using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace SimpleInventorySystem
{
    [RequireComponent(typeof(Collider))]
    public class PickUp : MonoBehaviour
    {
        public GameObject ItemGameObject;
        public Vector3 alterPosition;
        public Vector3 alterRotation;
        public Vector3 alterScale = Vector3.one;
        private Vector3 oldPosition;
        private Vector3 oldRotation;
        private Vector3 oldScale;
        public ItemUI itemUI;
        private Collider pickUpCollider;
        public PickUpRange pickUpRange;
        public bool HadPickedUp { private set; get; }
        [HideInInspector] public TargetAttachment targetAttachment;
        public SlotUI PlaceInContainerOfItemInSlot;

        // Start is called before the first frame update
        void Start()
        {
            pickUpCollider = GetComponent<Collider>();
            if (!pickUpCollider.isTrigger)
            {
                Debug.LogWarning("PickUp: The collider should be a trigger.");
            }

            if(ItemGameObject == null)
            {
                Debug.LogError("PickUp: ItemGameObject should not be null.");
            }

            oldPosition = ItemGameObject.transform.localPosition;
            oldRotation = ItemGameObject.transform.localRotation.eulerAngles;
            oldScale = ItemGameObject.transform.localScale;

            //itemUI = Item.GetComponent<ItemUI>();
            if (itemUI == null)
            {
                Debug.LogError("PickUp: ItemUI must not be null.");
            }
            else
            {
                itemUI.pickUp = this;
            }

            pickUpRange = GetComponentInChildren<PickUpRange>();
            if(pickUpRange == null)
            {
                Debug.LogError("PickUp: PickUpRange must not be null.");
            }
            else
            {
                pickUpRange.pickUp = this;
            }

        }

        public void SetItemGameObjectTransform(Vector3 newPosition, Vector3 newRotation, Vector3 newScale)
        {
            ItemGameObject.transform.localPosition = newPosition;
            ItemGameObject.transform.localRotation = Quaternion.Euler(newRotation);
            ItemGameObject.transform.localScale = newScale;
        }

        public void DropDownHandler(bool keepOldPosition = false)
        {
            if(keepOldPosition)
                ItemGameObject.transform.localPosition = oldPosition;
            ItemGameObject.transform.localRotation = Quaternion.Euler(oldRotation);
            ItemGameObject.transform.localScale = oldScale;
            HadPickedUp = false;
            pickUpCollider.enabled = true;
            pickUpRange.GetComponent<Collider>().enabled = true;
        }

        public void AlterItemGameObjectTransform()
        {
            ItemGameObject.transform.localPosition = alterPosition;
            ItemGameObject.transform.localRotation = Quaternion.Euler(alterRotation);
            if(alterScale != Vector3.zero && alterScale.x != 0 && alterScale.y != 0 && alterScale.z != 0)
                ItemGameObject.transform.localScale = alterScale;
            else
            {
                ItemGameObject.transform.localScale = Vector3.one;
            }
        }

        public void PickUpHandler()
        {
            if (!HadPickedUp)
            {
                foreach (TagSlotPairing tsp in InventorySystem.instance.TagSlotPairings)
                {
                    if (!tsp.HasSlotOccupied())
                    {
                        bool dropped = tsp.slot.DropOntoSlot(itemUI.gameObject);
                        if (dropped)
                        {
                            itemUI.transform.localRotation = Quaternion.Euler(new Vector3());
                            itemUI.transform.localScale = new Vector3(1, 1, 1);
                            HadPickedUp = true;

                            // TODO: Handle changing transform here
                            //ItemGameObject.GetComponent<>;

                            if(InventorySystem.instance.player.AttachItemGameObject(ItemGameObject, itemUI.ItemTag, itemUI))
                            {
                                pickUpCollider.enabled = false;
                                pickUpRange.GetComponent<Collider>().enabled = false;
                            }
                        }
                    }
                }

                // assume there is no tsp, then try to drop in most available backpack slot
                if (PlaceInContainerOfItemInSlot != null)
                {
                    if (PlaceInContainerOfItemInSlot.GetItemUI() != null && PlaceInContainerOfItemInSlot.GetItemUI().container != null)
                    {
                        GridUI grid = PlaceInContainerOfItemInSlot.GetItemUI().container.GetComponent<GridUI>();
                        if (grid != null)
                        {
                            if (grid.DropItemOnGrid(itemUI.gameObject))
                            {
                                Debug.Log("PickUp: Placed in grid.");
                                HadPickedUp = true;

                                // TODO: Handle changing transform here
                                //ItemGameObject.GetComponent<>;

                                if (InventorySystem.instance.player.AttachItemGameObject(ItemGameObject, itemUI.ItemTag, itemUI))
                                {
                                    pickUpCollider.enabled = false;
                                    pickUpRange.GetComponent<Collider>().enabled = false;
                                }
                                return;
                            }
                        }
                    }
                }

                Debug.Log("Could not pick up");
            }
        }

        // Update is called once per frame
        void Update()
        {

        }
    }

}