using UnityEngine;
using UnityEngine.UIElements;
using OnlyScove.Scripts;
using System.Collections.Generic;
using UnityEngine.InputSystem;

namespace UI
{
    public class HUDController : MonoBehaviour
    {
        [Header("UI Document")]
        public UIDocument hudDocument;

        private VisualElement _healthFill;
        private VisualElement _staminaFill;
        private Label _healthText;
        private VisualElement _interactionPrompt;
        private Label _interactionLabel;

        private VisualElement _statsArea;
        private VisualElement _inventoryArea;
        private VisualElement _infoArea;

        private float _lastInputTime;
        private bool _isHUDVisible = true;
        public float autoHideDelay = 5f;

        private void OnEnable()
        {
            if (hudDocument == null)
                hudDocument = GetComponent<UIDocument>();

            var root = hudDocument.rootVisualElement;

            _healthFill = root.Q<VisualElement>("health-fill");
            _staminaFill = root.Q<VisualElement>("stamina-fill");
            _healthText = root.Q<Label>("health-text");
            _interactionPrompt = root.Q<VisualElement>("interaction-prompt");
            _interactionLabel = root.Q<Label>("interaction-text");

            _statsArea = root.Q<VisualElement>("hud-stats");
            _inventoryArea = root.Q<VisualElement>("hud-inventory");
            _infoArea = root.Q<VisualElement>("hud-info");

            _lastInputTime = Time.time;
        }

        private void Update()
        {
            if (PlayerStateMachine.Local != null)
            {
                SubscribeToPlayer(PlayerStateMachine.Local);
            }

            HandleAutoHide();
            HandleInventoryInput();
        }

        private void HandleAutoHide()
        {
            bool inputDetected = false;

            // Check for mouse movement
            if (Mouse.current != null && Mouse.current.delta.ReadValue().sqrMagnitude > 0.01f)
                inputDetected = true;

            // Check for any key press (including mouse buttons)
            if (!inputDetected && Keyboard.current != null && Keyboard.current.anyKey.isPressed)
                inputDetected = true;
            
            if (!inputDetected && Mouse.current != null && (Mouse.current.leftButton.isPressed || Mouse.current.rightButton.isPressed))
                inputDetected = true;

            if (inputDetected)
            {
                _lastInputTime = Time.time;
                SetHUDVisibility(true);
            }
            else if (Time.time - _lastInputTime > autoHideDelay)
            {
                SetHUDVisibility(false);
            }
        }

        private void SetHUDVisibility(bool visible)
        {
            if (_isHUDVisible == visible) return;
            _isHUDVisible = visible;

            float targetOpacity = visible ? 1f : 0.2f;
            
            _statsArea.style.opacity = targetOpacity;
            _inventoryArea.style.opacity = targetOpacity;
            _infoArea.style.opacity = targetOpacity;

            _statsArea.style.transitionProperty = new List<StylePropertyName> { "opacity" };
            _statsArea.style.transitionDuration = new List<TimeValue> { new TimeValue(0.5f, TimeUnit.Second) };
            _inventoryArea.style.transitionProperty = new List<StylePropertyName> { "opacity" };
            _inventoryArea.style.transitionDuration = new List<TimeValue> { new TimeValue(0.5f, TimeUnit.Second) };
            _infoArea.style.transitionProperty = new List<StylePropertyName> { "opacity" };
            _infoArea.style.transitionDuration = new List<TimeValue> { new TimeValue(0.5f, TimeUnit.Second) };
        }

        private void HandleInventoryInput()
        {
            if (Keyboard.current == null) return;

            if (Keyboard.current.digit1Key.wasPressedThisFrame) SelectSlot(1);
            if (Keyboard.current.digit2Key.wasPressedThisFrame) SelectSlot(2);
            if (Keyboard.current.digit3Key.wasPressedThisFrame) SelectSlot(3);
        }

        private void SelectSlot(int index)
        {
            // Mock logic: Highlight the selected slot
            var root = hudDocument.rootVisualElement;
            for (int i = 1; i <= 3; i++)
            {
                var slot = root.Q<VisualElement>($"slot-{i}");
                if (slot != null)
                {
                    float width = (i == index) ? 2f : 1f;
                    Color color = (i == index) ? Color.white : new Color(0.5f, 0.5f, 0.5f);

                    slot.style.borderTopWidth = width;
                    slot.style.borderBottomWidth = width;
                    slot.style.borderLeftWidth = width;
                    slot.style.borderRightWidth = width;

                    slot.style.borderTopColor = color;
                    slot.style.borderBottomColor = color;
                    slot.style.borderLeftColor = color;
                    slot.style.borderRightColor = color;
                }
            }
            _lastInputTime = Time.time;
            SetHUDVisibility(true);
        }

        private PlayerStateMachine _currentPlayer;

        private void SubscribeToPlayer(PlayerStateMachine player)
        {
            if (_currentPlayer == player) return;

            if (_currentPlayer != null)
            {
                _currentPlayer.OnHealthChanged -= UpdateHealth;
                _currentPlayer.OnStaminaChanged -= UpdateStamina;
                _currentPlayer.OnInteractableTargetChanged -= UpdateInteraction;
            }

            _currentPlayer = player;

            _currentPlayer.OnHealthChanged += UpdateHealth;
            _currentPlayer.OnStaminaChanged += UpdateStamina;
            _currentPlayer.OnInteractableTargetChanged += UpdateInteraction;

            UpdateHealth(_currentPlayer.Health);
            UpdateStamina(_currentPlayer.Stamina);
        }

        private void UpdateHealth(float health)
        {
            if (_healthFill != null) _healthFill.style.width = Length.Percent(health);
            _lastInputTime = Time.time;
            SetHUDVisibility(true);
        }

        private void UpdateStamina(float stamina)
        {
            if (_staminaFill != null) _staminaFill.style.width = Length.Percent(stamina);
            if (stamina < 99f) // Only wake up HUD if stamina is being used
            {
                _lastInputTime = Time.time;
                SetHUDVisibility(true);
            }
        }

        private void UpdateInteraction(IInteractable interactable)
        {
            if (_interactionPrompt == null) return;

            if (interactable != null)
            {
                _interactionPrompt.style.display = DisplayStyle.Flex;
                if (_interactionLabel != null) _interactionLabel.text = interactable.InteractionPrompt;
                _lastInputTime = Time.time;
                SetHUDVisibility(true);
            }
            else
            {
                _interactionPrompt.style.display = DisplayStyle.None;
            }
        }
    }
}