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

namespace XED.Hierarchy
{
    public class ScrollItemUI : UnityEngine.MonoBehaviour, IPointerClickHandler//, IBeginDragHandler, IEndDragHandler,
    {
        public TMP_Text nameText;
        public Image iconImage;
        public Image loadProgress;
        public Button expandButton;
        public RectTransform paddingRT;
        public Sprite spriteExpanded;
        public Sprite spriteCollapsed;
        public UnityEvent<HierarchyItem> onClickSingle;
        public UnityEvent<HierarchyItem> onClickAddSingle;
        public UnityEvent<HierarchyItem> onClickMultiple;
        public UnityEvent onToggleExpand;
        public UnityEvent<HierarchyItem> onDragStart;
        public UnityEvent<HierarchyItem> onDragEnd;
        public UnityEvent<PointerEventData> onScroll; 
        public Color selectedColor;
        public HierarchyItem currentItem;
        public Image upperLine;
        public Image lowerLine;
        public Color lineColor;
        public GameObject highLight;
        public List<HierarchyItemSprite> itemSprites;
        private Image backgroundImage;
        private void Awake()
        {
            backgroundImage = GetComponent<Image>();
        }
        public int SetItemData(HierarchyItem item)
        {
            currentItem = item;
            nameText.text = item.name;
            currentItem.isExpanded = item.isExpanded;
            item.onLoadProgress.RemoveAllListeners();
            item.onLoadProgress.AddListener(OnLoadProgress);
            loadProgress.gameObject.SetActive(false);
            HierarchyItemSprite itemSprite = itemSprites.Find((x) => x.type == item.type);
            if (itemSprite != null) iconImage.sprite = itemSprite.sprite;
            expandButton.image.sprite = currentItem.isExpanded == true ? spriteExpanded : spriteCollapsed;

            float width = nameText.GetComponent<RectTransform>().sizeDelta.x + iconImage.GetComponent<RectTransform>().sizeDelta.x;
            float paddingSize = item.layerNum * expandButton.GetComponent<RectTransform>().sizeDelta.x;
            if (item.children.Count > 0)
            {
                expandButton.gameObject.SetActive(true);
                width += expandButton.GetComponent<RectTransform>().sizeDelta.x;
            }
            else
            {
                expandButton.gameObject.SetActive(false);
                paddingSize += expandButton.GetComponent<RectTransform>().sizeDelta.x;
            }
            width += paddingSize;
            paddingRT.sizeDelta = new Vector2(paddingSize, paddingRT.sizeDelta.y);
            upperLine.GetComponent<RectTransform>().offsetMin = new Vector2(paddingSize, 0);
            lowerLine.GetComponent<RectTransform>().offsetMin = new Vector2(paddingSize, 0);
            return Mathf.RoundToInt(width); 
        }
        public void SetSelected(bool selected)
        {
            if (selected)
            {
                backgroundImage.color = selectedColor;
            }
            else
            {
                backgroundImage.color = Color.clear;
            }
        }
        public void SetSelected(List<HierarchyItem> selectedItems)
        {
              if (selectedItems.Contains(currentItem))
            {
                backgroundImage.color = selectedColor;
            }
            else
            { 
                backgroundImage.color = Color.clear;
            }
        }
        public void ToggleExpandCollapse()
        {
            currentItem.isExpanded = !currentItem.isExpanded;
            expandButton.image.sprite = currentItem.isExpanded == true ? spriteExpanded : spriteCollapsed;
            onToggleExpand?.Invoke();
        }
        public void OnPointerClick(PointerEventData eventData)
        {
            if (eventData.button == PointerEventData.InputButton.Left)
            {
                if (Input.GetKey(KeyCode.LeftControl))
                {
                    onClickAddSingle?.Invoke(currentItem);
                }
                else if (Input.GetKey(KeyCode.LeftShift))
                {
                    onClickMultiple?.Invoke(currentItem);
                }
                else
                {
                    onClickSingle?.Invoke(currentItem);
                }
             }
        }
        public void OnBeginDrag(BaseEventData data)
        {
            Debug.Log("DragStart " + currentItem.name);
            onDragStart?.Invoke(currentItem);
        }

        public void OnEndDrag()
        {
            Debug.Log("DragEnd " + currentItem.name);
            onDragEnd?.Invoke(currentItem);
        }
        public void OnEndDrag(BaseEventData data)
        {
            ScrollItemUI itemUI = GetDropTarget(data);
            if (itemUI != null)
                itemUI.OnEndDrag();
        }
        private ScrollItemUI GetDropTarget(BaseEventData data)
        {
            PointerEventData eventData = (PointerEventData)data;
            PointerEventData pointerData = new PointerEventData(EventSystem.current)
            {
                position = eventData.position  
            };

            var results = new System.Collections.Generic.List<RaycastResult>();
            EventSystem.current.RaycastAll(pointerData, results);  

            foreach (var result in results)
            {
                ScrollItemUI itemUI = result.gameObject.GetComponent<ScrollItemUI>();
                if (itemUI != null)  
                {
                    return itemUI;  
                }
            }

            return null;
        }
        public void OnScroll(BaseEventData data)
        {
            PointerEventData eventData = (PointerEventData)data;
            onScroll?.Invoke(eventData);
        }
        public void ActivateUpperHighlight()
        {
            upperLine.color = lineColor;
        }
        public void ActivateLowerHighlight()
        {
            lowerLine.color = lineColor; 
        }
        public void ActivateMidHighlight()
        {
            highLight.SetActive(true);
        }
        public void DeactivateAllHighlights()
        {
            upperLine.color = Color.clear;
            lowerLine.color = Color.clear;
            highLight.SetActive(false);
        }
        public void OnLoadProgress(float ratio)
        {
            if (ratio == 1.0f)
            {
                loadProgress.gameObject.SetActive(false);
                return;
            }
            if (loadProgress.gameObject.activeSelf == false)
            {
                loadProgress.gameObject.SetActive(true);
            }
            loadProgress.fillAmount = ratio;
        }
    }
    [Serializable]
    public class HierarchyItemSprite
    {
        public HierarchyItemType type;
        public Sprite sprite;
    }
}