using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using Interaction;
using JetBrains.Annotations;
using UnityEngine;
using UnityEngine.Serialization;
using Utility;

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

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

    [FormerlySerializedAs("_pickupCollider")] [SerializeField]
    private CapsuleCollider _interactionCollider;

    [FormerlySerializedAs("_pickupablesInRange")] [SerializeField]
    private List<Interactible> _interactionsInRange = new();

    public IReadOnlyList<Interactible> InteractionsInRange => _interactionsInRange;

    private int _selectedActionIndex = 0;

    public Interactible SelectedAction
    {
        get
        {
            FixSelection();

            return _selectedActionIndex == -1 ? null : InteractionsInRange[_selectedActionIndex];
        }
    }

    void Update()
    {
        if (Input.GetKeyDown(KeyCode.LeftArrow))
        {
            SelectPreviousAction();
        }
        
        if (Input.GetKeyDown(KeyCode.RightArrow))
        {
            SelectNextAction();
        }

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

    private void DoInteraction()
    {
        if (InteractionsInRange.Count == 0)
            return;

        Interactible interactible = SelectedAction;

        if (interactible.IsBlocked())
        {
            _character.SayItsImpossible();
            return;
        }
        
        switch (interactible)
        {
            case PickupInteractible pickup:
                UnhighlightPickupable(interactible);
                _character.PickupItem(pickup);
                break;
            case UseInteractible usable:
                usable.OnUse?.Invoke();
                break;
            case GiveItemInteractible giveItemAction:
                _character.GiveItemTo(giveItemAction.Developer);
                break;
        }
    }

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

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

    private void FixSelection()
    {
        if (_interactionsInRange.Count == 0)
        {
            _selectedActionIndex = -1;
        }
        else
        {
            if (_selectedActionIndex < 0)
                _selectedActionIndex = InteractionsInRange.Count - 1;
            else if (_selectedActionIndex >= InteractionsInRange.Count)
                _selectedActionIndex = 0;
        }
    }

    private void UpdateSelection()
    {
        FixSelection();
        
        int index = 0;
        foreach (Interactible pickupable in _interactionsInRange)
        {
            pickupable.SetSelected(index == _selectedActionIndex);
            index++;
        }
    }
    
    private void OnTriggerEnter(Collider other)
    {
        Interactible interactible = other.gameObject.GetComponent<Interactible>();

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

        if (interactible)
        {
            UnhighlightPickupable(interactible);
        }
    }

    private void HighlightPickupable(Interactible interactible)
    {
        if (!_interactionsInRange.Contains(interactible))
            _interactionsInRange.Add(interactible);

        interactible.Highlight(true);
        
        UpdateSelection();
    }
    
    private void UnhighlightPickupable(Interactible interactible)
    {
        interactible.Highlight(false);
        _interactionsInRange.Remove(interactible);
        
        UpdateSelection();
    }

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