using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using CDSAE3_Lian_Lian_Kan;
namespace CDSAE3_Lian_Lian_Kan.Board_funcs
{
    public partial class Board
    {
        public Board() {
        }
        public int[,]? Bd { get; set; } = null;//y,x
        public int[]? vals_per_Image = null;
        public int total;
        public int Total { get
            {
                return total;
            } 
            set
            {
                total = value;
                if(total == 0)
                    Settings.game_mode_form?.Finished_Handler(this, new Forms.FinishArgs { finish_Type = Forms.FinishArgs.Finish_Type.All_done });
            } }
        public void make_board()
        {
            var rand = new Random();
            size = Settings.get_length_width();
            var (width, height) = size;
            Bd = new int[height + 2, width + 2];
            for (int i = 0; i < height + 2; i++)
                for (int j = 0; j < width + 2; j++)
                    Bd[i, j] = -1;
            int sum = width * height;
            if (sum % 2 != 0)
                sum--;
            total = sum;
            int types = Settings.Images_size();
            vals_per_Image = new int[types];
            int single = sum/types;
            for(int k = sum; k>0; k-=2)
            {
                int t = rand.Next(0, types);
                if (vals_per_Image[t] >= 1.5*single)
                {
                    k += 2;
                    continue;
                }
                vals_per_Image[t]+=2;
            }
            int cur_width = 1, cur_height = 1;
            var temp_val_per_Image = (int[])vals_per_Image.Clone();
            Func<int> getval = () =>
            {
                int t = rand.Next(0, types);
                if (temp_val_per_Image[t] == 0)
                {
                    int i = (t + 1)%types;
                    for (; temp_val_per_Image[i] == 0; i %= types)
                        i++;
                    temp_val_per_Image[i]--;
                    return i;
                }
                temp_val_per_Image[t]--;
                return t;
            };
            for (int i=0;i<sum;i++)
            {
                Bd[cur_height,cur_width] = getval();
                cur_width++;
                if (cur_width > width)
                { 
                    cur_height++;
                    cur_width = 1;
                }
            }
            return;
        }
        public (bool,List<(int,int)>?) test((int,int) a,(int,int) b)//x,y
        {
            bool reverse = false;
            if (a == b)
                return (false,null);
            if (Bd?[a.Item2, a.Item1] != Bd?[b.Item2, b.Item1])
                return (false,null);
            var (xa, ya) = a;
            var (xb, yb) = b;
            Func<bool, int, int, int,bool> line_test = (bool x,int ct,int from,int to) =>
            {//ct is x (x==true)left to right ///up to down
                if (from > to)
                    (from, to) = (to, from);
                if (x)
                {
                    for (int i = from + 1; i < to; i++)
                        if (Bd?[ct, i] != -1)
                            return false;
                }
                else
                    for (int i = from + 1; i < to; i++)
                        if (Bd?[i, ct] != -1)
                            return false;
                return true;
            };
            if (xa == xb)
                if (line_test(false, xa, ya, yb))
                    return (true, new List<(int, int)> { a, b });
            if (ya == yb)
                if (line_test(true, ya, xa, xb))
                    return (true, new List<(int, int)> { a, b });
            (int, int)[] squareA = new (int, int)[4];
            (int, int)[] squareB = new (int, int)[4];//urdl
            {//two line test
                HashSet<(int, int)> reachableA = new HashSet<(int, int)>(), reachableB = new HashSet<(int, int)>();
                Func<(int, int), HashSet<(int, int)>, bool> check_insert = ((int, int) pos, HashSet<(int, int)> insert) =>//x,y
                {
                    if (pos.Item1 < 0 || pos.Item2 < 0 || pos.Item1 >= Bd?.GetLength(1) || pos.Item2 >= Bd?.GetLength(0))
                        return false;
                    if (Bd?[pos.Item2, pos.Item1] == -1)
                    {
                        insert.Add(pos);
                        return true;
                    }
                    return false;
                };
                Func<(int, int), HashSet<(int, int)>, HashSet<(int, int)>, (int, int)[], (bool, int, int)> cross_test = ((int, int) pos, HashSet<(int, int)> insert, HashSet<(int, int)> test, (int, int)[] square) =>//x,y
                {

                    var (x, y) = pos;
                    for (x--; ; x--)
                        if (check_insert((x, y), insert))
                        {
                            if (test.Contains((x, y)))
                                return (true, x, y);
                        }
                        else
                        {
                            square[3] = (x + 1, y);
                            break;
                        }
                    (x, y) = pos;
                    for (x++; ; x++)
                        if (check_insert((x, y), insert))
                        {
                            if (test.Contains((x, y)))
                                return (true, x, y);
                        }
                        else
                        {
                            square[1] = (x - 1, y);
                            break;
                        }
                    (x, y) = pos;
                    for (y--; ; y--)
                        if (check_insert((x, y), insert))
                        {
                            if (test.Contains((x, y)))
                                return (true, x, y);
                        }
                        else
                        {
                            square[0] = (x, y + 1);
                            break;
                        }
                    (x, y) = pos;
                    for (y++; ; y++)
                        if (check_insert((x, y), insert))
                        {
                            if (test.Contains((x, y)))
                                return (true, x, y);
                        }
                        else
                        {
                            square[2] = (x, y - 1);
                            break;
                        }
                    return (false, -1, -1);
                };
                cross_test(a, reachableA, reachableB, squareA);
                var (find_ans, pax, pay) = cross_test(b, reachableB, reachableA, squareB);
                if (find_ans)
                    return (true, new List<(int, int)> { a, (pax, pay), b });
                if (reachableA.Count > reachableB.Count)
                { 
                    (a, b) = (b, a);
                    reverse = true;
                }
            }
            {//three line test
                Func<(int, int), (int, int), (bool, (int, int))> intersection = ((int, int) a, (int, int) b) =>
                {
                    if (a.Item1 > b.Item1)
                        (a, b) = (b, a);
                    if (a.Item2 < b.Item1)
                        return (false, (-1, -1));
                    if (a.Item2 > b.Item2)
                        return (true,( b.Item1, b.Item2));
                    return (true, (b.Item1, a.Item2));
                };
                var (throughx, xrange) = intersection((squareA[3].Item1, squareA[1].Item1), (squareB[3].Item1, squareB[1].Item1));
                var (throughy, yrange) = intersection((squareA[0].Item2, squareA[2].Item2), (squareB[0].Item2, squareB[2].Item2));
                if (throughx)
                    for (int i = xrange.Item1; i <= xrange.Item2; i++)
                        if (line_test(false, i, a.Item2, b.Item2))
                            if (reverse)
                                return (true, new List<(int, int)> { b, (i, b.Item2), (i, a.Item2), a });
                            else
                                return (true, new List<(int, int)> { a, (i, a.Item2), (i, b.Item2), b });
                if (throughy)
                    for (int i = yrange.Item1; i <= yrange.Item2; i++)
                        if (line_test(true, i, a.Item1, b.Item1))
                            if (reverse)
                                return (true, new List<(int, int)> { b, (b.Item1, i), (a.Item1, i), a });
                            else
                                return (true, new List<(int, int)> { a, (a.Item1, i), (b.Item1, i), b });
            }
            return (false, null);
        }
        public (int, int) size { get; set; }//width,height
        public Settings.Mode mode { get; set; }
    }
}