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

public class xiaozhigou : MonoBehaviour
{
    public Camera mainCamera;              // 玩家摄像机
    public RectTransform uiCanvas;         // UI Canvas 的 RectTransform
    public GameObject targetIconPrefab;    // UI 图标的预制体
    private LinkedList<GameObject> playerList = new LinkedList<GameObject>(); // 存储标签为 "Player" 的对象
    private GameObject peopleposition;//位置的信息
    private Dictionary<GameObject, RectTransform> playerUIMap = new Dictionary<GameObject, RectTransform>(); // 存储角色与对应的 UI 标记

    private void Start()
    {
        peopleposition = GameObject.Find("peopleposition");
        if (peopleposition == null)
        {
            Debug.LogError("请确保场景中有一个名为 'peopleposition' 的 GameObject 作为 UI 的父物体。");
            return;
        }

        // 初始化获取当前场景中所有的 "Player" 标签对象并创建 UI 标记
        UpdatePlayerList();
        CreateUIForPlayers();
    }

    void Update()
    {
        // 实时更新 Player 列表和对应的 UI
        UpdatePlayerList();
        UpdateUIForPlayers();
    }

    // 更新链表中的 "Player" 对象
    private void UpdatePlayerList()
    {
        // 获取所有带有 "Player" 标签的对象
        GameObject[] players = GameObject.FindGameObjectsWithTag("Player");

        // 检查新增的 Player
        foreach (GameObject player in players)
        {
            if (!playerList.Contains(player)) // 新增的角色
            {
                playerList.AddLast(player);

                // 为新增角色创建 UI 标记
                if (!playerUIMap.ContainsKey(player))
                {
                    CreateUIForPlayer(player);
                }
            }
        }

        // 检查已移除的 Player
        var node = playerList.First;
        while (node != null)
        {
            var nextNode = node.Next;

            if (!System.Array.Exists(players, p => p == node.Value))
            {
                // 如果角色已被移除，删除对应的 UI 标记
                if (playerUIMap.ContainsKey(node.Value))
                {
                    Destroy(playerUIMap[node.Value].gameObject);
                    playerUIMap.Remove(node.Value);
                }

                playerList.Remove(node);
            }

            node = nextNode;
        }
    }

    // 为所有玩家创建 UI 标记
    private void CreateUIForPlayers()
    {
        foreach (var player in playerList)
        {
            if (!playerUIMap.ContainsKey(player))
            {
                CreateUIForPlayer(player);
            }
        }
    }

    // 为单个玩家创建 UI 标记
    private void CreateUIForPlayer(GameObject player)
    {
        if (targetIconPrefab == null || uiCanvas == null)
        {
            Debug.LogError("请确保已设置 TargetIconPrefab 和 uiCanvas。");
            return;
        }

        // 实例化 UI 图标
        GameObject iconInstance = Instantiate(targetIconPrefab, peopleposition.transform);

        // 获取 RectTransform 用于设置位置
        RectTransform iconRectTransform = iconInstance.GetComponent<RectTransform>();

        // 设置初始内容
        Text nameText = iconInstance.GetComponentInChildren<Text>();
        if (nameText != null)
        {
            nameText.text = player.name; // 显示角色名称
        }

        // 将 UI 图标与玩家对应
        playerUIMap[player] = iconRectTransform;
    }

    // 实时更新所有玩家的 UI
    private void UpdateUIForPlayers()
    {
        foreach (var player in playerList)
        {
            if (!playerUIMap.ContainsKey(player)) continue;

            RectTransform targetIcon = playerUIMap[player];

            // 获取玩家的屏幕坐标
            Vector3 screenPoint = mainCamera.WorldToScreenPoint(player.transform.position);

            // 检查玩家是否在屏幕内
            if (screenPoint.z > 0 && screenPoint.x > 0 && screenPoint.x < Screen.width && screenPoint.y > 0 && screenPoint.y < Screen.height)
            {
                // 玩家在屏幕内，显示图标
                targetIcon.gameObject.SetActive(true);
                targetIcon.position = screenPoint;

                //// 更新图标内容
                //Text nameText = targetIcon.GetComponentInChildren<Text>();
                //if (nameText != null)
                //{
                //    float distance = Vector3.Distance(mainCamera.transform.position, player.transform.position);
                //    nameText.text = $"{player.name}\n距离: {distance:F1} 米";
                //}
            }
            else
            {
                // 玩家不在屏幕内，隐藏图标
                targetIcon.gameObject.SetActive(false);
            }
        }
    }
}