Task 5

public class FileBackedTasksManager extends InMemoryTaskManager {
    private final Path pathToSave;
    private static final String HEADER = "ID,TYPE,NAME,STATUS,DESCRIPTION,EPIC\n";
    private static int id = 0;

    private FileBackedTasksManager(String file) {
        this.pathToSave = Paths.get(file);
    }

    public static void main(String[] args) throws IOException {
        FileBackedTasksManager fileBackedTasksManager = new FileBackedTasksManager("src/files/file.csv");

        // Создаем экземпляры задач
        Task task1 = new Task(fileBackedTasksManager.calcId(), "taskName_1", "taskDescription_1");
        Task task2 = new Task(fileBackedTasksManager.calcId(), "taskName_2", "taskDescription_2");
        Epic epic1 = new Epic(fileBackedTasksManager.calcId(), "epicTaskName_1", "epicTaskDescription_1");
        Subtask subtask11 = new Subtask(fileBackedTasksManager.calcId(), "subTaskName_11", "subTaskDescription_11");
        Subtask subtask12 = new Subtask(fileBackedTasksManager.calcId(), "subTaskName_12", "subTaskDescription_12");
        Task task3 = new Task(fileBackedTasksManager.calcId(), "taskName_3", "taskDescription_3");

        // Добавляем задачи в мапы
        fileBackedTasksManager.putTask(task1);
        fileBackedTasksManager.putTask(task2);
        fileBackedTasksManager.putTask(task3);
        fileBackedTasksManager.putEpicTask(epic1);
        fileBackedTasksManager.putSubTask(epic1, subtask11);
        fileBackedTasksManager.putSubTask(epic1, subtask12);

        // Обновляем задачи
        fileBackedTasksManager.updateTask(1, task1, Status.IN_PROGRESS);
        fileBackedTasksManager.updateEpicTask(3, epic1);
        fileBackedTasksManager.updateSubTask(4, subtask11, Status.IN_PROGRESS);

        // Печатаем списки задачи
        System.out.println("Печать списков задач после изменений");
        fileBackedTasksManager.getTaskMap().forEach((key, value) -> System.out.println(key + " " + value));
        fileBackedTasksManager.getEpicTaskMap().forEach((key, value) -> System.out.println(key + " " + value));
        fileBackedTasksManager.getSubTaskMap().forEach((key, value) -> System.out.println(key + " " + value));
        System.out.println();

        //Вызов истории
        fileBackedTasksManager.getTaskByID(1);
        fileBackedTasksManager.getTaskByID(3);
        fileBackedTasksManager.getTaskByID(4);
        fileBackedTasksManager.getTaskByID(1);
        fileBackedTasksManager.getTaskByID(6);

        System.out.println("Печать истории");
        fileBackedTasksManager.history().forEach(System.out::println);
        System.out.println();

        fileBackedTasksManager.removeFromHistory(6);
        System.out.println("Печать истории после удаления задачи id 6 из истории");
        fileBackedTasksManager.history().forEach(System.out::println);
        System.out.println();

        // Восстанавливаем менеджер из файла
        System.out.println("Восстанавливаем менеджер задач");
        File file = new File("src/files/file.csv");
        FileBackedTasksManager restoredManager = loadFromFile(file);

        System.out.println("Печать восстановленных задач (проверка)");
        restoredManager.getTaskMap().forEach((key, value) -> System.out.println(key + " " + value));
        restoredManager.getEpicTaskMap().forEach((key, value) -> System.out.println(key + " " + value));
        restoredManager.getSubTaskMap().forEach((key, value) -> System.out.println(key + " " + value));
        System.out.println();

        System.out.println("Печать строки истории просмотров");
        System.out.println(toString(fileBackedTasksManager.history));
        System.out.println(fromStringHistory(toString(fileBackedTasksManager.history)));
        System.out.println();

        System.out.println("Печать восстановленной истории просмотров");
        restoredManager.history().forEach(System.out::println);
        System.out.println();

        System.out.println("Печать нового id, с которого начнется отсчет новых задач");
        System.out.println(id);
        System.out.println();

        System.out.println("Для проверки создадим новую задачу taskName_7 в restoredManager и распечатаем все задачи");
        Task task7 = new Task(restoredManager.calcId(), "taskName_7", "task_Description_7");
        restoredManager.putTask(task7);
        restoredManager.getAllTasks().forEach((key, value) -> System.out.println(key + " " + value));
    }

    private static FileBackedTasksManager loadFromFile(File file) throws IOException {
        FileBackedTasksManager restoredManager = new FileBackedTasksManager(file.getPath());
        List<String> fileLines = Files.readAllLines(Path.of(file.getPath()));
        for (int i = 1; i < (fileLines.size()); i++) {
            if (i < fileLines.size() - 2) {
                addTask(restoredManager, fileLines.get(i));
            } else if (i == (fileLines.size() - 1)) {
                List<Integer> history = fromStringHistory(fileLines.get(i));
                for (Integer elem : history) {
                    restoredManager.getTaskByID(elem);
                }
            }
        }
        String[] lastTaskLine = fileLines.get(fileLines.size() - 3).trim().split(",");
        id = Integer.parseInt(lastTaskLine[0]);
        return restoredManager;
    }
}