using Chess;
using System;
using System.Windows;
using System.Collections;

namespace ChessPanel
{
    public class Grid : IEnumerable
    {
        public Grid(int GridSize)
        {
            fields = new Field[GridSize, GridSize];
            this.GridSize = GridSize;
        }
        //public Grid(Field[,] fields)
        //{
        //    this.GridSize = fields.GetLength(0);
        //    this.fields = CopyMultiArray(fields);
        //}
        /// <summary>
        /// Creates a copy of the given array;
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="Array"></param>
        /// <returns></returns>
        private static T[,] CopyMultiArray<T>(T[,] Array)
        {
            int[] dim = new int[] { Array.GetLength(0), Array.GetLength(1) };
            T[,] Copy = new T[dim[0], dim[1]];
            for (int x = 0; x < dim[0]; x++)
                for (int y = 0; y < dim[1]; y++)
                    Copy[x, y] = Array[x, y];
            return Copy;
        }
        //public Grid(Grid fields) : this(fields.fields) { }
        public Field[,] fields;
        public int GridSize;
        public Field this[Vector v] { get { return fields[(int)v.X, (int)v.Y]; } set { fields[(int)v.X, (int)v.Y] = value; } }

        internal Piece GetKing(PieceColor color)
        {
            foreach (Field item in this)
            {
                if (item.CurrentPiece?.color == color && item.CurrentPiece?.type == PieceType.King)
                    return item.CurrentPiece;
            }
            throw new Exception("No King found");
        }

        public Field this[int x, int y] { get { return fields[x, y]; } set { fields[x, y] = value; } }
        public Field this[double x, double y] { get { return fields[(int)x, (int)y]; } set { fields[(int)x, (int)y] = value; } }
        /// <summary>
        /// Adds x and y values to Vector v and gets the field at the position
        /// </summary>
        /// <param name="v">Vector</param>
        /// <param name="x">X</param>
        /// <param name="y">Y</param>
        /// <returns>Field</returns>
        public Field this[Vector v, int x, int y] { get { return fields[x + (int)v.X, y + (int)v.Y]; } set { fields[x + (int)v.X, y + (int)v.Y] = value; } }
        public Field this[int x, int y, Vector v] { get { return fields[x + (int)v.X, y + (int)v.Y]; } set { fields[x + (int)v.X, y + (int)v.Y] = value; } }
        public Field this[Vector v, double x, double y]
        {
            get
            {
                return fields[(int)x + (int)v.X, (int)y + (int)v.Y];
            }
            set
            {
                fields[(int)x + (int)v.X, (int)y + (int)v.Y] = value;
            }
        }
        public Field this[double x, double y, Vector v] { get { return fields[(int)x + (int)v.X, (int)y + (int)v.Y]; } set { fields[(int)x + (int)v.X, (int)y + (int)v.Y] = value; } }
        public Field GetFieldWithOffset(Field f, double x, double y)
        {
            int _x = (int)(f.location.X + x);
            int _y = (int)(f.location.Y + y);
            return fields[_x, _y];
        }



        /// <summary>
        /// Checks if a field is endagered by a party
        /// </summary>
        /// <param name="field">Reference to the Field that should be checked</param>
        /// <param name="color">Color of the attacking party</param>
        /// <param name="movePiece">Piece that virtually got moved</param>
        /// <param name="targetPos">Field that the movePiece virtually moved to</param>
        /// <returns></returns>
        public bool IsFieldVirtuallyEndagered(Field field, PieceColor color, Piece movePiece, Field targetPos)
        {
            foreach (Field item in this)
            {
                if (item.IsEmpty) continue; // Feld ist leer
                if (item == movePiece.field) continue; // Quellfeld muss nicht geprüft werden

                Piece p = item.CurrentPiece;
                if (p.color != color) continue; // Figur ist kein Gegner

                // Ask every Piece of the other party if it can attack the specified field
                if (p.EndageresFieldWithVirtualMove(this, field, movePiece, targetPos))
                    //if (item.currentPiece.GetValidTargetFields(movePiece, targetPos).ContainsKey(field))
                    return true;
            }
            return false;

        }



        IEnumerator IEnumerable.GetEnumerator()
        {
            return new FieldEnum(fields);
        }
    }

    // When you implement IEnumerable, you must also implement IEnumerator.
    public class FieldEnum : IEnumerator
    {
        public Field[,] field;

        // Enumerators are positioned before the first element
        // until the first MoveNext() call.
        int position = -1;
        int width;
        int height;

        public FieldEnum(Field[,] list)
        {
            field = list;
            width = list.GetLength(0);
            height = list.GetLength(1);
        }

        public bool MoveNext()
        {
            position++;
            return (position < field.Length);
        }

        public void Reset()
        {
            position = -1;
        }

        object IEnumerator.Current
        {
            get
            {
                return Current;
            }
        }

        public Field Current
        {
            get
            {
                try
                {
                    return field[position % 8, position / 8];
                }
                catch (IndexOutOfRangeException)
                {
                    throw new InvalidOperationException();
                }
            }
        }
    }
}