using UnityEngine;
using UnityEngine.UIElements;
using Fusion;

namespace Hallucinate.UI
{
    public class PerformanceOverlay : MonoBehaviour
    {
        private static PerformanceOverlay _instance;
        private Label _fpsLabel;
        private UIDocument _uiDocument;
        private VisualElement _root;

        private float _deltaTime = 0f;
        private bool _isVisible = false;

        public static void SetVisible(bool visible)
        {
            if (_instance == null && visible)
            {
                var go = new GameObject("PerformanceOverlay");
                _instance = go.AddComponent<PerformanceOverlay>();
                DontDestroyOnLoad(go);
            }

            if (_instance != null)
            {
                _instance._isVisible = visible;
                if (_instance._root != null)
                {
                    _instance._root.style.display = visible ? DisplayStyle.Flex : DisplayStyle.None;
                }
            }
        }

        private void Awake()
        {
            _uiDocument = gameObject.AddComponent<UIDocument>();
            
            // Đặt thứ tự hiển thị cực cao để luôn nằm trên cùng
            _uiDocument.sortingOrder = 999;

            // Thử lấy PanelSettings từ UIManager để đồng bộ tỉ lệ scale
            if (UIManager.Instance != null && UIManager.Instance.GetComponent<UIDocument>() != null)
            {
                _uiDocument.panelSettings = UIManager.Instance.GetComponent<UIDocument>().panelSettings;
            }
            
            _root = new VisualElement();
            _root.style.position = Position.Absolute;
            _root.style.bottom = 15;
            _root.style.right = 15;
            _root.pickingMode = PickingMode.Ignore;

            _fpsLabel = new Label("0 FPS | 0.0ms | PING: 0ms");
            _fpsLabel.pickingMode = PickingMode.Ignore;
            _fpsLabel.style.color = Color.white;
            _fpsLabel.style.fontSize = 12;
            _fpsLabel.style.unityFontStyleAndWeight = FontStyle.Bold;
            // Shadow effect
            _fpsLabel.style.textShadow = new TextShadow { offset = new Vector2(1, 1), blurRadius = 1, color = Color.black };

            _root.Add(_fpsLabel);
            _uiDocument.rootVisualElement.Add(_root);
            
            _root.style.display = _isVisible ? DisplayStyle.Flex : DisplayStyle.None;
        }

        private void Update()
        {
            if (!_isVisible) return;

            _deltaTime += (Time.unscaledDeltaTime - _deltaTime) * 0.1f;
            float fps = 1.0f / _deltaTime;
            float ms = _deltaTime * 1000.0f;

            int ping = 0;
            if (BasicSpawner.Instance != null && BasicSpawner.Instance.Runner != null && BasicSpawner.Instance.Runner.IsRunning)
            {
                var runner = BasicSpawner.Instance.Runner;
                if (runner.LocalPlayer != PlayerRef.None)
                {
                    ping = (int)(runner.GetPlayerRtt(runner.LocalPlayer) * 1000);
                }
            }

            var (_, deviceLatency) = MouseMetricsHelper.GetMetrics();

            _fpsLabel.text = $"{Mathf.Ceil(fps)} FPS | {ms:F1}ms | LATENCY: {deviceLatency:F0}ms | PING: {ping}ms";
            
            // Color coding based on performance
            if (fps < 30) _fpsLabel.style.color = Color.red;
            else if (fps < 55) _fpsLabel.style.color = Color.yellow;
            else _fpsLabel.style.color = Color.green;
        }
    }
}