// See https://aka.ms/new-console-template for more information
using AdventCommon;

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

Console.WriteLine("Part01 Example Sum: " + p1exampleSln);
Console.WriteLine("Part01 Puzzle Sum: " + p1puzzleSln);

/** P2 **/
var p2exampleSln = Part02(new AdventCommon.PuzzleInput("example-input-2.txt"));
var p2puzzleSln = Part02(new AdventCommon.PuzzleInput("puzzle-input.txt"));

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

int Part01(PuzzleInput input)
{
    int sum = 0;

    foreach (var line in input.Lines)
    {
        int num = 0;

        // Left digit
        for (int i = 0;  i < line.Length; i++)
        {
            if (Char.IsDigit(line[i]))
            {
                num += 10 * (line[i] - '0');
                break;
            }
        }

        // Right digit
        for (int i = line.Length-1; i >= 0; i--)
        {
            if (Char.IsDigit(line[i]))
            {
                num += line[i] - '0';
                break;
            }
        }

        sum += num;
    }

    return sum;
}

int Part02(PuzzleInput input)
{
    int sum = 0;

    foreach (var line in input.Lines)
    {
        int num = 0;

        // Left digit
        for (int i = 0; i < line.Length; i++)
        {
            var val = ReadInteger(line, i);

            if (val != -1)
            {
                num += 10 * val;
                break;
            }
        }

        // Right digit
        for (int i = line.Length - 1; i >= 0; i--)
        {
            var val = ReadInteger(line, i);

            if (val != -1)
            {
                num += val;
                break;
            }
        }

        sum += num;
    }

    return sum;
}

int ReadInteger(string line, int index)
{
    // If its a digit, we done
    if (Char.IsDigit(line[index]))
    {
        return line[index] - '0';
    }
    else
    {
        // Ok read string
        int number_index = 1;
        var number = new string[] { "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };

        foreach (var num in number)
        {
            if (index + num.Length <= line.Length)
            {
                bool found = true;

                for (int i = 0; i < num.Length && (index + i) < line.Length; i++)
                {
                    if (num[i] != line[index + i])
                    {
                        found = false;
                        break;
                    }
                }

                if (found)
                {
                    return number_index;
                }
            }

            number_index++;
        }
    }

    return -1;
}