using System;
using UnityEngine;

namespace AibisDream.Kit
{
    public class Lerp : IAction
    {
        private static readonly SimpleObjectPool<Lerp> Pool = new(() => new Lerp(), null, 10);

        private float _target;
        private float _source;
        private float _duration;
        private Action<float> _onLerp;
        private Action _onLerpFinish;

        private float _currentTime;

        public static Lerp Allocate(float source, float target, float duration, Action<float> onLerp = null,
            Action onLerpFinish = null)
        {
            var retNode = Pool.Allocate();
            retNode.ActionID = ActionKit.IDGenerator++;
            retNode.IsFinalized = false;
            retNode.Reset();
            retNode._target = target;
            retNode._source = source;
            retNode._duration = duration;
            retNode._onLerp = onLerp;
            retNode._onLerpFinish = onLerpFinish;
            return retNode;
        }

        public bool Paused { get; set; }

        public void Reset()
        {
            Status = ActionStatus.NotStart;
            Paused = false;
            _currentTime = 0.0f;
        }

        public void Deinit()
        {
            if (!IsFinalized)
            {
                IsFinalized = true;
                _onLerp = null;
                _onLerpFinish = null;
                ActionKitMonoBehaviourEvents.AddCallback(new ActionQueueRecycleCallback<Lerp>(Pool, this));
            }
        }

        public ulong ActionID { get; set; }
        public ActionStatus Status { get; set; }

        public void OnStart()
        {
            _currentTime = 0.0f;
            _onLerp?.Invoke(Mathf.Lerp(_source, _target, 0));
        }

        public void OnExecute(float dt)
        {
            _currentTime += dt;
            if (_currentTime < _duration)
            {
                _onLerp?.Invoke(Mathf.Lerp(_source, _target, _currentTime / _duration));
            }
            else
            {
                this.Finish();
            }
        }

        public void OnFinish()
        {
            _onLerp?.Invoke(Mathf.Lerp(_source, _target, 1.0f));
            _onLerpFinish?.Invoke();
        }

        public bool IsFinalized { get; set; }
    }

    public static class LerpExtension
    {
        public static ISequence Lerp(this ISequence self, float a, float b, float duration, Action<float> onLerp = null,
            Action onLerpFinish = null)
        {
            return self.Append(Kit.Lerp.Allocate(a, b, duration, onLerp, onLerpFinish));
        }

        public static ISequence Lerp01(this ISequence self, float duration, Action<float> onLerp = null,
            Action onLerpFinish = null)
        {
            return self.Append(Kit.Lerp.Allocate(0, 1, duration, onLerp, onLerpFinish));
        }
    }
}