using System;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.InputSystem;
using UnityEngine.SceneManagement;
using AppleHills.Core.Settings; // Added for IInteractionSettings

namespace Input
{
    public enum InputMode
    {
        Game,
        UI,
        GameAndUI,
        InputDisabled
    }
    
    /// <summary>
    /// Handles input events and dispatches them to the appropriate ITouchInputConsumer.
    /// Supports tap and hold/drag logic, with interactable delegation and debug logging.
    /// </summary>
    public class InputManager : MonoBehaviour
    {
        private const string UiActions = "UI";
        private const string GameActions = "PlayerTouch";
        
        private static InputManager _instance;
        private static bool _isQuitting = false;

        public static InputManager Instance
        {
            get
            {
                if (_instance == null && Application.isPlaying && !_isQuitting)
                {
                    _instance = FindAnyObjectByType<InputManager>();
                    if (_instance == null)
                    {
                        var go = new GameObject("InputManager");
                        _instance = go.AddComponent<InputManager>();
                        // DontDestroyOnLoad(go);
                    }
                }
                return _instance;
            }
        }

        // Settings reference
        private IInteractionSettings _interactionSettings;
        
        private PlayerInput playerInput;
        private InputAction tapMoveAction;
        private InputAction holdMoveAction;
        private InputAction positionAction;
        private ITouchInputConsumer defaultConsumer;
        private bool isHoldActive;

        void Awake()
        {
            _instance = this;
            // DontDestroyOnLoad(gameObject);
            
            // Initialize settings reference
            _interactionSettings = GameManager.GetSettingsObject<IInteractionSettings>();
            
            playerInput = GetComponent<PlayerInput>();
            if (playerInput == null)
            {
                Debug.LogError("[InputManager] InputManager requires a PlayerInput component attached to the same GameObject.");
                return;
            }
            tapMoveAction = playerInput.actions.FindAction("TapMove", false);
            holdMoveAction = playerInput.actions.FindAction("HoldMove", false);
            positionAction = playerInput.actions.FindAction("TouchPosition", false);
        }

        private void Start()
        {
            // SceneManagerService.Instance.SceneLoadCompleted += SwitchInputOnSceneLoaded;
            SwitchInputOnSceneLoaded(SceneManager.GetActiveScene().name);
        }

        private void SwitchInputOnSceneLoaded(string sceneName)
        {
            if (sceneName.ToLower().Contains("mainmenu"))
            {
                Debug.Log("[InputManager] SwitchInputOnSceneLoaded - Setting InputMode to UI for MainMenu");
                SetInputMode(InputMode.UI);
            }
            else
            {
                Debug.Log("[InputManager] SwitchInputOnSceneLoaded - Setting InputMode to PlayerTouch");
                SetInputMode(InputMode.GameAndUI);
            }
        }

        public void SetInputMode(InputMode inputMode)
        {
            switch (inputMode)
            {
                case InputMode.UI:
                    playerInput.actions.FindActionMap(UiActions).Enable();
                    playerInput.actions.FindActionMap(GameActions).Disable();
                    break;
                case InputMode.Game:
                    playerInput.actions.FindActionMap(UiActions).Disable();
                    playerInput.actions.FindActionMap(GameActions).Enable();
                    break;
                case InputMode.GameAndUI:
                    playerInput.actions.FindActionMap(UiActions).Enable();
                    playerInput.actions.FindActionMap(GameActions).Enable();
                    break;
                case InputMode.InputDisabled:
                    playerInput.actions.FindActionMap(UiActions).Disable();
                    playerInput.actions.FindActionMap(GameActions).Disable();
                    break;
            }
        }
        
        void OnEnable()
        {
            if (tapMoveAction != null)
                tapMoveAction.performed += OnTapMovePerformed;
            if (holdMoveAction != null)
            {
                holdMoveAction.performed += OnHoldMoveStarted;
                holdMoveAction.canceled += OnHoldMoveCanceled;
            }
        }

        void OnDisable()
        {
            if (tapMoveAction != null)
                tapMoveAction.performed -= OnTapMovePerformed;
            if (holdMoveAction != null)
            {
                holdMoveAction.performed -= OnHoldMoveStarted;
                holdMoveAction.canceled -= OnHoldMoveCanceled;
            }
        }

        void OnApplicationQuit()
        {
            _isQuitting = true;
        }

        /// <summary>
        /// Sets the default ITouchInputConsumer to receive input events.
        /// </summary>
        public void SetDefaultConsumer(ITouchInputConsumer consumer)
        {
            defaultConsumer = consumer;
        }

