using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using UnityEngine;
using System;
using UnityEngine.UI;
using TMPro;

//things to do (for the authur only):
//check if this class is very reusable
//implement a proper way to destroy grids
//add more debug features and controls
//test this in 3D (using x and z axis)
//remove all mentions of  real names in this class and replace them with screen names

//this is Wong Sui Bin's grid class, I advise not to touch this if you are not the authur of this class
//this is a class that greats a 2D grid in the game world that maps with real coordinates
//requires text mesh pro to work

//so far used for
//level editors
//tile based building system
//grid reresentation of positions of game objects
namespace Lemon.GenericLib.Generics
{
    public class Grid<TGridObject>
    {
        public event EventHandler<OnGridObjectChangedArgs> OnGridObjectChanged;

        public class OnGridObjectChangedArgs : EventArgs
        {
            public int x, y;
        }


        public int width;
        public int height;
        private float cellSize;
        private Vector3 originPosition;
        private TGridObject[,] gridArray;
        private TextMeshPro[,] gridText;

        private Color textColour;
        private bool showText;
        private int textSize;
        private bool spawnText;
        private bool debugLine;

        #region constructors
        //arrangement of y is up and x is right
        //grid constructor for custom data types
        public Grid(int width, int height, float cellSize, Vector3 originPosition, Transform parent, Func<Grid<TGridObject>, int, int, TGridObject> createGridObject, bool spawnText = true, bool debugLine = true)
        {
            this.width = width;
            this.height = height;
            this.cellSize = cellSize;
            this.gridArray = new TGridObject[width, height];
            this.gridText = new TextMeshPro[width, height];
            this.originPosition = originPosition;
            this.textColour = Color.white;
            this.showText = true;
            this.textSize = 5;
            this.spawnText = spawnText;
            this.debugLine = debugLine;

            //construct grid object
            for (int x = 0; x < gridArray.GetLength(0); x++)
            {
                for (int y = 0; y < gridArray.GetLength(1); y++)
                {
                    gridArray[x, y] = createGridObject(this, x, y);
                }
            }

            //set debug visuals
            for (int x = 0; x < gridArray.GetLength(0); x++)
            {
                for (int y = 0; y < gridArray.GetLength(1); y++)
                {
                    if (debugLine)
                    {
                        Debug.DrawLine(GetWorldPosition(x, y), GetWorldPosition(x, y + 1), Color.white, 100f);
                        Debug.DrawLine(GetWorldPosition(x, y), GetWorldPosition(x + 1, y), Color.white, 100f);

                    }


                    if (spawnText)
                        gridText[x, y] = CreateGridText(gridArray[x, y]?.ToString(), parent, x, y, GetWorldPositionCenter(x, y), textSize, textColour, TMPro.TextAlignmentOptions.CenterGeoAligned);

                    //disable text if configured to not show
                    gridText[x, y]?.gameObject.SetActive(showText);
                }


            }
            if (debugLine)
            {
                Debug.DrawLine(GetWorldPosition(0, height), GetWorldPosition(width, height), Color.white, 100f);
                Debug.DrawLine(GetWorldPosition(width, 0), GetWorldPosition(width, height), Color.white, 100f);
            }

            //assign object changed even for debug visuals
            OnGridObjectChanged += (object sender, OnGridObjectChangedArgs eventArgs) =>
            {
                gridText[eventArgs.x, eventArgs.y].text = gridArray[eventArgs.x, eventArgs.y].ToString();
            };
        }

        //grid constructor for non custom data type
        public Grid(int width, int height, float cellSize, Vector3 originPosition, Transform parent, bool spawnText = true, bool debugLine = true)
        {
            this.width = width;
            this.height = height;
            this.cellSize = cellSize;
            this.gridArray = new TGridObject[width, height];
            this.gridText = new TextMeshPro[width, height];
            this.originPosition = originPosition;
            this.textColour = Color.white;
            this.showText = true;
            this.textSize = 5;
            this.spawnText = spawnText;
            this.debugLine = debugLine;

            //set debug visuals
            for (int x = 0; x < gridArray.GetLength(0); x++)
            {
                for (int y = 0; y < gridArray.GetLength(1); y++)
                {
                    if (debugLine)
                    {
                        Debug.DrawLine(GetWorldPosition(x, y), GetWorldPosition(x, y + 1), Color.white, 100f);
                        Debug.DrawLine(GetWorldPosition(x, y), GetWorldPosition(x + 1, y), Color.white, 100f);

                    }

                    if (spawnText)
                        gridText[x, y] = CreateGridText(gridArray[x, y]?.ToString(), parent, x, y, GetWorldPositionCenter(x, y), textSize, textColour, TMPro.TextAlignmentOptions.CenterGeoAligned);

                    //disable text if configured to not show
                    gridText[x, y]?.gameObject.SetActive(showText);
                }


