndex = (animIndex + 1) % 2;

        overrideController[clips[animIndex]] = clip;

        var startTime = 0.0f;
        if (unitView.UseActionAnimationBegin)
        {
            startTime = (unitView.ActionAnimationBegin - 1) / 60.0f;
        }

        var currentFrame = unitView.CurrentFrame - 1;
        startTime += currentFrame / 60.0f;

        if (currentAnim != null && unitView.UseCrossFade && unitView.ActionStop == false)
        {
            animator.CrossFadeInFixedTime(animHashes[animIndex], unitView.CrossFade, 0, startTime);
        }
        else
        {
            animator.PlayInFixedTime(animHashes[animIndex], 0, startTime);
        }

        animator.speed = 1;
        animator.Update(0.0f); // 업데이트를 돌때 속도가 0이면 시작 시간이 동작하지 않는다
        animator.speed = 0f;

        animatorFrame = currentFrame;
        animatorTime = currentFrame * frameTime;
    }

    private void UpdateAnimator()
    {
        var currentFrame = unitView.CurrentFrame - 1;
        var deltaFrame = currentFrame - animatorFrame;

        var deltaTime = Time.deltaTime;
        if (deltaFrame > 0 && Time.timeScale <= 0.01f)
        {
            animator.updateMode = AnimatorUpdateMode.UnscaledTime;
            deltaTime = Time.unscaledDeltaTime;
        }
        else
        {
            animator.updateMode = AnimatorUpdateMode.Normal;
        }

        if (deltaTime > 0.0000001f)
        {
            if (deltaFrame < 1)
            {
                if ((Time.timeScale < 1 || currentFrame == -1) && unitView.ActionStop == false) // 프레임이 없거나 슬로우 상태
                {
                    animatorTime += deltaTime;
                    animator.speed = 1.0f;
                }
                else
                {
                    animator.speed = 0f;
                }
            }
            else
            {
                if (currentFrame * frameTime - animatorTime >= 0)
                {
                    animator.speed = (currentFrame * frameTime - animatorTime) / deltaTime;
                    animatorFrame = currentFrame;
                    animatorTime = currentFrame * frameTime;
                }
                else
                {
                    animator.speed = 0;
                    animatorFrame = currentFrame;
                }
            }

            if (unitView.Loop)
            {
                var time = animator.GetCurrentAnimatorStateInfo(0).normalizedTime;
                if (time > 1.0f && animator.IsInTransition(0) == false)
                {
                    animator.Play(animHashes[animIndex], 0, time - Mathf.Floor(time));
                }
            }
        }
    }

    public void OnUpdate()
    {
        if (unitView.UseAnimation == false) return;

        //UpdateCurrAnimation();
        if (UpdateCurrAnimation() == false)
        {
            UpdateAnimator();
        }
    }

    private void OnDisable()
    {
        unitView.RemoveUpdate(this);
        unitView = null;
        currentAnim = null;
        ResetPose();
    }
}