public class Day2
{
    public void Go()
    {
        //var input = File.ReadAllText("Day2/ExampleData.txt");
        var input = File.ReadAllText("Day2/RealData.txt");
        var inputs = input.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
        var pairs = inputs.Select(s =>
            s.Split('-', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries))
            .Select(s => new Tuple<Int64,Int64>(Int64.Parse(s[0]), Int64.Parse(s[1])));

        Int64 sum = 0;
        foreach (var pair in pairs)
        {
            sum += CheckPair2(pair);
        }

        Console.WriteLine($"Total invalid sum: {sum}");
    }

    public Int64 CheckPair(Tuple<Int64, Int64> pair)
    {
        Int64 sum = 0;
        
        for (Int64 i = pair.Item1; i <= pair.Item2; i++)
        {
            var s =  i.ToString();
            if (s.Length%2 == 1)
            {
                continue;
            }
            
            var p1 = s.Substring(0, s.Length/2);
            var p2 = s.Substring(s.Length/2);

            if (p1 == p2)
            {
                Console.WriteLine($"INVALID PAIR: {s} is made up of {p1} and {p2}");
                sum += i;
            }
        }

        return sum;
    }
    
    public Int64 CheckPair2(Tuple<Int64, Int64> pair)
    {
        Int64 sum = 0;
        
        for (Int64 id = pair.Item1; id <= pair.Item2; id++)
        {
            var s =  id.ToString();
            
            for (int searchLength = 1; searchLength <= s.Length/2; searchLength++)
            {
                if (s.Length%searchLength != 0)
                {
                    continue;
                }

                var valid = true;
                var firstSet = s.Substring(0, searchLength);
                
                for (int repeatPosition = 1; repeatPosition < s.Length/searchLength; repeatPosition++)
                {
                    var checkSet = s.Substring(searchLength*repeatPosition, searchLength);

                    if (firstSet != checkSet)
                    {
                        valid = false;
                        break;
                    }
                }
                
                if (valid)
                {
                    Console.WriteLine($"INVALID ID: {s} is made up of {firstSet} {s.Length/searchLength} times");
                    sum += id;
                    break;
                }
                
            }
        }

        return sum;
    }
}