using UnityEngine;
using UnityEngine.UI;
using IndianOceanAssets.Engine2_5D;

namespace GameFramework
{
    /// <summary>
    /// 游戏内 HUD —— 魂灵计数 + 生命图标 + 技能CD。
    /// 
    /// 布局：
    /// - 左上角：收集到的魂灵（icon + 数字）
    /// - 左下角：5个生命图标
    /// - 右下角：3个技能图标（冲刺/摇铃/灵灯）+ CD遮罩
    /// </summary>
    public class GameHUD : MonoBehaviour
    {
        [Header("魂灵计数（左上角）")]
        [SerializeField] private Image soulIcon;
        [SerializeField] private Text soulCountText;

        [Header("生命图标（左下角）")]
        [SerializeField] private Image[] lifeIcons; // 5个生命图标

        [Header("技能图标（右下角）")]
        [SerializeField] private Image skillSprintIcon;
        [SerializeField] private Image skillSprintCD;   // CD 遮罩（Image.fillAmount）
        [SerializeField] private Image skillBellIcon;
        [SerializeField] private Image skillBellCD;
        [SerializeField] private Image skillLanternIcon;
        [SerializeField] private Image skillLanternCD;

        [Header("暂停")]
        [SerializeField] private Button pauseButton;

        private HealthSystem _playerHealth;
        private SpiritLanternSystem _lanternSystem;
        private EchoSystem _echoSystem;
        private PlayerController _playerController;
        private int _maxHealth = 5;

        void Start()
        {
            var player = GameObject.FindWithTag("Player");
            if (player != null)
            {
                _playerHealth = player.GetComponent<HealthSystem>();
                _lanternSystem = player.GetComponent<SpiritLanternSystem>();
                _echoSystem = player.GetComponent<EchoSystem>();
                _playerController = player.GetComponent<PlayerController>();
            }

            if (pauseButton != null)
                pauseButton.onClick.AddListener(OnPauseClick);

            // 订阅分数事件（魂灵计数复用分数系统）
            ScoreManager.onScoreChanged += UpdateSoulCount;
            UpdateSoulCount(ScoreManager.Instance != null ? ScoreManager.Instance.CurrentScore : 0);

            UpdateLifeIcons();

            // 自动创建受击泛红特效（如果场景中没有）
            if (FindObjectOfType<DamageFlashOverlay>() == null)
            {
                var overlayObj = new GameObject("DamageFlashOverlay");
                overlayObj.AddComponent<DamageFlashOverlay>();
            }
        }

        void OnDestroy()
        {
            ScoreManager.onScoreChanged -= UpdateSoulCount;
        }

        void Update()
        {
            UpdateLifeIcons();
            UpdateSkillCooldowns();
        }

        /// <summary>
        /// 更新魂灵计数（左上角）。
        /// </summary>
        private void UpdateSoulCount(int count)
        {
            if (soulCountText != null)
                soulCountText.text = count.ToString();
        }

        /// <summary>
        /// 更新生命图标（左下角）。
        /// 根据当前血量显示/隐藏对应图标。
        /// </summary>
        private void UpdateLifeIcons()
        {
            if (_playerHealth == null || lifeIcons == null || lifeIcons.Length == 0) return;

            // 获取当前血量
            var healthField = typeof(HealthSystem).GetField("health",
                System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
            int currentHealth = healthField != null ? (int)healthField.GetValue(_playerHealth) : _maxHealth;

            for (int i = 0; i < lifeIcons.Length; i++)
            {
                if (lifeIcons[i] != null)
                    lifeIcons[i].enabled = (i < currentHealth);
            }
        }

        /// <summary>
        /// 更新技能CD遮罩（右下角）。
        /// 使用 Image.fillAmount 实现圆形CD效果。
        /// </summary>
        private void UpdateSkillCooldowns()
        {
            // 冲刺 CD（从 PlayerController 读取 rollCooldown + lastRollTime）
            if (_playerController != null)
            {
                var cdField = typeof(PlayerController).GetField("rollCooldown",
                    System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
                var lastField = typeof(PlayerController).GetField("lastRollTime",
                    System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
                float sprintCD = cdField != null ? (float)cdField.GetValue(_playerController) : 1f;
                float lastRoll = lastField != null ? (float)lastField.GetValue(_playerController) : -999f;
                float remaining = Mathf.Max(0f, (lastRoll + sprintCD) - Time.time);
                UpdateSkillCD(skillSprintCD, remaining, sprintCD);
            }

            // 摇铃 CD（从 EchoSystem 读取 cooldown + _lastEchoTime）
            if (_echoSystem != null)
            {
                var cdField = typeof(EchoSystem).GetField("cooldown",
                    System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
                var lastField = typeof(EchoSystem).GetField("_lastEchoTime",
                    System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
                float bellCD = cdField != null ? (float)cdField.GetValue(_echoSystem) : 2f;
                float lastTime = lastField != null ? (float)lastField.GetValue(_echoSystem) : -999f;
                float remaining = Mathf.Max(0f, (lastTime + bellCD) - Time.time);
                UpdateSkillCD(skillBellCD, remaining, bellCD);
            }

            // 灵灯 CD（从 SpiritLanternSystem 读取）
            if (_lanternSystem != null)
            {
                float remaining = _lanternSystem.CooldownRemaining;
                var cdField = typeof(SpiritLanternSystem).GetField("cooldown",
                    System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
                float maxCD = cdField != null ? (float)cdField.GetValue(_lanternSystem) : 3f;
                UpdateSkillCD(skillLanternCD, remaining, maxCD);
            }
        }

        /// <summary>
        /// 更新单个技能CD遮罩。
        /// fillAmount = 1 表示CD中（完全遮挡），0 表示就绪（无遮挡）。
        /// </summary>
        private void UpdateSkillCD(Image cdImage, float remaining, float total)
        {
            if (cdImage == null) return;

            if (total <= 0f || remaining <= 0f)
            {
                cdImage.fillAmount = 0f;
                cdImage.gameObject.SetActive(false);
            }
            else
            {
                cdImage.gameObject.SetActive(true);
                cdImage.fillAmount = remaining / total;
            }
        }

        private void OnPauseClick()
        {
            if (TimeController.Instance != null)
                TimeController.Instance.Pause();
        }
    }
}