package Advent2018;

import util.AdventOfCode;

import java.util.List;

public class Day14 extends AdventOfCode {

    int intInput;

    public Day14(List<String> input) {
        super(input);
        title = "Chocolate Charts";
        part1Description = "Scores of ten recipes after goal: ";
        part2Description = "Number of recipes to get to input sequence: ";
    }

    StringBuilder makeRecipes(int goal) {
        StringBuilder scores = new StringBuilder();
        int a = 3;
        int b = 7;
        int aPos = 0;
        int bPos = 1;
        scores.append(String.valueOf(a));
        scores.append(String.valueOf(b));
        while (scores.length() < goal + 10) {
            int sum = a + b;
            if (sum > 9) {
                scores.append(String.valueOf(sum / 10));
                scores.append(String.valueOf(sum % 10));
            } else {
                scores.append(String.valueOf(sum));
            }
            aPos = (aPos + (1 + a)) % scores.length();
            bPos = (bPos + (1 + b)) % scores.length();
            a = scores.charAt(aPos) - '0';
            b = scores.charAt(bPos) - '0';
        }
        return scores;
    }

    @Override
    public Object part1() {
        return makeRecipes(intInput).substring(intInput);
    }

    @Override
    public Object part2() {
        return makeRecipes(30_000_000).indexOf(input.get(0));
    }

    @Override
    public void parse() {
        intInput = Integer.parseInt(input.get(0));
    }

}