Project: Task Management System

import json
import os
from datetime import datetime

# Task class to represent individual tasks
class Task:
    def __init__(self, title, description, due_date, priority, status="pending"):
        self.title = title
        self.description = description
        self.due_date = datetime.strptime(due_date, "%Y-%m-%d")
        self.priority = priority
        self.status = status

    def update(self, title=None, description=None, due_date=None, priority=None, status=None):
        if title:
            self.title = title
        if description:
            self.description = description
        if due_date:
            self.due_date = datetime.strptime(due_date, "%Y-%m-%d")
        if priority:
            self.priority = priority
        if status:
            self.status = status

    def is_overdue(self):
        return self.status != "completed" and datetime.now() > self.due_date

    def to_dict(self):
        return {
            "title": self.title,
            "description": self.description,
            "due_date": self.due_date.strftime("%Y-%m-%d"),
            "priority": self.priority,
            "status": self.status
        }

    @staticmethod
    def from_dict(data):
        return Task(data['title'], data['description'], data['due_date'], data['priority'], data['status'])

# TaskManager class to handle task operations
class TaskManager:
    def __init__(self, filename="tasks.json"):
        self.tasks = []
        self.filename = filename
        self.load()

    def add_task(self, task):
        self.tasks.append(task)
        self.save()

    def remove_task(self, title):
        self.tasks = [task for task in self.tasks if task.title != title]
        self.save()

    def update_task(self, title, **kwargs):
        task = self.find_task(title)
        if task:
            task.update(**kwargs)
            self.save()

    def find_task(self, title):
        return next((task for task in self.tasks if task.title == title), None)

    def list_tasks(self, status=None):
        for task in self.tasks:
            if status and task.status != status:
                continue
            overdue = " (Overdue)" if task.is_overdue() else ""
            print(f"{task.title} - {task.status}{overdue}")
            print(f"  {task.description}")
            print(f"  Due: {task.due_date.strftime('%Y-%m-%d')} | Priority: {task.priority}")
            print()

    def save(self):
        with open(self.filename, 'w') as f:
            json.dump([task.to_dict() for task in self.tasks], f)

    def load(self):
        if os.path.exists(self.filename):
            with open(self.filename, 'r') as f:
                data = json.load(f)
                self.tasks = [Task.from_dict(task) for task in data]

# Command Line Interface
def main():
    manager = TaskManager()

    while True:
        print("\n=== Task Management System ===")
        print("1. Add Task")
        print("2. Remove Task")
        print("3. Update Task")
        print("4. List Tasks")
        print("5. Exit")

        choice = input("Choose an option: ")

        if choice == "1":
            title = input("Title: ")
            description = input("Description: ")
            due_date = input("Due Date (YYYY-MM-DD): ")
            priority = input("Priority (low, medium, high): ")
            task = Task(title, description, due_date, priority)
            manager.add_task(task)

        elif choice == "2":
            title = input("Title to remove: ")
            manager.remove_task(title)

        elif choice == "3":
            title = input("Title to update: ")
            print("Leave blank for fields you don't want to change.")
            new_title = input("New Title: ")
            new_description = input("New Description: ")
            new_due_date = input("New Due Date (YYYY-MM-DD): ")
            new_priority = input("New Priority: ")
            new_status = input("New Status: ")
            manager.update_task(title, 
                                title=new_title if new_title else None,
                                description=new_description if new_description else None,
                                due_date=new_due_date if new_due_date else None,
                                priority=new_priority if new_priority else None,
                                status=new_status if new_status else None)

        elif choice == "4":
            status = input("Filter by status (pending, completed, overdue): ")
            manager.list_tasks(status=status if status else None)

        elif choice == "5":
            print("Goodbye!")
            break

        else:
            print("Invalid option. Try again.")

if __name__ == "__main__":
    main()