using UnityEngine;

namespace KirbyAdventures
{
    /// <summary>
    /// Global game state: pause, win, light ability unlock.
    /// </summary>
    public class GameFlow : MonoBehaviour
    {
        public static GameFlow Instance { get; private set; }

        public bool IsPaused { get; private set; }
        public bool HasWon { get; private set; }
        public bool LightAbilityUnlocked { get; private set; }

        GameObject _pauseOverlay;
        GameObject _winOverlay;

        void Awake()
        {
            if (Instance != null && Instance != this)
            {
                Destroy(gameObject);
                return;
            }

            Instance = this;
            DontDestroyOnLoad(gameObject);
        }

        public void SetPauseOverlay(GameObject overlay) => _pauseOverlay = overlay;
        public void SetWinOverlay(GameObject overlay) => _winOverlay = overlay;

        public void UnlockLightAbility()
        {
            LightAbilityUnlocked = true;
            Debug.Log("[GameFlow] Light ability unlocked.");
        }

        public void TogglePause()
        {
            if (HasWon) return;
            SetPaused(!IsPaused);
        }

        public void SetPaused(bool paused)
        {
            IsPaused = paused;
            Time.timeScale = paused ? 0f : 1f;
            if (_pauseOverlay != null)
                _pauseOverlay.SetActive(paused);

            Cursor.lockState = paused ? CursorLockMode.None : CursorLockMode.Locked;
            Cursor.visible = paused;
        }

        public void TriggerWin()
        {
            if (HasWon) return;
            HasWon = true;
            IsPaused = true;
            Time.timeScale = 0f;
            if (_winOverlay != null)
                _winOverlay.SetActive(true);
            Cursor.lockState = CursorLockMode.None;
            Cursor.visible = true;
            Debug.Log("[GameFlow] Level complete — village gate opened.");
        }

        void Update()
        {
            var kb = UnityEngine.InputSystem.Keyboard.current;
            if (kb != null && kb.escapeKey.wasPressedThisFrame)
                TogglePause();
        }

        void OnDestroy()
        {
            if (Instance == this)
            {
                Time.timeScale = 1f;
                Instance = null;
            }
        }
    }
}