async Task Main()
{
	await RunAsync(File.ReadAllText(@"C:\Users\guy\source\repos\AoCMAUI\AoCService\Inputs\2024Day12.txt"), new Parts()).Dump();

	async Task<(string Part1, string Part2)> RunAsync(string input, Parts parts)
	{
		(string Part1, string Part2) result = ("", "");
		if (parts.One) result.Part1 = FencePlotter(input, false);
		if (parts.Two) result.Part2 = FencePlotter(input, true);
		return result;
	}

	string FencePlotter(string input, bool part2)
	{
		var lines = input.SplitLines();
		var xMax = lines[0].Length - 1;
		var yMax = lines.Count() - 1;
		char[,] map = new char[xMax + 1, yMax + 1];
		for(var i = 0; i < lines.Count(); i++)
		{
			for(var j = 0; j < lines[i].Length; j++)
			{
				map[i,j] = lines[i][j];
			}
		}
		var visited = new List<string>();
		var q = new Queue<(int i,int j, Direction d)>();
		var regions = new List<(char ch, int area, int perimeter)>();
		var regions2 = new List<(char ch, List<(int i, int j)>, int area)>();
		for(var i = 0; i < lines.Count(); i++)
		{
			for(var j = 0; j < lines[i].Length; j++)
			{
				if (visited.Contains($"{i}|{j}")) continue;
				var area = 0;
				var perimeter = 0;
				var cells = new List<(int, int)>();
				visited.Add($"{i}|{j}");
				cells.Add((i, j));
				var neighbours = MatchingNeighbours(i, j, map[i, j], map);
				foreach(var n in neighbours) q.Enqueue(n);
				area++;
				perimeter += 4 - neighbours.Count();
				while(q.Any())
				{
					(int i, int j, Direction d) item = q.Dequeue();
					if (visited.Contains($"{item.Item1}|{item.Item2}")) continue;
					visited.Add($"{item.Item1}|{item.Item2}");
					cells.Add((item.i, item.j));
					var ne = MatchingNeighbours(item.Item1, item.Item2, map[item.Item1, item.Item2], map);
					foreach(var n in ne) q.Enqueue(n);
					area++;
					perimeter += 4 - ne.Count();
				}
				regions.Add((map[i,j], area, perimeter));
				regions2.Add((map[i,j], cells, area));
			}
		}
		//map.Dump();
		//regions.Dump();
		//regions2.Dump();
		var totalFence = regions.Sum(r => r.perimeter * r.area);
		if(!part2) return $"{totalFence}";
		var discountFence = 0;
		foreach(var r2 in regions2)
		{
			var count = FindSides(r2);
			discountFence += count * r2.area;
			//$"{r2.ch}, {r2.area}, {count}".Dump();
		}
		return $"{discountFence}";
	}


}

int FindSides((char ch, List<(int i, int j)> cells, int area) r2)
{
	var edges = r2.cells.Count * 4;
	foreach(var cell in r2.cells)
	{
		var below = CellBelow(r2.cells, cell);
		var left = CellLeft(r2.cells, cell);
		var right = CellRight(r2.cells, cell);
		var above = CellAbove(r2.cells,cell);
		if(right)
		{
			edges--;
			if(!below && !CellBelow(r2.cells, (cell.i + 1, cell.j))) edges--;
			if(!above && !CellAbove(r2.cells, (cell.i + 1, cell.j))) edges--;
		}
		if(below)
		{
			edges--;
			if(!left && !CellLeft(r2.cells, (cell.i, cell.j + 1))) edges--;
			if(!right && !CellRight(r2.cells, (cell.i, cell.j + 1))) edges--;
		}
		if(left) edges--;
		if(above) edges--;
	}

	return edges;
}

bool CellBelow(List<(int i, int j)> cells, (int i, int j) cell)
{
	return cells.Any(c => c.i == cell.i && c.j == cell.j + 1);
}
bool CellAbove(List<(int i, int j)> cells, (int i, int j) cell)
{
	return cells.Any(c => c.i == cell.i && c.j == cell.j - 1);
}
bool CellLeft(List<(int i, int j)> cells, (int i, int j) cell)
{
	return cells.Any(c => c.i == cell.i - 1 && c.j == cell.j);
}
bool CellRight(List<(int i, int j)> cells, (int i, int j) cell)
{
	return cells.Any(c => c.i == cell.i + 1 && c.j == cell.j);
}


static List<(int i, int j, Direction d)> MatchingNeighbours(int i, int j, char ch, char[,] map)
{
	var neighbours = new List<(int i, int j, Direction d)>();
	if (i > 0 && map[i - 1, j] == ch) neighbours.Add((i - 1, j, Direction.L));
	if (j > 0 && map[i, j - 1] == ch) neighbours.Add((i, j - 1, Direction.U));
	if (i < map.GetUpperBound(0) && map[i + 1, j] == ch) neighbours.Add((i + 1, j, Direction.R));
	if (j < map.GetUpperBound(1) && map[i, j + 1] == ch) neighbours.Add((i, j + 1, Direction.D));
	return neighbours;
}

enum Direction
{
	U,
	R,
	D,
	L
}