using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;
using UnityEngine.EventSystems;

// TODO: Expand for other measurement systems later


namespace SimpleInventorySystem
{
    public enum Orientation { Portrait, Landscape };

    [Serializable]
    public struct Size
    {
        public int Width;
        public int Height;

        public Size(int width, int height)
        {
            this.Width = width;
            this.Height = height;
        }
        public Size(float width, float height)
        {
            this.Width = (int)width;
            this.Height = (int)height;
        }

        public int span { get { return Width * Height; } }
    }

    public struct KeyInput
    {
        public bool pressedKey, holdingKey;
        public KeyCode keyCode;

        public KeyInput(KeyCode keyCode)
        {
            this.keyCode = keyCode;
            pressedKey = false;
            holdingKey = false;
        }
        public void Update()
        {
            if (Input.GetKeyDown(keyCode) && !pressedKey && !holdingKey)
            {
                //Debug.Log("R");
                pressedKey = true;
            }
            else if (pressedKey && !holdingKey)
            {
                holdingKey = true;
            }
            else if (Input.GetKeyUp(keyCode))
            {
                //Debug.Log("R - up");
                holdingKey = false;
                pressedKey = false;
            }
        }

        public bool PressedKey(bool singlePress)
        {
            return pressedKey && (!singlePress || !holdingKey);
        }
    }

    public enum ItemTags
    {
        Any,
        Helmet,
        Headset,
        Glasses,
        FaceCover,
        Plate,
        Weapon,
        Sidearm,
        MeleeWeapon,
        TacticalRig,
        TacticalRigAttachment,
        MedPouch,
        Backpack,
        Pouch1x1,
        Pouch1x2,
        Pouch1x3,
        Pouch2x2,
        BodyArmor
    }

    public class InventorySystem : MonoBehaviour, IPointerClickHandler
    {
        [SerializeField] private string[] RaritySystemUnits;
        private string[] weightSystemUnitsSymbols;
        [SerializeField] private string[] weightSystemUnits;
        [SerializeField] private float[] currencySystemUnits;
        [SerializeField] private string[] currencySystemUnitsSymbols;
        public static InventorySystem instance;
        public Canvas inventoryUI;
        public Canvas playerUI;
        private TextMeshProUGUI lootMessage;
        public GameObject InventoryMenuUI;
        public GameObject LootMenuUI;
        public GameObject StatsMenuUI;
        public KeyCode rotateKey;
        public KeyCode menuKey;
        public KeyCode interactKey;
        protected KeyInput rotationKeyInput;
        protected KeyInput menuKeyInput;
        protected KeyInput interactKeyInput;
        [SerializeField] private int DefaultWidthOnGrid = 100;
        [SerializeField] private int DefaultHeightOnGrid = 100;
        public Size DefaultSizeOnGrid;
        public Camera playerCamera;
        public GameObject EventsObject;
        private GameObject toolbarEvents;
        public StandaloneInputModule StandaloneInputModule;
        public Vector2 MouseInCanvasPosition;
        public ItemUI DraggedItem;
        public ContextMenuManagerUI ContextMenuUI;
        public static List<GameObject> hoverResults;

        private void Awake()
        {
            if (instance == null)
            {
                instance = this;
            }
            else
            {
                // TODO: Test this, make sure only one inventory system is active throughout the game
                Destroy(gameObject);
            }
            DefaultSizeOnGrid = new Size(DefaultWidthOnGrid, DefaultHeightOnGrid);

            rotationKeyInput = new KeyInput(rotateKey);
            menuKeyInput = new KeyInput(menuKey);
            interactKeyInput = new KeyInput(interactKey);

            lootMessage = playerUI.transform.Find("Loot Message").GetComponent<TextMeshProUGUI>();
            if (lootMessage != null)
            {
                string text = lootMessage.text;
                if (text.Contains("{key:interactKey}"))
                    lootMessage.text = lootMessage.text.Replace("{key:interactKey}", "[ " + interactKey.ToString() + " ]");
            }

            toolbarEvents = EventsObject.transform.Find("Toolbar").gameObject;

            InventoryMenuUI.SetActive(false);
        }

        // Start is called before the first frame update
        void Start()
        {
        }

        // Update is called once per frame
        void Update()
        {
            rotationKeyInput.Update();
            menuKeyInput.Update();
            interactKeyInput.Update();