        /// <summary>
        /// Handles tap input, delegates to interactable if present, otherwise to default consumer.
        /// </summary>
        private void OnTapMovePerformed(InputAction.CallbackContext ctx)
        {
            if (EventSystem.current.IsPointerOverGameObject())
            {
                return;
            }
            
            Vector2 screenPos = positionAction.ReadValue<Vector2>();
            Vector3 worldPos = Camera.main.ScreenToWorldPoint(screenPos);
            Vector2 worldPos2D = new Vector2(worldPos.x, worldPos.y);
            Debug.Log($"[InputManager] TapMove performed at {worldPos2D}");
            if (!TryDelegateToInteractable(worldPos2D))
            {
                Debug.Log("[InputManager] No interactable found, forwarding tap to default consumer");
                defaultConsumer?.OnTap(worldPos2D);
            }
            else
            {
                Debug.Log("[InputManager] Tap delegated to interactable");
            }
        }

        /// <summary>
        /// Handles the start of a hold input.
        /// </summary>
        private void OnHoldMoveStarted(InputAction.CallbackContext ctx)
        {
            isHoldActive = true;
            Vector2 screenPos = positionAction.ReadValue<Vector2>();
            Vector3 worldPos = Camera.main.ScreenToWorldPoint(screenPos);
            Vector2 worldPos2D = new Vector2(worldPos.x, worldPos.y);
            Debug.Log($"[InputManager] HoldMove started at {worldPos2D}");
            defaultConsumer?.OnHoldStart(worldPos2D);
        }

        /// <summary>
        /// Handles the end of a hold input.
        /// </summary>
        private void OnHoldMoveCanceled(InputAction.CallbackContext ctx)
        {
            if (!isHoldActive) return;
            isHoldActive = false;
            Vector2 screenPos = positionAction.ReadValue<Vector2>();
            Vector3 worldPos = Camera.main.ScreenToWorldPoint(screenPos);
            Vector2 worldPos2D = new Vector2(worldPos.x, worldPos.y);
            Debug.Log($"[InputManager] HoldMove canceled at {worldPos2D}");
            defaultConsumer?.OnHoldEnd(worldPos2D);
        }

        /// <summary>
        /// Continuously updates hold move input while active.
        /// </summary>
        void Update()
        {
            if (isHoldActive && holdMoveAction != null && holdMoveAction.phase == InputActionPhase.Performed)
            {
                Vector2 screenPos = positionAction.ReadValue<Vector2>();
                Vector3 worldPos = Camera.main.ScreenToWorldPoint(screenPos);
                Vector2 worldPos2D = new Vector2(worldPos.x, worldPos.y);
                // Debug.Log($"[InputManager] HoldMove update at {worldPos2D}");
                defaultConsumer?.OnHoldMove(worldPos2D);
            }
        }

        /// <summary>
        /// Attempts to delegate a tap to an interactable at the given world position.
        /// Traces on the "Interactable" channel and logs detailed info.
        /// </summary>
        private bool TryDelegateToInteractable(Vector2 worldPos)
        {
            LayerMask mask = _interactionSettings != null ? _interactionSettings.InteractableLayerMask : -1;
            Collider2D hit = Physics2D.OverlapPoint(worldPos, mask);
            if (hit != null)
            {
                var consumer = hit.GetComponent<ITouchInputConsumer>();
                if (consumer != null)
                {
                    Debug.unityLogger.Log("Interactable", $"[InputManager] Delegating tap to consumer at {worldPos} (GameObject: {hit.gameObject.name})");
                    consumer.OnTap(worldPos);
                    return true;
                }
                Debug.unityLogger.Log("Interactable", $"[InputManager] Collider2D hit at {worldPos} (GameObject: {hit.gameObject.name}), but no ITouchInputConsumer found.");
            }
            else
            {
                Debug.unityLogger.Log("Interactable", $"[InputManager] No Collider2D found at {worldPos} for interactable delegation.");
            }
            return false;
        }
    }
}