aoc22day07

public class Main {

    public static void main(String[] args) throws IOException {

        // Reads input and loads into the ElfFileSystem using the
        List<String> data = IOUtils.readInputFile("day07input");
        ElfFileSystem fs = new ElfFileSystem(data);

        //  Generates a map with all the paths in the ElfFileSystem with its whole size
        Map<Path, Integer> pathSize = fs.getElfFileSystemPaths().stream()
                .collect(Collectors.toMap(i -> i, fs::getPathContentSize));

        // --------- Part 1, my input answer 1350966 ---------
        int part1 = pathSize.values().stream().filter(i -> i < 100000).mapToInt(i -> i).sum();
        System.out.println("Part 1: " + part1);

        //  --------- Part 2, my input answer 6296435 ---------
        int neededSpace = pathSize.values().stream()
                .sorted(Comparator.reverseOrder()).limit(1)
                .findFirst().orElse(-1) + 30000000 - 70000000;

        int part2 = pathSize.values().stream().filter(i -> i >= neededSpace)
                .mapToInt(i -> i)
                .sorted()
                .limit(1).findFirst().orElse(-1);
        System.out.println("Part 2: " + part2);
    }
}

public class FSElement {

    private final int size;
    private final Path path;

    public FSElement(String fileName, Path path) {
        if (Character.isDigit(fileName.charAt(0))) {
            this.size = Integer.parseInt(fileName.split(" ")[0]);
        } else {
            this.size = 0;
        }
        this.path = path;
    }

    public long getSize() {
        return this.size;
    }

    public Path getPath() {
        return this.path;
    }
}

public class ElfFileSystem {

    private final List<FSElement> elements;
    private Path currentPath;

    public ElfFileSystem(List<String> data) {
        currentPath = Path.of(File.separator);
        elements = new ArrayList<>();
        for (String line : data) {
            if (line.startsWith("$ cd")) {
                setPath(line.split(" ")[2]);
            } else if (!line.startsWith("$ ls")) {
                elements.add(new FSElement(line, currentPath));
            }
        }
    }

    private void setPath(String goTo) {
        if (goTo.equals("..")) {
            currentPath = currentPath.getParent();
        } else if (goTo.equals("/")) {
            currentPath = Path.of(File.separator);
        } else {
            currentPath = Path.of(currentPath.toString() + File.separator + goTo);
        }
    }

    public int getPathContentSize(Path path) {
        int size = 0;
        for (FSElement element : elements) {
            if (element.getPath().toString().contains(path.toString())) {
                size += element.getSize();
            }
        }
        return size;
    }

    public Set<Path> getElfFileSystemPaths() {
        return elements.stream().map(FSElement::getPath).collect(Collectors.toSet());
    }
}