using System;
using System.Collections;
using System.Collections.Generic;
using Ichni.RhythmGame;
using UniRx;
using UnityEngine;
using UnityEngine.Serialization;

namespace Ichni.Editor
{
    public partial class TimePointerModule : MonoBehaviour
    {
        private Timeline timeline => EditorManager.instance.uiManager.timeline;
        private SongInformation songInformation => EditorManager.instance.songInformation;

        public GameObject timePointerPrefab;
        public List<TimePointer> timePointerList;

        public RectTransform timePointerArea;
        public RectTransform visibleTimePointerArea;
        public RectTransform moveTabPoint;//用于显示timeline上的tab
        public RectTransform mainTimePointer;

        public float intervalUnit;
        public float timePointerInterval;
        public float sizeNegative, sizePositive;
        public int negativePointerAmount; // 负方向指示线的数量
        public int positivePointerAmount, totalPointerAmount;
        /// <summary>
        /// delay时间区间中，(-delay, 0)的距离偏移量
        /// </summary>
        public float delayDistanceOffset;

        public float leftSideSongTime, rightSideSongTime, songTimeDistance;

        private void Start()
        {
            Observable.NextFrame().Subscribe(_ =>
            {
                timePointerList = new List<TimePointer>();
                Initialize(songInformation.delay, songInformation.bpm);
            });
        }

        private void Update()
        {
            if (EditorManager.instance.musicPlayer.isPlaying)
            {
                SetRange(songInformation.songTime);

            }


            timePointerList.ForEach(pointer =>
            {
                bool isActive = pointer.time >= leftSideSongTime && pointer.time <= rightSideSongTime;
                pointer.gameObject.SetActive(isActive);
            });
            if (OnePointer != null) moveTabPoint.localPosition =
            new Vector3(timePointerArea.localPosition.x + OnePointer.transform.localPosition.x - timePointerInterval, 0, 0);

            foreach (var i in moveTabPoint.transform.GetComponentsInChildren<SubTab>())
            {
                if (i.Time >= songInformation.songTime)
                {
                    i.transform.localScale = new Vector3(1, 1, 1);
                }
                else
                {
                    i.transform.localScale = new Vector3(0, 0, 0);
                }
            }

        }

        /// <summary>
        /// 初始化所有Timeline指示线
        /// </summary>
        /// <param name="delay"></param>
        /// <param name="bpm"></param>
        public void Initialize(float delay, float bpm)
        {
            timePointerInterval = 80;
            ClearPointers();

            int beatDivider = 1;

            intervalUnit = (60f / bpm) / beatDivider * 1000;

            sizeNegative = delay * beatDivider / timeline.timePerBeat;

            // 计算负方向指示线的数量
            negativePointerAmount = Mathf.CeilToInt(sizeNegative);

            sizePositive = songInformation.song.length * beatDivider / timeline.timePerBeat;

            positivePointerAmount = Mathf.CeilToInt(sizePositive);

            totalPointerAmount = negativePointerAmount + positivePointerAmount;

            timePointerArea.sizeDelta = new Vector2(timePointerInterval * (sizeNegative + sizePositive), 60f);

            delayDistanceOffset = timePointerInterval * (negativePointerAmount - sizeNegative);

            leftSideSongTime = timeline.beatmapStartTime;
            rightSideSongTime = timeline.timePerBeat * (visibleTimePointerArea.rect.width / timePointerInterval);
            songTimeDistance = rightSideSongTime;

            for (int i = -negativePointerAmount; i <= positivePointerAmount; i++)
            {
                CreatePointer(beatDivider, i);
            }

