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

public class PhotoScroll : MonoBehaviour, IBeginDragHandler, IEndDragHandler{
    public ScrollRect scrollRect;
    private Vector2 startDragPos;      // 拖曳开始位置
    [SerializeField]  TextMeshProUGUI 相片總數_tb,相片目前_tb,扶手長度_tb,報告書號_tb;
    private float currentPage=0;
    public float swipeThreshold = 200f; 
    public static bool currentPageChange;
    void   Update() {
        if (currentPageChange){
            currentPageChange=false;
            currentPage=0;
        }
    }
    public void OnBeginDrag(PointerEventData eventData){
        startDragPos = eventData.position;
    }

    public void OnEndDrag(PointerEventData eventData){

        float dragDistance = Mathf.Abs(eventData.position.x - startDragPos.x);
        if (dragDistance > swipeThreshold){
            if(eventData.position.x > startDragPos.x){
                ShowPreviousPage();
            }else{
                ShowNextPage();
            }
        }else{
            SnapToNearestPage();
        }
    }
    private void ShowPreviousPage()
    {
        if (currentPage > 0)
        {
            currentPage--;
            float normalizedPosition = (float)currentPage / (float)(float.Parse(相片總數_tb.text)-1);
            StartCoroutine(SmoothScrollTo(normalizedPosition));
            UpdatePageIndicator();
        }
    }

    private void ShowNextPage() {
        if(相片總數_tb.text !="-"){
            if (currentPage < float.Parse(相片總數_tb.text) - 1){
                currentPage++;
                float normalizedPosition = (float)currentPage / (float)(float.Parse(相片總數_tb.text)-1 );
                StartCoroutine(SmoothScrollTo(normalizedPosition));
                UpdatePageIndicator();
            }
        }
    }

    private IEnumerator SmoothScrollTo(float targetNormalizedPosition)
    {
        while (Mathf.Abs(scrollRect.horizontalNormalizedPosition - targetNormalizedPosition) > 0.01f)
        {
            scrollRect.horizontalNormalizedPosition = Mathf.Lerp(scrollRect.horizontalNormalizedPosition, targetNormalizedPosition, 10f * Time.deltaTime);
            yield return null;
        }
        scrollRect.horizontalNormalizedPosition = targetNormalizedPosition;
    }

    private void SnapToNearestPage()
    {
        float targetNormalizedPosition = currentPage / (float)(float.Parse(相片總數_tb.text)-1);
        StartCoroutine(SmoothScrollTo(targetNormalizedPosition));
    }
    public void UpdatePageIndicator(){
        相片目前_tb.text=(currentPage + 1).ToString();
        if (Main.Global.報告書施工狀態 == "施工前"){
            string 文件號 =  Main.Global.報告書施工圖片_table.Rows[int.Parse(currentPage.ToString())][0].ToString();
            Main.Global.報告書施工圖檔文件號 = 文件號;
            SQL_Comm.SQL_報告書_施工圖檔扶手長度(報告書號_tb.text,Main.Global.報告書文件號,Main.Global.報告書物料料號,Main.Global.報告書物料明細流水號,文件號);
            if(SQL_Module.dr.Read()){
                扶手長度_tb.text=SQL_Module.dr[0].ToString();
            }else{
                扶手長度_tb.text="";
            }
        }else{
            扶手長度_tb.text="";
        }
        
        
    }
    public static void 清除currentPage(){
        currentPageChange=true;
    }
}