using System.Collections.Frozen;
using System.Numerics;
using Spectre.Console;

namespace AdventOfCode.Days;

public class Day11 : Day
{
    public override int Number => 11;
    public override string Name => "Plutonian Pebbles";

    private const int BlinkIterations = 25;

    public override void RunPart1(bool display = true)
    {
        var stones = ParseStones();

        for (var iteration = 0; iteration < BlinkIterations; iteration++)
        {
            var index = 0;

            while (index < stones.Count)
            {
                var stone = stones[index];
                var stoneString = stone.ToString();

                if (stone is 0)
                {
                    stones[index] = 1;
                }
                else if (stoneString.Length % 2 == 0)
                {
                    var splitIndex = stoneString.Length / 2;

                    var leftStone = long.Parse(stoneString[..splitIndex]);
                    var rightStone = long.Parse(stoneString[splitIndex..]);

                    stones[index] = leftStone;
                    stones.Insert(index + 1, rightStone);

                    index++;
                }
                else
                {
                    stones[index] = stone * 2024;
                }

                index++;
            }
        }

        if (display)
        {
            AnsiConsole.MarkupLine($"[green]Number of stones after blinking {BlinkIterations} times: [yellow]{stones.Count}[/][/]");
        }
    }

    public override void RunPart2(bool display = true)
    {
        var stones = ParseStones().ToDictionary(s => s, _ => 1L);

        for (var iteration = 0; iteration < (BlinkIterations * 3); iteration++)
        {
            var stonesToIterate = stones.ToList();

            foreach (var (stone, count) in stonesToIterate)
            {
                var stoneString = stone.ToString();

                if (stone is 0)
                {
                    SafeAdd(stones, 1, count);
                }
                else if (stoneString.Length % 2 == 0)
                {
                    var splitIndex = stoneString.Length / 2;

                    var leftStone = long.Parse(stoneString[..splitIndex]);
                    var rightStone = long.Parse(stoneString[splitIndex..]);

                    SafeAdd(stones, leftStone, count);
                    SafeAdd(stones, rightStone, count);
                }
                else
                {
                    SafeAdd(stones, stone * 2024, count);

                }

                SafeAdd(stones, stone, -count);
            }
        }

        var stonesCount = stones.Sum(p => p.Value);

        if (display)
        {
            AnsiConsole.MarkupLine($"[green]Number of stones after blinking {BlinkIterations} times: [yellow]{stonesCount}[/][/]");
        }
    }

    private List<long> ParseStones()
    {
        var stones = new List<long>();

        var span = Input.AsSpan();

        foreach (var stoneRange in span.Split(' '))
        {
            stones.Add(long.Parse(span[stoneRange]));
        }

        return stones;
    }

    private void SafeAdd(Dictionary<long, long> dictionary, long key, long valueToAdd)
    {
        if (dictionary.TryGetValue(key, out var currentValue))
        {
            dictionary[key] = currentValue + valueToAdd;
        }
        else
        {
            dictionary[key] = valueToAdd;
        }
    }
}