ISUCK

public class Day12
{
    private char[,] input;
    private int cols;
    private int rows;
    private HashSet<(int x, int y)> workedCells;
    private List<(int x, int y)> directions = [(0, -1), (1, 0), (0, 1), (-1, 0)];
    public Day12()
    {
        Console.WriteLine("Day12");
        input = GetInput(false);
        cols = input.GetLength(0);
        rows = input.GetLength(1);
        Day12P1();
        Day12P2();
    }

    private void Day12P1()
    {
        workedCells = [];
        int fenceCost = 0;
        for (int y = 0; y < rows; y++)
        {
            for (int x = 0; x < cols; x++)
            {
                if (!workedCells.Contains((x, y)))
                {
                    fenceCost += BeginNewSection(x, y, input[x, y]);
                }
            }
        }
        Console.WriteLine(fenceCost);
    }

    private void Day12P2()
    {
        workedCells = [];
        int fenceCost = 0;
        for (int y = 0; y < rows; y++)
        {
            for (int x = 0; x < cols; x++)
            {
                if (!workedCells.Contains((x, y)))
                {
                    fenceCost += BeginNewSection(x, y, input[x, y], true);
                }
            }
        }
        Console.WriteLine(fenceCost);
    }

    private int BeginNewSection(int x, int y, char type, bool useCorners = false)
    {
        var plantPlot = WorkCell(x, y, type);
        //Console.WriteLine($"{type} has {plantPlot.edges} fences and {plantPlot.cells} cells and {plantPlot.corners} corners");
        if (useCorners) return plantPlot.corners * plantPlot.cells;
        return plantPlot.edges * plantPlot.cells;
    }

    private (int edges, int cells, int corners) WorkCell(int x, int y, char type)
    {
        if (workedCells.Contains((x, y)) || x < 0 || x >= cols || y < 0 || y >= rows) return (0, 0, 0);
        workedCells.Add((x, y));
        int edges = 0;
        int cells = 1;
        int corners = 0;
        for (int i = 0; i < directions.Count; i++)
        {
            var dir = directions[i];
            (int x, int y) cellToCheck = (x + dir.x, y + dir.y);
            bool cellIsOutOfBounds = false;
            if (cellToCheck.x < 0 || cellToCheck.x >= cols || cellToCheck.y < 0 || cellToCheck.y >= rows) cellIsOutOfBounds = true;
            if (cellIsOutOfBounds || input[cellToCheck.x, cellToCheck.y] != type) edges++;
            if (!cellIsOutOfBounds && !workedCells.Contains(cellToCheck) && input[cellToCheck.x, cellToCheck.y] == type)
            {
                var workedCell = WorkCell(cellToCheck.x, cellToCheck.y, type);
                edges += workedCell.edges;
                cells += workedCell.cells;
                corners += workedCell.corners;
            }
            if (cellIsOutOfBounds || input[cellToCheck.x, cellToCheck.y] != type)
            {
                (int x, int y) cornerIndexToCheck = (directions[(i + 1) % 4].x + x, directions[(i + 1) % 4].y + y);
                bool nextCellIsOutOfBounds = false;
                if (cornerIndexToCheck.x < 0 || cornerIndexToCheck.x >= cols || cornerIndexToCheck.y < 0 || cornerIndexToCheck.y >= rows) nextCellIsOutOfBounds = true;
                if (nextCellIsOutOfBounds || input[cornerIndexToCheck.x, cornerIndexToCheck.y] != type) corners++;
                else
                {
                    (int x, int y) innerCornerCheck = (directions[(i + 1) % 4].x + cellToCheck.x, directions[(i + 1) % 4].y + cellToCheck.y);
                    bool innerCornerCheckIsOutOfBounds = false;
                    if (innerCornerCheck.x < 0 || innerCornerCheck.x >= cols || innerCornerCheck.y < 0 || innerCornerCheck.y >= rows) innerCornerCheckIsOutOfBounds = true;
                    if (!innerCornerCheckIsOutOfBounds && input[innerCornerCheck.x, innerCornerCheck.y] == type) corners++;
                }
            }
        }
        return (edges, cells, corners);
    }

    private char[,] GetInput(bool test)
    {
        string inputRaw;
        if (test)
        {
            inputRaw =
"""
RRRRIICCFF
RRRRIICCCF
VVRRRCCFFF
VVRCCCJFFF
VVVVCJJCFE
VVIVCCJJEE
VVIIICJJEE
MIIIIIJJEE
MIIISIJEEE
MMMISSJEEE
"""; //p1 1930 p2 1206
     //             inputRaw =
     // """
     // AAAAAA
     // AAABBA
     // AAABBA
     // ABBAAA
     // ABBAAA
     // AAAAAA
     // """; //p2 368
        }
        else
        {
            inputRaw = File.ReadAllText(@"Data\Day12.txt");
        }
        var c = inputRaw.Split("\n")[0].Trim().Length;
        var r = inputRaw.Split('\n').Length;
        char[,] input = new char[c, r];
        for (int y = 0; y < r; y++)
        {
            var row = inputRaw.Split("\n")[y].Trim();
            for (int x = 0; x < c; x++)
            {
                input[x, y] = row[x];
            }
        }
        return input;
    }
}