using System;
using UnityEngine;
using UnityEngine.UI;

namespace Assets.Scripts.UI.Control
{
    [RequireComponent(typeof(ScrollRect))]
    public class PFUIPageHelper : PFUIComponentBase
    {
        public Transform content;
        public GameObject preBtn;
        public GameObject nextBtn;
        public GameObject btnPrefab;
        public int PageIndex { get; set; }
        public int PageSize { get; set; } = 6;
        public int Total { get; set; }

        private Action<int> CallBack { get; set; }
     
        public void Register(Action<int> refresh)
        {
            CallBack = refresh;

            UIManager.AddEvent(preBtn, UnityEngine.EventSystems.EventTriggerType.PointerClick, (e) =>
            {
                Previous();
            });
            UIManager.AddEvent(nextBtn, UnityEngine.EventSystems.EventTriggerType.PointerClick, (e) =>
            {
                Next();
            });
        }
        public void Build()
        {
            Utils.DestroyChildren(content);
            for (int i = 1; i <= Total; i++)
            {
                var g = Instantiate(btnPrefab, content);
                g.transform.Find("Text").GetComponent<Text>().text = i.ToString();
            }
        }
        //上一页
        private void Previous()
        {
            var newIndex = PageIndex - 1;
            var index = newIndex < 0 ? 0 : newIndex;
            if (index != PageIndex)
            {
                PageIndex = index;
                CallBack?.Invoke(PageIndex);
            }
        }
        //下一页
        private void Next()
        {
            var newIndex = PageIndex + 1;
            var index = newIndex >= Total ? Total-1 : newIndex;
            if (index != PageIndex)
            {
                PageIndex = index;
                CallBack?.Invoke(PageIndex);
            }
        }
        //指定到第几页
        private void Redirect(int index)
        {
            PageIndex = index;
            CallBack?.Invoke(PageIndex);
        }
    }
}