namespace adventOfCode.day12;


record Pin(int X, int Y);

class Block
{
    private HashSet<Pin> Pins;

    public Block(HashSet<Pin> pins)
    {
        Pins = pins;
    }
    
    public static Block CreateBlock(string blockSection)
    {
        blockSection = blockSection.Replace("\n", "");
        var pins = new HashSet<Pin>(9);
        for (var i = 0; i < 3; i++)
        {
            for (var j = 0; j < 3; j++)
            {
                if (blockSection[3 *i +  j] == '#')
                {
                    pins.Add(new Pin(i, j));
                }
            }
        }

        return new Block(pins);
    }

    public override string ToString()
    {
        var ret = "";
        for (var i = 0; i < 3; i++)
        {
            for (var j = 0; j < 3; j++)
            {
                ret += Pins.Contains(new Pin(i, j)) ? "#" : ".";

            }

            ret += "\n";
        }
        return ret;
    }

    public Block Flip()
    {
        return new Block((from pin in Pins select new Pin(pin.Y, pin.X)).ToHashSet());
    }
};

public class Day12
{
    private static string GetBlockSections(string document)
    {
        var xIndex = document.IndexOf("x");

        var index = -1;
        while (true)
        {
            var newIndex = document.IndexOf("\n", index + 1);
            if (newIndex > xIndex)
            {
                return document.Substring(0, index -1);
            }

            index = newIndex;
        }
    }

    static string ToBlockString(string blockSection)
    {
        return blockSection.Substring(blockSection.IndexOf("\n"));

    }

    static List<Block> ParseBlocks(string document)
    {
        var blockSections = GetBlockSections(document).Split("\n\n");
        return (from blockSection in blockSections select Block.CreateBlock(ToBlockString(blockSection))).ToList();
    }

    

    public static void Main(string[] args)
    {
        var b = Block.CreateBlock("###\n##.\n##.");
        Console.WriteLine(b);
        Console.WriteLine("\n\n\n");
        Console.WriteLine(b.Flip());
        
        Console.WriteLine("\n\n\n");
        Console.WriteLine(b.Flip().Flip());
        
    }
}