Day12.java

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Stream;

import com.google.gson.Gson;

public class Day12 {
	static final Pattern DIGITS = Pattern.compile("[\\[\\{\\]\\}:\\\"a-zA-Z,\\s]"); // original ("-?\\d+");
	static final String FILENAME = "D:\\_JavaProjects\\AdventOfCodeDay12\\InputDay12.txt";
	
	public static void main(String[] args) {
		
		test1();
		test2();
		test3();
		test4();
		test5();
		test6();
		
		solve1();
		solve2();
		
	}

	private static void test1() {
		String input = "[1,2,3]";
		int sum = sumNumbers(input);
		output(12,-1,String.valueOf(sum));
	}

	private static void test2() {
		String input = "{\"a\":2,\"b\":4}";
		int sum = sumNumbers(input);
		output(12,-2,String.valueOf(sum));
	}

	private static void test3() {
		String input = "[[[3]]]";
		int sum = sumNumbers(input);
		output(12,-3,String.valueOf(sum));
	}

	private static void test4() {
		String input = "{\"a\":{\"b\":4},\"c\":-1}";
		int sum = sumNumbers(input);
		output(12,-4,String.valueOf(sum));
	}
	
	private static void test5() {
		String input = "{\"a\":[-1,1]}";
		int sum = sumNumbers(input);
		output(12,-5,String.valueOf(sum));
	}

	private static void test6() {
		String input = "[-1,{\"a\":1}]";
		int sum = sumNumbers(input);
		output(12,-6,String.valueOf(sum));
	}
	
	
	private static void solve1() {
		String input = FileIO.getFileAsString(FILENAME);
		int sum = sumNumbers(input);
		output(12,1,String.valueOf(sum));
	}
	
	private static void solve2() {
		String input = FileIO.getFileAsString(FILENAME);
		Object data = getJsonObject(input);
		List filtered = filter(data);
		String filteredJson = formJson(filtered);
		int sum = sumNumbers(filteredJson);
		output(12,2,String.valueOf(sum));
		
		
	}
	
	private static int sumNumbers(String input) {
		return DIGITS.splitAsStream(input)
				.filter(s -> !s.isEmpty())
				.mapToInt(s -> (int)Double.parseDouble(s))
				.sum();
	}
	
	private static void output(int day, int part, String result) {
		System.out.printf("Day %d:\tPart: %d\tResult: %s\n",day,part,result);
	}
	
	private static Object getJsonObject(String input) {
		return new Gson().fromJson(input, Object.class);
	}
	
	private static String formJson(List data) {
		Gson gson = new Gson();
		StringBuilder sb = new StringBuilder();
		gson.toJson(data, sb);
		return sb.toString();
	}
	
	private static List filter(Object data) {
		List<Object> tmp = new ArrayList<>();
		if (data instanceof Map) {
			Collection values = ((Map)data).values();
			if (values.contains("red")) {
				// ignore object
			} else {
				for(Object o : values) {
					tmp.addAll(filter(o)); // add all elements recursively
				}
			}
		} else if (data instanceof List) {
			for(Object o: (List)data) {
				tmp.add(filter(o));
			}
			
		} else {
			tmp.add(data);
		}
		
		return tmp;
	}
}