            }
            if (debugLine)
            {
                Debug.DrawLine(GetWorldPosition(0, height), GetWorldPosition(width, height), Color.white, 100f);
                Debug.DrawLine(GetWorldPosition(width, 0), GetWorldPosition(width, height), Color.white, 100f);
            }
            //assign object changed even for debug visuals
            OnGridObjectChanged += (object sender, OnGridObjectChangedArgs eventArgs) =>
            {
                gridText[eventArgs.x, eventArgs.y].text = gridArray[eventArgs.x, eventArgs.y].ToString();
            };
        }
        #endregion

        #region position hash
        //the hash index for the grid, start from 0 in the bottom left cell and counting right and upwards
        //hash the ridArray position into hash index
        public int positionHash(int x, int y)
        {
            return y * width + x;
        }

        //hash the index back to gridArray position
        public void positionHash(int index, out int x, out int y)
        {
            y = index / width;
            x = index % width;
        }
        #endregion

        #region Get Positions
        //get world posisiton of a corner of a cell
        private Vector3 GetWorldPosition(int x, int y)
        {
            return new Vector3(x, y) * cellSize + originPosition;
        }

        //get world positon of the center of a cell
        public Vector3 GetWorldPositionCenter(int x, int y)
        {
            return GetWorldPosition(x, y) + new Vector3(cellSize, cellSize) * .5f;
        }

        //convert a vector 3 position to the center of a grid
        public Vector3 GetWorldPositionCenter(Vector3 worldPosition)
        {
            int x, y;
            GetXY(worldPosition, out x, out y);
            return GetWorldPositionCenter(x, y);

        }

        //get x and y of grid from world posistion
        public void GetXY(Vector3 worldPosition, out int x, out int y)
        {
            x = Mathf.FloorToInt((worldPosition - originPosition).x / cellSize);
            y = Mathf.FloorToInt((worldPosition - originPosition).y / cellSize);
        }

        public Vector2Int GetXYVector2Int(Vector3 worldPosition)
        {
            return new Vector2Int(Mathf.FloorToInt((worldPosition - originPosition).x / cellSize), Mathf.FloorToInt((worldPosition - originPosition).y / cellSize));
        }
        #endregion

        #region Grid Object Manipulation
        //set value from x and y of the array
        public void SetGridObject(int x, int y, TGridObject gridObject)
        {
            if (x >= 0 && x < width && y >= 0 && y < height)
            {
                gridArray[x, y] = gridObject;
                TriggerGridObjectChanged(x, y);
            }
        }

        //set value from world position
        public void SetGridObject(Vector3 worldPosition, TGridObject gridObject)
        {
            int x, y;
            GetXY(worldPosition, out x, out y);
            SetGridObject(x, y, gridObject);
        }

        //get value from x and y of the array
        public TGridObject GetGridObject(int x, int y)
        {
            if (x >= 0 && x < width && y >= 0 && y < height)
            {
                return gridArray[x, y];
            }
            else
            {
                return default(TGridObject);
            }
        }

        public TGridObject GetGridObject(Vector2Int pos)
        {
            return GetGridObject(pos.x, pos.y);
        }

        //get value from world position
        public TGridObject GetGridObject(Vector3 worldPosition)
        {
            int x, y;
            GetXY(worldPosition, out x, out y);
            return GetGridObject(x, y);

        }
        #endregion

        #region get grid object patterns
        List<TGridObject> returnObjList = new List<TGridObject>();

        public bool CheckWithinGrid(Vector2Int pos) {
            if (pos.x >= 0 && pos.x < width) {
                if (pos.y >= 0 && pos.y < height)
                    return true;
            }
            return false;
        }

        public bool CheckWithinGrid(Vector3 worldPosition)
        {
            if (worldPosition.x >= originPosition.x && worldPosition.x < originPosition.x + (cellSize*width))
            {
                if (worldPosition.y >= originPosition.y && worldPosition.y < originPosition.y + (cellSize * height))
                    return true;
            }
            return false;
        }

        public List<TGridObject> GetAdjacent(Vector2Int originPos, int range = 1, bool includeSelf = false)
        {
            returnObjList.Clear();
            List<Vector2Int> dirList = new List<Vector2Int>() { Vector2Int.up, Vector2Int.down, Vector2Int.left, Vector2Int.right };
            if (CheckWithinGrid(originPos) && includeSelf) returnObjList.Add(GetGridObject(originPos));
            foreach (var item in dirList)
            {
                if (CheckWithinGrid(originPos+(item*range))) returnObjList.Add(GetGridObject(originPos+ (item * range)));
            }
            return returnObjList;
        }

