task_manager.py

from task import Task
from storage import TaskStorage
from datetime import datetime


class TaskManager:
    def __init__(self, storage: TaskStorage):
        self.storage = storage

    def add_task(self, description: str) -> Task:
        # create the new task object
        tasks = self.storage.load_tasks()
        id = max([task.id for task in tasks]) + 1 if tasks else 1
        task = Task(id, description, 'todo', datetime.now().isoformat(), datetime.now().isoformat())
        tasks.append(task)
        self.storage.save_tasks(tasks)
        return task

    def update_task(self, task_id: int, description: str) -> Task:
        tasks = self.storage.load_tasks()
        task = next((task for task in tasks if task.id == task_id), None)
        if task:
            task.description = description
            task.updated_at = datetime.now().isoformat()
            self.storage.save_tasks(tasks)
            return task
        else:
            raise ValueError(f'Task with id {task_id} not found')

    def delete_task(self, task_id: int) -> None:
        tasks = self.storage.load_tasks()
        # filter out tasks with matching id
        new_tasks = [task for task in tasks if task.id != task_id]
        if len(new_tasks) == len(tasks):
            raise ValueError(f'Task with id {task_id} not found')
        self.storage.save_tasks(new_tasks)

    def mark_in_progress(self, task_id: int) -> Task:
        tasks = self.storage.load_tasks()
        task = next((task for task in tasks if task.id == task_id), None)
        if task:
            task.status = 'in-progress'
            task.updated_at = datetime.now().isoformat()
            self.storage.save_tasks(tasks)
            return task
        else:
            raise ValueError(f'Task with id {task_id} not found')

    def mark_done(self, task_id: int) -> Task:
        tasks = self.storage.load_tasks()
        task = next((task for task in tasks if task.id == task_id), None)
        if task:
            task.status = 'done'
            task.updated_at = datetime.now().isoformat()
            self.storage.save_tasks(tasks)
            return task
        else:
            raise ValueError(f'Task with id {task_id} not found')

    def list_tasks(self, status: str = None) -> list[Task]:
        tasks = self.storage.load_tasks()

        if status is None:
            return tasks
        else:
            return [task for task in tasks if task.status == status]