using Convention;
using Demo.Editor.UI;
using System;
using System.Collections;
using System.Collections.Generic;
using Unity.Collections;
using UnityEngine;

namespace Demo.Game
{
    public abstract class Updatement<DataType> : TimelineScriptObject where DataType : struct
    {
        [Serializable]
        public class UpdatementEntry
        {
            public float TimePoint = 0;
            public DataType Position = default;
            public MathExtension.EaseCurveType easeCurveType = MathExtension.EaseCurveType.Linear;
        }
        [Serializable]
        public struct UpdatementCompiledEntries: IDisposable
        {
            public NativeArray<float> TimePoints;
            public NativeArray<DataType> Positions;
            public NativeArray<MathExtension.EaseCurveType> EaseCurveTypes;
            public readonly int Count;

            public UpdatementCompiledEntries(NativeArray<float> timePoints,
                                             NativeArray<DataType> positions,
                                             NativeArray<MathExtension.EaseCurveType> easeCurveTypes,
                                             int count)
            {
                TimePoints = timePoints;
                Positions = positions;
                EaseCurveTypes = easeCurveTypes;
                Count = count;
            }

            public void Dispose()
            {
                if (TimePoints.IsCreated)
                    TimePoints.Dispose();
                if (Positions.IsCreated)
                    Positions.Dispose();
                if (EaseCurveTypes.IsCreated)
                    EaseCurveTypes.Dispose();
            }
        }

        public int Content = 0;
        private readonly List<UpdatementEntry> Entries = new();
        public UpdatementCompiledEntries CompiledEntries;
        protected abstract void UpdateData(DataType data);
        protected abstract DataType Lerp(DataType begin, DataType end, float t);

        /// <summary>
        /// 添加数据
        /// </summary>
        /// <param name="time"></param>
        /// <param name="position"></param>
        /// <param name="curveType"></param>
        public void ManualAddEntry(float time, DataType position, MathExtension.EaseCurveType curveType)
        {
            Entries.Add(new()
            {
                TimePoint = time,
                Position = position,
                easeCurveType = curveType
            });
        }

        private void BuildupCompiledEntriesAndReleaseEntries()
        {
            Entries.Sort((x, y) => x.TimePoint.CompareTo(y.TimePoint));
            CompiledEntries = new(
                new NativeArray<float>(Entries.Count, Allocator.Persistent, NativeArrayOptions.UninitializedMemory),
                new NativeArray<DataType>(Entries.Count, Allocator.Persistent, NativeArrayOptions.UninitializedMemory),
                new NativeArray<MathExtension.EaseCurveType>(Entries.Count, Allocator.Persistent, NativeArrayOptions.UninitializedMemory),
                Entries.Count
            );
            int index = 0;
            foreach (var item in Entries)
            {
                CompiledEntries.TimePoints[index] = item.TimePoint;
                CompiledEntries.Positions[index] = item.Position;
                CompiledEntries.EaseCurveTypes[index] = item.easeCurveType;
                index++;
            }
            Entries.Clear();
        }

        private void UpdateEntry(int start, float percent)
        {
            int head = start;
            int tail = Mathf.Min(start + 1, CompiledEntries.Count - 1);
            UpdateData(Lerp(CompiledEntries.Positions[start],
                            CompiledEntries.Positions[tail],
                            MathExtension.Evaluate(Mathf.Clamp01(percent), CompiledEntries.EaseCurveTypes[head])));
        }

        protected override IEnumerator DoSomethingDuringApplyScript()
        {
            yield return base.DoSomethingDuringApplyScript();
            BuildupCompiledEntriesAndReleaseEntries();
            if (UpdateTarget == null)
            {
                UpdateTarget = Parent.gameObject;
            }
        }

        public override void ResetEnterGameStatus()
        {
            base.ResetEnterGameStatus();
            if (CompiledEntries.Count <= 1)
                return;
            UpdateEntry(0, 0);
        }

        public override IEnumerator UnloadScript()
        {
            Content = 0;
            CompiledEntries = default;
            yield return base.UnloadScript();
        }

        protected override void UpdateTicks(float currentTime, float deltaTime, TickType tickType)
        {
            base.UpdateTicks(currentTime, deltaTime, tickType);

            float GetPercentValue()
            {
                if (Content + 1 == CompiledEntries.Count)
                    return 1;
                return (currentTime - CompiledEntries.TimePoints[Content]) / (CompiledEntries.TimePoints[Content + 1] - CompiledEntries.TimePoints[Content]);
            }

            if (CompiledEntries.Count <= 1)
                return;
            switch (tickType)
            {
                case TickType.Reset:
                case TickType.Start:
                    {
                        Content = 0;
                        while (Content + 1 < CompiledEntries.Count && CompiledEntries.TimePoints[Content + 1] < currentTime)
                            Content++;
                        UpdateEntry(Content, GetPercentValue());
                    }
                    break;
                default:
                    if (CompiledEntries.TimePoints[0] > currentTime)
                        return;
                    if (Content + 1 < CompiledEntries.Count && CompiledEntries.TimePoints[Content + 1] < currentTime)
                        Content++;
                    if (Content + 1 > CompiledEntries.Count)
                        return;
                    UpdateEntry(Content, GetPercentValue());
                    break;
            }
        }

        public DataType Evaluate(float time)
        {
            if (CompiledEntries.Count == 0)
                return default;
            if (CompiledEntries.Count == 1)
                return CompiledEntries.Positions[0];
            if (time < CompiledEntries.TimePoints[0])
                return CompiledEntries.Positions[0];
            for (int i = 1; i < CompiledEntries.Count; i++)
            {
                if (CompiledEntries.TimePoints[i - 1] <= time && CompiledEntries.TimePoints[i] > time)
                {
                    return Lerp(CompiledEntries.Positions[i - 1], CompiledEntries.Positions[i],
                        (time - CompiledEntries.TimePoints[i - 1]) / (CompiledEntries.TimePoints[i] - CompiledEntries.TimePoints[i - 1]));
                }
            }
            return CompiledEntries.Positions[^1];
        }

        [Content] public GameObject UpdateTarget;

        /// <summary>
        /// 设置更新对象
        /// </summary>
        [Convention.RScript.Variable.Attr.Method]
        public void SetUpdateTarget(ScriptableObject target)
        {
            UpdateTarget = target.gameObject;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="item">实例在父类中控制</param>
        protected override void SetupTimelineItem(TimelineItem item)
        {
            if (CompiledEntries.Count == 0)
                return;

            item.SetupDuration(new(CompiledEntries.TimePoints[0], CompiledEntries.TimePoints[^1]), GetTimelineItemColor());
        }

        private void OnDestroy()
        {
            CompiledEntries.Dispose();
        }
    }
}