using System.Collections;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.InputSystem;
using UnityEngine.Rendering;
using UnityEngine.SceneManagement;
using OctoRef = OctoCore.OctoCore;

namespace Unheimlich.Navigation.Debuging
{
    /// <summary>
    /// Listens for debug input combos and drives DebugNavigation.
    ///
    /// — Gamepad  : L3+R3 simultaneously → unlock/lock. L2/R2 → prev/next scene.
    /// — Keyboard : backquote (² AZERTY / ~ QWERTY) → unlock/lock. A/E → prev/next.
    ///
    /// Device display: switches based on last active input, not physical connection.
    /// </summary>
    public class DebugMenuUnlocker : MonoBehaviour
    {
        [Header("Data")]
        [SerializeField] private DebugNavigation _debugNavigation;

        [Header("Unlock Events")]
        public UnityEvent OnDebugMenuUnlockedGamepad;
        public UnityEvent OnDebugMenuUnlockedKeyboard;
        public UnityEvent OnDebugMenuLocked;

        [Header("Navigation Events")]
        public UnityEvent OnPreviousScene;
        public UnityEvent OnNextScene;

        [Header("Device Switch Events")]
        [Tooltip("Fired when gamepad input is detected and last input was keyboard/mouse.")]
        public UnityEvent OnSwitchedToGamepad;

        [Tooltip("Fired when keyboard/mouse input is detected and last input was gamepad.")]
        public UnityEvent OnSwitchedToKeyboard;

        // ── State ────────────────────────────────────────────────────────────

        private bool _isUnlocked     = false;
        private bool _lastWasGamepad = false;

        // Input Actions
        private InputAction _keyboardUnlockAction;
        private InputAction _gamepadUnlockAction;
        private InputAction _gamepadPreviousAction;
        private InputAction _gamepadNextAction;
        private InputAction _keyboardPreviousAction;
        private InputAction _keyboardNextAction;
        private InputAction _anyGamepadAction;
        private InputAction _anyKeyboardAction;

        // ── Unity lifecycle ──────────────────────────────────────────────────

        private void Awake()    => BuildInputActions();
        private void OnEnable() => EnableActions();
        private void Start()
        {
            DebugManager.instance.enableRuntimeUI = false;

            StartCoroutine(InitWhenReady());
            SceneManager.sceneLoaded += OnUnitySceneLoaded;
        }
        private void OnDisable()
        {
            DisableActions();
            UnsubscribeFromSceneEvents();
            SceneManager.sceneLoaded -= OnUnitySceneLoaded;
        }
        private void OnDestroy() => DisposeActions();

        // ── Build ────────────────────────────────────────────────────────────

        private void BuildInputActions()
        {
            // Keyboard unlock : backquote (² AZERTY / ~ QWERTY)
            _keyboardUnlockAction = new InputAction("DebugUnlockKeyboard", InputActionType.Button);
            _keyboardUnlockAction.AddBinding("<Keyboard>/backquote");
            _keyboardUnlockAction.performed += _ => ToggleDebugMenu(false);

            // Gamepad unlock : L3 + R3 simultaneously
            _gamepadUnlockAction = new InputAction("DebugUnlockGamepad", InputActionType.Button);
            _gamepadUnlockAction.AddCompositeBinding("ButtonWithOneModifier")
                .With("Modifier", "<Gamepad>/leftStickPress")
                .With("Button",   "<Gamepad>/rightStickPress");
            _gamepadUnlockAction.performed += _ => ToggleDebugMenu(true);

            // Gamepad navigation : L2 / R2
            _gamepadPreviousAction = new InputAction("DebugPrevGamepad", InputActionType.Button);
            _gamepadPreviousAction.AddBinding("<Gamepad>/leftTrigger")
                .WithProcessor("AxisDeadzone(min=0.5,max=1)");
            _gamepadPreviousAction.performed += _ => TryPrevious();

            _gamepadNextAction = new InputAction("DebugNextGamepad", InputActionType.Button);
            _gamepadNextAction.AddBinding("<Gamepad>/rightTrigger")
                .WithProcessor("AxisDeadzone(min=0.5,max=1)");
            _gamepadNextAction.performed += _ => TryNext();

            // Keyboard navigation : A / E
            _keyboardPreviousAction = new InputAction("DebugPrevKeyboard", InputActionType.Button);
            _keyboardPreviousAction.AddBinding("<Keyboard>/q");
            _keyboardPreviousAction.performed += _ => TryPrevious();

            _keyboardNextAction = new InputAction("DebugNextKeyboard", InputActionType.Button);
            _keyboardNextAction.AddBinding("<Keyboard>/e");
            _keyboardNextAction.performed += _ => TryNext();

            // Device detection
            _anyGamepadAction = new InputAction("AnyGamepad", InputActionType.PassThrough);
            _anyGamepadAction.AddBinding("<Gamepad>/leftStick");
            _anyGamepadAction.AddBinding("<Gamepad>/rightStick");
            _anyGamepadAction.AddBinding("<Gamepad>/buttonSouth");
            _anyGamepadAction.AddBinding("<Gamepad>/buttonNorth");
            _anyGamepadAction.AddBinding("<Gamepad>/buttonEast");
            _anyGamepadAction.AddBinding("<Gamepad>/buttonWest");
            _anyGamepadAction.AddBinding("<Gamepad>/leftShoulder");
            _anyGamepadAction.AddBinding("<Gamepad>/rightShoulder");
            _anyGamepadAction.AddBinding("<Gamepad>/leftTrigger");
            _anyGamepadAction.AddBinding("<Gamepad>/rightTrigger");
            _anyGamepadAction.AddBinding("<Gamepad>/start");
            _anyGamepadAction.AddBinding("<Gamepad>/select");
            _anyGamepadAction.AddBinding("<Gamepad>/dpad");
            _anyGamepadAction.performed += _ => OnAnyGamepadInput();

