using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;

public class NovelScrollViewScript : MonoBehaviour, IBeginDragHandler, IEndDragHandler
{
    // Get Component
    ScrollRect rect;
    public int totalCount;
    public BookAudioPlayer m_bookAudioPlayerPrefabs;
    public Transform m_bookAudioPlayerParent;
    public List<BookAudioPlayer> m_bookAudioList;
    private float[] posArray;

    private float targetPos;
    private int targetIndex = 0;
    private bool isDrag = false;
    private bool isStartDrag = false;
    public void OnBeginDrag(PointerEventData eventData)
    {
        isDrag = true;
        isStartDrag = true;
        m_bookAudioList[targetIndex].Pause();
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        isDrag = false;
        Vector2 pos = rect.normalizedPosition;
        float x = Mathf.Abs(pos.x - posArray[0]);
        targetIndex = 0;
        for (int i = 1; i < totalCount; ++i)
        {
            float tmp = Mathf.Abs(pos.x - posArray[i]);
            if (tmp < x)
            {
                x = tmp;
                targetIndex = i;
            }
        }
        targetPos = posArray[targetIndex];
    }

    public void Init(List<PuzzleNovel> puzzleNovels)
    {
        for(int j=0;j<m_bookAudioList.Count;j++)
        {
            Destroy(m_bookAudioList[j].gameObject);
        }
        m_bookAudioList.Clear();
        rect = GetComponent<ScrollRect>();
        totalCount = puzzleNovels.Count;
        posArray = new float[totalCount];
        for (int i = 0; i < totalCount-1; i++)
        {
            posArray[i] = (float)i / (totalCount-1);
        }
        posArray[totalCount - 1] = 1.0f;
        for(int j=0;j<puzzleNovels.Count;j++)
        {
            GameObject go = GameObject.Instantiate(m_bookAudioPlayerPrefabs.gameObject,m_bookAudioPlayerParent);
            BookAudioPlayer currPlayer = go.GetComponent<BookAudioPlayer>();
            currPlayer.Init(puzzleNovels[j]);
            m_bookAudioList.Add(currPlayer);
        }
        m_bookAudioPlayerParent.GetComponent<RectTransform>().sizeDelta = new Vector2(Screen.width*puzzleNovels.Count,Screen.height);
    }

    // Update is called once per frame
    void Update()
    {
        if (!isDrag)
        {
            rect.horizontalNormalizedPosition = Mathf.Lerp(rect.horizontalNormalizedPosition, targetPos, Time.deltaTime * 8);
            if(rect.horizontalNormalizedPosition-targetPos<0.01f && isStartDrag)
            {
                m_bookAudioList[targetIndex].Resume();
                isStartDrag = false;
            }
        }
    }

}