        public List<TGridObject> GetSurrounding(Vector2Int originPos,int range = 1, bool includeSelf = false)
        {
            returnObjList.Clear();
            List<Vector2Int> dirList = new List<Vector2Int>() { new Vector2Int(-1,1), new Vector2Int(1, 1), new Vector2Int(-1, -1), new Vector2Int(1, -1) };
            returnObjList.AddRange(GetAdjacent(originPos, range, includeSelf));
            foreach (var item in dirList)
            {
                if (CheckWithinGrid(originPos + (item * range))) returnObjList.Add(GetGridObject(originPos + (item * range)));
            }
            return returnObjList;
        }

        public List<TGridObject> GetArea(Vector2Int originPos, int range = 1, bool includeSelf = false)
        {
            returnObjList.Clear();
            Vector2Int temp;
            for (int x = originPos.x- range; x <= originPos.x+range; x++)
            {
                for (int y = originPos.y - range; y <= originPos.y + range; y++)
                {
                    temp = new Vector2Int(x, y);
                    if (CheckWithinGrid(temp)) {
                        if (temp == originPos && !includeSelf) continue;
                        returnObjList.Add(GetGridObject(temp));
                    }
                }
            }
            return returnObjList;
        }

        public List<TGridObject> GetRow(int y)
        {
            returnObjList.Clear();
            for (int x = 0; x < width; x++)
            {
                returnObjList.Add(gridArray[x, y]);
            }
            return returnObjList;
        }

        public List<TGridObject> GetColumn(int x)
        {
            returnObjList.Clear();
            for (int y = 0; y < height; y++)
            {
                returnObjList.Add(gridArray[x, y]);
            }
            return returnObjList;
        }

        #endregion

        #region entire grid manipulation
        public TGridObject[,] OutputArray()
        {
            return gridArray;
        }

        public void DoAllGridObjects(Action<int,int,TGridObject> function) {
            for (int x = 0; x < width; x++)
            {
                for (int y = 0; y < height; y++)
                {
                    function(x,y,gridArray[x, y]);
                }
            }
        }

        public void DestroyGrid()
        {
            if (!spawnText) return;
            for (int x = 0; x < width; x++)
            {
                for (int y = 0; y < height; y++)
                {


                    if (gridText[x, y] != null)
                    {
                        MonoBehaviour.Destroy(gridText[x, y].gameObject);

                    }


                }
            }
        }
        #endregion

        #region DebugText
        //trigger the update debug text event using gridArray Position
        public void TriggerGridObjectChanged(int x, int y)
        {
            if (OnGridObjectChanged != null && spawnText) OnGridObjectChanged(this, new OnGridObjectChangedArgs { x = x, y = y });
        }

        //trigger the update debug text event using world Position
        public void TriggerGridObjectChanged(Vector3 position)
        {
            int x, y;
            GetXY(position, out x, out y);
            if (OnGridObjectChanged != null && spawnText) OnGridObjectChanged(this, new OnGridObjectChangedArgs { x = x, y = y });
        }

        //configure debug text option
        //so far no use for this
        public void configureDebugText(bool show, Color textColour, int size)
        {

            this.showText = show;
            this.textColour = textColour;
            this.textSize = size;

            if (!spawnText) return;
            for (int x = 0; x < width; x++)
            {
                for (int y = 0; y < height; y++)
                {

                    //disable text if configured to not show
                    gridText[x, y]?.gameObject.SetActive(showText);
                    if (gridText[x, y] != null)
                    {
                        gridText[x, y].color = this.textColour;
                        gridText[x, y].fontSize = this.textSize;
                    }


                }
            }
        }

        //get if the text is shown
        public bool getShowText()
        {
            return showText;
        }

        // Create Text in the Grid
        private TextMeshPro CreateGridText(string text, Transform parent = null, int x = 0, int y = 0, Vector3 localPosition = default(Vector3), int fontSize = 40, Color? color = null, TextAlignmentOptions textAlignment = TextAlignmentOptions.Left, int sortingOrder = 5000)
        {
            if (color == null) color = Color.white;
            return CreateGridText(parent, text, $"Grid_Text_[{x}, {y}]", localPosition, fontSize, (Color)color, textAlignment, sortingOrder);
        }

        // Create Text in the Grid
        private TextMeshPro CreateGridText(Transform parent, string text, string objectName, Vector3 localPosition, int fontSize, Color color, TextAlignmentOptions textAlignment, int sortingOrder)
        {
            GameObject gameObject = new GameObject(objectName, typeof(TextMeshPro));
            Transform transform = gameObject.transform;
            transform.SetParent(parent, false);
            transform.localPosition = localPosition;
            TextMeshPro textMesh = gameObject.GetComponent<TextMeshPro>();
            textMesh.alignment = textAlignment;
            //textMesh.anchor = AnchorPositions.Center;
            textMesh.text = text;
            textMesh.fontSize = fontSize;
            textMesh.color = color;
            textMesh.GetComponent<MeshRenderer>().sortingOrder = sortingOrder;
            return textMesh;
        }
        #endregion
    }

}