            _anyKeyboardAction = new InputAction("AnyKeyboard", InputActionType.PassThrough);
            _anyKeyboardAction.AddBinding("<Keyboard>/anyKey");
            _anyKeyboardAction.AddBinding("<Mouse>/delta");
            _anyKeyboardAction.AddBinding("<Mouse>/leftButton");
            _anyKeyboardAction.AddBinding("<Mouse>/rightButton");
            _anyKeyboardAction.performed += _ => OnAnyKeyboardInput();
        }

        private void EnableActions()
        {
            _keyboardUnlockAction?.Enable();
            _gamepadUnlockAction?.Enable();
            _gamepadPreviousAction?.Enable();
            _gamepadNextAction?.Enable();
            _keyboardPreviousAction?.Enable();
            _keyboardNextAction?.Enable();
            _anyGamepadAction?.Enable();
            _anyKeyboardAction?.Enable();
        }

        private void DisableActions()
        {
            _keyboardUnlockAction?.Disable();
            _gamepadUnlockAction?.Disable();
            _gamepadPreviousAction?.Disable();
            _gamepadNextAction?.Disable();
            _keyboardPreviousAction?.Disable();
            _keyboardNextAction?.Disable();
            _anyGamepadAction?.Disable();
            _anyKeyboardAction?.Disable();
        }

        private void DisposeActions()
        {
            _keyboardUnlockAction?.Dispose();
            _gamepadUnlockAction?.Dispose();
            _gamepadPreviousAction?.Dispose();
            _gamepadNextAction?.Dispose();
            _keyboardPreviousAction?.Dispose();
            _keyboardNextAction?.Dispose();
            _anyGamepadAction?.Dispose();
            _anyKeyboardAction?.Dispose();
        }

        // ── Init ─────────────────────────────────────────────────────────────

        private IEnumerator InitWhenReady()
        {
            yield return new WaitUntil(() => OctoRef.Instance != null);
            yield return new WaitUntil(() => OctoRef.Instance.Navigation.CurrentScene != null);

            SyncDebugNavigation();
            SubscribeToSceneEvents();
        }

        // ── Scene events ─────────────────────────────────────────────────────

        private void SubscribeToSceneEvents()
        {
            if (OctoRef.Instance == null) return;
            OctoRef.Instance.Navigation.OnSceneLoadCompleted += OnSceneLoadCompleted;
        }

        private void UnsubscribeFromSceneEvents()
        {
            if (OctoRef.Instance == null) return;
            OctoRef.Instance.Navigation.OnSceneLoadCompleted -= OnSceneLoadCompleted;
        }

        private void OnUnitySceneLoaded(Scene scene, LoadSceneMode mode)
        {
            UnsubscribeFromSceneEvents();
            SubscribeToSceneEvents();
        }

        private void OnSceneLoadCompleted(OctoCore.Navigation.Data.OctoSceneData sceneData)
        {
            _debugNavigation?.SyncWithCurrentScene(sceneData);
        }

        // ── Device switch ────────────────────────────────────────────────────

        private void OnAnyGamepadInput()
        {
            if (_lastWasGamepad) return;
            _lastWasGamepad = true;
            OnSwitchedToGamepad?.Invoke();
        }

        private void OnAnyKeyboardInput()
        {
            if (!_lastWasGamepad) return;
            _lastWasGamepad = false;
            OnSwitchedToKeyboard?.Invoke();
        }

        // ── Logic ────────────────────────────────────────────────────────────

        private void SyncDebugNavigation()
        {
            if (_debugNavigation == null || OctoRef.Instance == null) return;
            _debugNavigation.SyncWithCurrentScene(OctoRef.Instance.Navigation.CurrentScene);
        }

        private void ToggleDebugMenu(bool isGamepad)
        {
            _isUnlocked = !_isUnlocked;

            if (_isUnlocked)
            {
                SyncDebugNavigation();
                if (isGamepad) OnDebugMenuUnlockedGamepad?.Invoke();
                else           OnDebugMenuUnlockedKeyboard?.Invoke();
                Debug.Log($"[DebugMenuUnlocker] Unlocked ({(isGamepad ? "Gamepad" : "Keyboard")}).");
            }
            else
            {
                OnDebugMenuLocked?.Invoke();
                Debug.Log("[DebugMenuUnlocker] Locked.");
            }
        }

        private void TryPrevious()
        {
            if (!_isUnlocked || _debugNavigation == null) return;
            OnPreviousScene?.Invoke();
            _debugNavigation.Previous();
        }

        private void TryNext()
        {
            if (!_isUnlocked || _debugNavigation == null) return;
            OnNextScene?.Invoke();
            _debugNavigation.Next();
        }

        /// <summary>Called directly by Debug Menu UI buttons (0-based index).</summary>
        public void LoadSceneByIndex(int index)
        {
            if (_debugNavigation == null) return;
            _debugNavigation.LoadByIndex(index);
        }

        public bool IsUnlocked => _isUnlocked;
    }
}