using UnityEngine;
using System.Collections.Generic;
using UnityEngine.EventSystems;
 
public class GestureUnlock : MonoBehaviour, IBeginDragHandler, IEndDragHandler, IDragHandler
{
 private List<GameObject> lrList = new List<GameObject>();//存儲每個LineRenderer的列表
 private List<GameObject> passwordButtonList = new List<GameObject>();//存儲每個密碼按鈕的列表
 
 private Vector3 startPos;//鼠標開始的位置
 
 //線的參數
 public Color startColor = Color.black;//線開始的顏色
 public Color endColor = Color.black;//線結束的顏色
 public float width = 0.1f;//線寬度
 public int vertices = 90;//頂點數
 
 public string password;//密碼
 private string inputPassword;//輸入的密碼
 
 /// <summary>
 /// 刷新線段(拖拽過程中一直刷新)
 /// </summary>
 private void RefreshLine()
 {
 if (passwordButtonList.Count == 0)
 {
 return;
 }
 
 LineRenderer uncompleteLR = SpawnLineRenderer(false);
 InitLine(uncompleteLR);
 DrawLine(uncompleteLR, startPos, ScreenToWorld(Input.mousePosition));
 ClearLine(false);
 }
 
 /// <summary>
 /// 繪制已經連線完成的線段
 /// </summary>
 private void DrawCompleteLine(Vector3 endPos)
 {
 LineRenderer completeLR = SpawnLineRenderer(true);
 InitLine(completeLR);
 DrawLine(completeLR, startPos, endPos);
 }
 
 /// <summary>
 /// 記錄密碼
 /// </summary>
 /// <param name="_passwordBlock">密碼塊物體</param>
 private void RecordPassword(GameObject _passwordButton)
 {
 passwordButtonList.Add(_passwordButton);
 inputPassword += _passwordButton.name;
 
 startPos = _passwordButton.transform.position;//記錄起始位置
 }
 
 /// <summary>
 /// 刪除密碼
 /// </summary>
 private void DeletePassword()
 {
 passwordButtonList.Clear();
 inputPassword = "";
 }
 
 public void OnBeginDrag(PointerEventData eventData)
 {
 ClearLine(true);//每次開始拖拽時清空所有線段
 
 GameObject go = eventData.pointerEnter;
 if (go != null && go.tag == "PasswordButton" && IsExistInPasswordBlockList(go) == false)
 {
 RecordPassword(go);//記錄密碼
 }
 }
 
 public void OnEndDrag(PointerEventData eventData)
 {
 ClearUnCompleteLine();//清除未完成的線段
 }
 
 public void OnDrag(PointerEventData eventData)
 {
 RefreshLine();//刷新線段(拖拽過程中一直刷新)
 
 GameObject go = eventData.pointerEnter;
 if (passwordButtonList.Count != 0 && go != null && go.tag == "PasswordButton" && IsExistInPasswordBlockList(go) == false)
 {
 DrawCompleteLine(go.transform.position);//繪制已經連線完成的線段
 
 RecordPassword(go);//記錄密碼
 }
 }
 
 #region 線段相關操作
 
 /// <summary>
 /// 生成LineRenderer
 /// </summary>
 private LineRenderer SpawnLineRenderer(bool isCompleteLine)
 {
 LineRenderer uncompleteLR = new GameObject().AddComponent<LineRenderer>();
 uncompleteLR.material = new Material(Shader.Find("Sprites/Default"));
 lrList.Add(uncompleteLR.gameObject);
 if (isCompleteLine)
 {
 uncompleteLR.gameObject.name = "CompleteLine";
 }
 else
 {
 uncompleteLR.gameObject.name = "UncompleteLine";
 }
 return uncompleteLR;
 }
 
 /// <summary>
 /// 初始化線
 /// </summary>
 private void InitLine(LineRenderer _uncompleteLR)
 {
 _uncompleteLR.startColor = startColor;
 _uncompleteLR.endColor = endColor;
 _uncompleteLR.startWidth = width;
 _uncompleteLR.endWidth = width;
 _uncompleteLR.numCapVertices = vertices;
 _uncompleteLR.numCornerVertices = vertices;
 }
 
 /// <summary>
 /// 兩點繪制一條直線
 /// </summary>
 /// <param name="_uncompleteLR">線段</param>
 /// <param name="startPos">起始位置</param>
 /// <param name="endPos">結束位置</param>
 private void DrawLine(LineRenderer _uncompleteLR, Vector3 startPos, Vector3 endPos)
 {
 _uncompleteLR.positionCount = 2;
 startPos.z = 0;
 endPos.z = 0;
 _uncompleteLR.SetPosition(0, startPos);
 _uncompleteLR.SetPosition(1, endPos);
 }
 
 /// <summary>
 /// 清除線段
 /// </summary>
 /// <param name="clearAll">是否清除全部線段</param>
 private void ClearLine(bool clearAll)
 {
 if (lrList.Count == 0)
 {
 return;
 }
 
 for (int i = lrList.Count - 1; i >= 0; i--)
 {
 GameObject go = lrList[i];
 if (clearAll)
 {
 Destroy(go);
 lrList.Remove(go);
 }
 else
 {
 if (go.name != "CompleteLine" && i != lrList.Count - 1)
 {
  Destroy(go);
  lrList.Remove(go);
 }
 }
 }
 
 if (clearAll)
 {
 DeletePassword();
 }
 }
 
 /// <summary>
 /// 清除未完成的線段(每次拖拽結束時清除)
 /// </summary>
 private void ClearUnCompleteLine()
 {
 if (lrList.Count == 0)
 {
 return;
 }
 
 GameObject go = lrList[lrList.Count - 1];
 Destroy(go);
 lrList.Remove(go);
 }
 
 #endregion
 
 #region 工具方法
 
 /// <summary>
 /// 當前密碼塊是否存在于密碼塊列表中
 /// </summary>
 /// <param name="_passwordBlock">密碼塊</param>
 private bool IsExistInPasswordBlockList(GameObject _passwordButton)
 {
 if (passwordButtonList.Count == 0)
 {
 return false;
 }
 
 if (passwordButtonList.Contains(_passwordButton))
 {
 return true;
 }
 else
 {
 return false;
 }
 }
 
 /// <summary>
 /// 屏幕坐標轉世界坐標
 /// </summary>
 /// <param name="screenPos">屏幕坐標位置</param>
 /// <param name="camera">相機</param>
 /// <returns>轉換后的世界坐標</returns>
 private Vector3 ScreenToWorld(Vector3 screenPos, Camera camera = null)
 {
 if (camera == null)
 {
 camera = Camera.main;
 }
 Vector3 _screenPos = new Vector3(screenPos.x, screenPos.y, -camera.transform.position.z);
 Vector3 v = camera.ScreenToWorldPoint(_screenPos);
 return v;
 }
 
 #endregion
}