            //ChangeSongTimeDistance(0);
            SetRange(timeline.beatmapStartTime);
        }
    }

    public partial class TimePointerModule
    {
        /// <summary>
        /// 设置Timeline的显示区间，区间宽度使用当前的区间宽度
        /// </summary>
        /// <param name="startTime">开始时间，结束时间即（开始时间+区间宽度）</param>
        public void SetRange(float startTime)
        {
            startTime = Mathf.Clamp(startTime, timeline.beatmapStartTime, songInformation.song.length);

            timePointerArea.anchoredPosition =
                new Vector2((timePointerArea.sizeDelta.x / 2) -
                            (startTime + songInformation.delay) / timeline.timePerBeat * timePointerInterval, 0);

            float proportion = mainTimePointer.anchoredPosition.x / visibleTimePointerArea.rect.width;

            leftSideSongTime = startTime - songTimeDistance * proportion;
            rightSideSongTime = startTime + songTimeDistance * (1 - proportion);
        }

        /// <summary>
        /// 生成指示线
        /// </summary>
        /// <param name="beatDivider">细分X分音符</param>
        /// <param name="index"></param>
        TimePointer OnePointer = null;
        private void CreatePointer(int beatDivider, int index)
        {
            TimePointer pointer = Instantiate(timePointerPrefab, timePointerArea).GetComponent<TimePointer>();
            timePointerList.Add(pointer);
            pointer.index = index;

            pointer.GetComponent<RectTransform>().anchoredPosition =
                new Vector2((index + negativePointerAmount) * timePointerInterval + 15f - delayDistanceOffset, 0);

            pointer.time = index * intervalUnit / 1000f;
            pointer.intervalUnitText.text = Mathf.RoundToInt(index * intervalUnit).ToString();
            if (index == 0)
            {
                OnePointer = timePointerList[timePointerList.Count - 1];
            }
            if (beatDivider > 1)
            {

            }
        }

        /// <summary>
        /// 更新指示线位置
        /// </summary>
        public void UpdatePointers()
        {
            // 计算延迟距离偏移量
            delayDistanceOffset = timePointerInterval * (negativePointerAmount - sizeNegative);

            // 更新指示线区域的大小
            timePointerArea.sizeDelta = new Vector2(timePointerInterval * totalPointerAmount, 55f);

            // 更新每个指示线的位置
            foreach (var pointer in timePointerList)
            {
                pointer.GetComponent<RectTransform>().anchoredPosition =
                    new Vector2((pointer.index + negativePointerAmount) * timePointerInterval + 15f - delayDistanceOffset, 0);
            }
        }

        /// <summary>
        /// 清楚所有指示线
        /// </summary>
        private void ClearPointers()
        {
            foreach (var pointer in timePointerList)
            {
                Destroy(pointer.gameObject);
            }
            timePointerList.Clear();
        }

        /// <summary>
        /// 缩放时间线的展示时间宽度
        /// </summary>
        /// <param name="value">增减值</param>
        public void ChangeSongTimeDistance(float value)
        {
            float oldDistance = songTimeDistance;
            float changedDistance = songTimeDistance + value;
            float songLength = songInformation.song.length;
            if (changedDistance < 1 || changedDistance > songLength)
            {
                return;
            }

            float finalDistance = 0, finalValue = 0;
            float superfluousDistance = changedDistance - songLength;
            if (superfluousDistance > 0)
            {
                finalDistance = songLength;
                finalValue = value - superfluousDistance;
            }
            else
            {
                finalDistance = changedDistance;
                finalValue = value;
            }


            songTimeDistance = finalDistance;
            float proportion = mainTimePointer.anchoredPosition.x /
                               visibleTimePointerArea.rect.width;
            leftSideSongTime -= finalValue * (proportion);
            rightSideSongTime += finalValue * (1 - proportion);

            if (leftSideSongTime < -songInformation.delay)
            {
                rightSideSongTime += Mathf.Abs(leftSideSongTime);
                leftSideSongTime = -songInformation.delay;
            }
            else if (rightSideSongTime > songLength)
            {
                leftSideSongTime -= (rightSideSongTime - songLength);
                rightSideSongTime = songLength;
            }

            timePointerInterval = timePointerInterval / finalDistance * oldDistance;
            UpdatePointers();
            //UpdateListItems();
            SetRange(leftSideSongTime);
        }
    }
}