// See https://aka.ms/new-console-template for more information
using AdventCommon;
using System.Security.AccessControl;
using System.Security.Cryptography.X509Certificates;

/** P1 **/
var p1exampleSln = Part01(new Day01Parsed("example-input.txt"));
var p1puzzleSln = Part01(new Day01Parsed("puzzle-input.txt"));

Console.WriteLine("Part01 Total Distance: " + p1exampleSln);
Console.WriteLine("Part01 Total Distance: " + p1puzzleSln);

/** P2 **/
var p2exampleSln = Part02(new Day01Parsed("example-input.txt"));
var p2puzzleSln = Part02(new Day01Parsed("puzzle-input.txt"));

Console.WriteLine("Part02 Example Sum: " + p2exampleSln);
Console.WriteLine("Part02 Puzzle Sum: " + p2puzzleSln);

int GetDistance(int l, int r)
{
    return Math.Abs(l - r);
}

int Part01(Day01Parsed input)
{
    int distance = 0;
    input.left.Sort();
    input.right.Sort();

    for (int i = 0; i < input.left.Count; i++)
    {
        distance += GetDistance(input.left[i], input.right[i]);
    }

    return distance;
}

int Part02(Day01Parsed input)
{
    int total = 0;

    for (int i = 0; i < input.left.Count; i++)
    {
        var l = input.left[i];
        total += l * input.GetSimilarity(l);
    }

    return total;
}

class Day01Parsed : AdventCommon.ParsedInput
{
    public List<int> left = new List<int>();
    public List<int> right = new List<int>();

    public int GetSimilarity(int value)
    {
        int instances = 0;

        foreach (var item in right)
        {
            if (item == value)
            {
                instances++;
            }
        }

        return instances;
    }

    public Day01Parsed(string fileName) : base(fileName) 
    {
        if (left.Count != right.Count)
        {
            throw new Exception("Improperly formatted input file");
        }
    }

    public override bool ParseLine(string line, object? context = null)
    {
        var split = line.Split(' ', StringSplitOptions.RemoveEmptyEntries);

        if (split.Length != 2)
        {
            return false;
        }

        var l = Int32.Parse(split[0]);
        var r = Int32.Parse(split[1]);

        left.Add(l);
        right.Add(r);

        return true;
    }
}