using UnityEngine;
using UnityEngine.UI;
using TMPro;

namespace Northbound
{
    /// <summary>
    /// 건물 위에 표시되는 체력바
    /// </summary>
    public class BuildingHealthBar : MonoBehaviour
    {
        [Header("UI References")]
        public Image fillImage;
        public TextMeshProUGUI healthText;
        public GameObject barContainer;

        [Header("Settings")]
        public float heightOffset = 3f;
        public bool hideWhenFull = true;
        public float hideDelay = 3f;

        [Header("Colors")]
        public Color fullHealthColor = Color.green;
        public Color mediumHealthColor = Color.yellow;
        public Color lowHealthColor = Color.red;
        public float mediumHealthThreshold = 0.6f;
        public float lowHealthThreshold = 0.3f;

        private Building _building;
        private Camera _mainCamera;
        private float _lastDamageTime;
        private Canvas _canvas;

        private void Awake()
        {
            // Canvas 설정
            _canvas = GetComponent<Canvas>();
            if (_canvas == null)
            {
                _canvas = gameObject.AddComponent<Canvas>();
            }
            _canvas.renderMode = RenderMode.WorldSpace;

            // Canvas Scaler 설정
            var scaler = GetComponent<CanvasScaler>();
            if (scaler == null)
            {
                scaler = gameObject.AddComponent<CanvasScaler>();
            }
            scaler.dynamicPixelsPerUnit = 10f;
        }

        private void Start()
        {
            _mainCamera = Camera.main;
        }

        public void Initialize(Building building)
        {
            _building = building;
            transform.localPosition = Vector3.up * heightOffset;
        }

        public void UpdateHealth(int currentHealth, int maxHealth)
        {
            if (fillImage != null)
            {
                float healthPercentage = maxHealth > 0 ? (float)currentHealth / maxHealth : 0f;
                fillImage.fillAmount = healthPercentage;

                // 체력에 따른 색상 변경
                fillImage.color = GetHealthColor(healthPercentage);
            }

            if (healthText != null)
            {
                healthText.text = $"{currentHealth}/{maxHealth}";
            }

            // 체력바 표시/숨김
            if (barContainer != null)
            {
                _lastDamageTime = Time.time;
                barContainer.SetActive(true);
            }
        }

        private void Update()
        {
            // 카메라를 향하도록 회전
            if (_mainCamera != null)
            {
                transform.rotation = Quaternion.LookRotation(transform.position - _mainCamera.transform.position);
            }

            // 체력이 가득 차면 숨김
            if (hideWhenFull && barContainer != null && _building != null)
            {
                float healthPercentage = _building.GetHealthPercentage();
                
                if (healthPercentage >= 1f && Time.time - _lastDamageTime > hideDelay)
                {
                    barContainer.SetActive(false);
                }
            }
        }

        private Color GetHealthColor(float healthPercentage)
        {
            if (healthPercentage <= lowHealthThreshold)
                return lowHealthColor;
            else if (healthPercentage <= mediumHealthThreshold)
                return mediumHealthColor;
            else
                return fullHealthColor;
        }
    }
}