using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Serialization;
using Utility;

public class Pickupper : MonoBehaviour
{
    [SerializeField] private Character _character;
    
    [SerializeField, Tooltip("Der Radius in dem Gottfried Gegenstände aufheben kann."), Min(0.0f)]
    private float _pickupRadius = 1.5f;

    /// <summary>
    /// Der Radius in dem Gottfried Gegenstände aufheben kann.
    /// </summary>
    public float PickupRadius => _pickupRadius;

    [SerializeField]
    private CapsuleCollider _pickupCollider;

    [SerializeField]
    private List<Pickupable> _pickupablesInRange = new();

    public IReadOnlyList<Pickupable> PickupablesInRange => _pickupablesInRange;

    private int _selectedActionIndex = 0;

    public bool CanSelectPrevious => _selectedActionIndex > 0;
    public bool CanSelectNext => _selectedActionIndex < PickupablesInRange.Count - 1;

    public Pickupable Selected => PickupablesInRange[_selectedActionIndex];
    
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.LeftArrow))
        {
            SelectPreviousAction();
        }
        
        if (Input.GetKeyDown(KeyCode.RightArrow))
        {
            SelectNextAction();
        }

        if (Input.GetKeyDown(KeyCode.E))
        {
            PickUp();
        }
    }

    private void PickUp()
    {
        if (PickupablesInRange.Count == 0)
            return;

        Pickupable pickupable = Selected;
        
        UnhighlightPickupable(pickupable);
        _character.PickupItem(pickupable);
    }

    public void SelectPreviousAction()
    {
        _selectedActionIndex--;
        UpdateSelection();
    }

    public void SelectNextAction()
    {
        _selectedActionIndex++;
        UpdateSelection();
    }

    private void UpdateSelection()
    {
        if (_pickupablesInRange.Count > 0)
        {
            _selectedActionIndex = Math.Clamp(_selectedActionIndex, 0, PickupablesInRange.Count - 1);
        }
        else
        {
            _selectedActionIndex = 0;
        }

        int index = 0;
        foreach (Pickupable pickupable in _pickupablesInRange)
        {
            pickupable.SetSelected(index == _selectedActionIndex);
            index++;
        }
    }
    
    private void OnTriggerEnter(Collider other)
    {
        Pickupable pickupable = other.gameObject.GetComponent<Pickupable>();

        if (pickupable)
        {
            HighlightPickupable(pickupable);
        }
    }
    
    void OnTriggerExit(Collider other)
    {
        Pickupable pickupable = other.gameObject.GetComponent<Pickupable>();

        if (pickupable)
        {
            UnhighlightPickupable(pickupable);
        }
    }

    private void HighlightPickupable(Pickupable pickupable)
    {
        if (!_pickupablesInRange.Contains(pickupable))
            _pickupablesInRange.Add(pickupable);

        pickupable.Highlight(true);
        
        UpdateSelection();
    }
    
    private void UnhighlightPickupable(Pickupable pickupable)
    {
        pickupable.Highlight(false);
        _pickupablesInRange.Remove(pickupable);
        UpdateSelection();
    }

    // Wird aufgerufen, wenn ein Wert im Editor geändert wird
    void OnValidate()
    {
        if (_pickupCollider)
        {
            _pickupCollider.radius = _pickupRadius;
        }
    }
}