            DetectObject();

            if (menuKeyInput.PressedKey(true))
            {
                if(InventoryMenuUI != null)
                {
                    ToggleInventory();
                }
            }

            hoverResults = GetPointerOverUIObject();
        }

        private List<GameObject> GetPointerOverUIObject()
        {
            PointerEventData eventDataCurrentPosition = new PointerEventData(EventSystem.current);
            eventDataCurrentPosition.position = new Vector2(Input.mousePosition.x, Input.mousePosition.y);
            List<RaycastResult> results = new List<RaycastResult>();
            EventSystem.current.RaycastAll(eventDataCurrentPosition, results);
            List<GameObject> rGOs = new List<GameObject>();
            for (int i = 0; i < results.Count; i++)
            {
                if (results[i].gameObject.layer == LayerMask.GetMask("Ignore Raycast"))
                {
                    results.RemoveAt(i);
                    i--;
                }
                else// if (results[i].gameObject.layer == LayerMask.GetMask("UI"))
                {
                    rGOs.Add(results[i].gameObject);
                }
            }

            return rGOs;
        }

        public static bool IsMouseOverUI(GameObject go)
        {
            if(hoverResults == null || hoverResults.Count == 0)
            {
                return false;
            }
            return hoverResults.Contains(go);
        }
        public static bool IsMouseOverItemUITop(ItemUI item)
        {
            if (hoverResults == null || hoverResults.Count == 0)
            {
                return false;
            }
            foreach(GameObject go in hoverResults)
            {
                if(go.GetComponent<ItemUI>() != null)
                {
                    if (go.GetComponent<ItemUI>() == item)
                        return true;
                    else
                        return false;
                }
            }
            return false;
        }

        private void FixedUpdate()
        {
            Vector2 movePos;
            RectTransformUtility.ScreenPointToLocalPointInRectangle(inventoryUI.transform as RectTransform, Input.mousePosition, inventoryUI.worldCamera, out movePos);

            MouseInCanvasPosition = InventorySystem.instance.inventoryUI.transform.TransformPoint(movePos);
        }

        public void ToggleInventory()
        {
            if (InventoryMenuUI.activeInHierarchy)
            {
                CloseInventory();
            }
            else
            {
                OpenInventory();
            }
        }

        public void OpenInventory()
        {
            InventoryMenuUI.SetActive(true);
            toolbarEvents.GetComponent<MoveChildrenUI>().MoveToTarget(false, true);
        }
        public void CloseInventory()
        {
            toolbarEvents.GetComponent<MoveChildrenUI>().MoveToSource(true, false); 
            InventoryMenuUI.SetActive(false);
        }


        public void OpenContextMenu(MonoBehaviour uiContext)
        {
            if (uiContext.GetType() == typeof(ItemUI))
            {
                ContextMenuUI.OpenContextMenu((ItemUI)uiContext);
            }
        }

        private void DetectObject()
        {
            if (playerCamera == null)
            {
                //Debug.Log("Uh OHHH. No camera detected");
            }
            else
            {
                //Debug.Log("Detecting...");
            }
            Ray ray = playerCamera.ScreenPointToRay(new Vector2(Screen.width / 2, Screen.height / 2));//controls.Mouse.Position.ReadValue<Vector2>());
            RaycastHit hit;
            if (Physics.Raycast(ray, out hit))
            {
                if (hit.collider != null)// && hit.transform.parent.parent.parent != null)
                {
                    //Debug.Log("3D Hit: " + hit.collider.transform.name);
                    // TODO: functionality here

                    Inventory response = hit.collider.transform.GetComponent<Inventory>();
                    if (response != null && !InventorySystem.instance.IsUsingInventoryMenuUI())
                    {
                        if (interactKeyInput.PressedKey(true))
                        {
                            OpenInventory();
                            LootMenuUI.SetActive(true);
                            StatsMenuUI.SetActive(false);
                            lootMessage.gameObject.SetActive(false);
                        }
                        else if (!InventorySystem.instance.IsUsingInventoryMenuUI())
                        {
                            lootMessage.gameObject.SetActive(true);
                        }
                    }
                    else if(!InventorySystem.instance.IsUsingInventoryMenuUI())
                    {
                        lootMessage.gameObject.SetActive(false);
                        LootMenuUI.SetActive(false);
                        StatsMenuUI.SetActive(true);
                    }
                }
            }

            /*RaycastHit[] hits = Physics.RaycastAll(ray, 200);
            for(int i = 0; i < hits.Length; i++)
            {
                if (hits[i].collider != null)
                {
                    Debug.Log("3D Hit All: " + hits[i].collider.tag);
                }
            }*/

            /*RaycastHit[] hitsNonAlloc = new RaycastHit[1];
            int numberOfHits = Physics.RaycastNonAlloc(ray, hitsNonAlloc);
            for (int i = 0; i < numberOfHits; i++)
            {
                if (hitsNonAlloc[i].collider != null)
                {
                    Debug.Log("3D Hit Non Alloc All: " + hitsNonAlloc[i].collider.tag);
                }
            }*/
        }

        /// <summary>
        /// This can  be called to check if player is interacting with the Inventory System's UI
        /// </summary>
        /// <returns></returns>
        public bool IsUsingInventoryMenuUI()
        {
            return InventoryMenuUI.activeInHierarchy;
        }

        public bool PressedKeyRotation(bool singlePress)
        {
            return rotationKeyInput.PressedKey(singlePress);
        }

        public void OnPointerClick(PointerEventData eventData)
        {
        }
    }
}