var lines = File.ReadAllLines("input.txt");
var charArray = new char[lines.Length, lines[0].Length];
Dictionary<Direction, (int dx, int dy)> moves = new()
{
    { Direction.Up, (-1, 0) },
    { Direction.Right, (0, 1) },
    { Direction.Down, (1, 0) },
    { Direction.Left, (0, -1) }
};

var guardCurrentPosition = (0, 0);
var guardDirection = Direction.Up;
var visitedPositions = new List<int[]>();

for (var i = 0; i < charArray.GetLength(0); i++)
for (var j = 0; j < charArray.GetLength(1); j++)
{
    if (lines[i][j] == '^')
    {
        guardCurrentPosition.Item1 = i;
        guardCurrentPosition.Item2 = j;
        visitedPositions.Add([guardCurrentPosition.Item1, guardCurrentPosition.Item2]);
    }

    charArray[i, j] = lines[i][j];
}

var nextPosition = CalculateNextPosition(guardCurrentPosition.Item1, guardCurrentPosition.Item2, guardDirection);

while (IsValid(nextPosition.Item1, nextPosition.Item2, charArray))
{
    if (IsBlocked(nextPosition.Item1, nextPosition.Item2, charArray))
    {
        guardDirection = (Direction)(((int)guardDirection + 1) % 4);
    }
    else
    {
        guardCurrentPosition = (nextPosition.Item1, nextPosition.Item2);
        visitedPositions.Add([guardCurrentPosition.Item1, guardCurrentPosition.Item2]);
    }

    nextPosition = CalculateNextPosition(guardCurrentPosition.Item1, guardCurrentPosition.Item2, guardDirection);
}

Console.WriteLine($"Part1: {visitedPositions.Select(x => $"r{x[0]},c{x[1]}").Distinct().Count()}");
PrintMap(charArray, visitedPositions);

(int, int) CalculateNextPosition(int row, int col, Direction direction)
{
    var (dx, dy) = moves[direction];
    return (row + dx, col + dy);
}

bool IsValid(int row, int column, char[,] grid) => row >= 0 && row < grid.GetLength(0) && column >= 0 && column < grid.GetLength(1);

bool IsBlocked(int row, int col, char[,] grid) => grid[row, col] == '#';

void PrintMap(char[,] input, List<int[]> visitedPositions)
{
    for (var i = 0; i < input.GetLength(0); i++)
    {
        for (var j = 0; j < input.GetLength(1); j++)
        {
            if (visitedPositions.Any(x => x[0] == i && x[1] == j) && input[i, j] != '^')
            {
                Console.Write("X");
            }
            else
            {
                Console.Write(input[i, j]);
            }
        }

        Console.WriteLine();
    }
}

enum Direction
{
    Up,
    Right,
    Down,
    Left
}