sample.py

import json
import os
import datetime

# --------- Constants ---------
TASKS_FILE = "tasks.json"


# --------- Utility Functions ---------
def clear_console():
    os.system("cls" if os.name == "nt" else "clear")


def pause():
    input("\nPress Enter to continue...")


def load_tasks():
    if not os.path.exists(TASKS_FILE):
        return []
    with open(TASKS_FILE, "r") as f:
        return json.load(f)


def save_tasks(tasks):
    with open(TASKS_FILE, "w") as f:
        json.dump(tasks, f, indent=4)


def generate_task_id(tasks):
    if not tasks:
        return 1
    return max(task["id"] for task in tasks) + 1


def print_task(task):
    print(f"ID: {task['id']}")
    print(f"Title: {task['title']}")
    print(f"Description: {task['description']}")
    print(f"Due Date: {task['due_date']}")
    print(f"Status: {task['status']}")
    print("-" * 40)


def print_tasks(tasks):
    if not tasks:
        print("No tasks found.")
    else:
        for task in tasks:
            print_task(task)


# --------- Core Task Operations ---------
def create_task(tasks):
    clear_console()
    print("Create New Task")
    print("-" * 20)

    title = input("Title: ").strip()
    description = input("Description: ").strip()
    due_date = input("Due Date (YYYY-MM-DD): ").strip()
    status = "Pending"

    task_id = generate_task_id(tasks)
    task = {
        "id": task_id,
        "title": title,
        "description": description,
        "due_date": due_date,
        "status": status
    }
    tasks.append(task)
    save_tasks(tasks)

    print("\nTask created successfully!")
    pause()


def edit_task(tasks):
    clear_console()
    print("Edit Task")
    print("-" * 20)

    task_id = input("Enter Task ID to edit: ").strip()
    if not task_id.isdigit():
        print("Invalid ID.")
        pause()
        return

    task_id = int(task_id)
    for task in tasks:
        if task["id"] == task_id:
            print("\nLeave fields blank to keep current value.\n")
            print_task(task)

            title = input("New Title: ").strip()
            description = input("New Description: ").strip()
            due_date = input("New Due Date (YYYY-MM-DD): ").strip()
            status = input("New Status (Pending/Done): ").strip()

            if title:
                task["title"] = title
            if description:
                task["description"] = description
            if due_date:
                task["due_date"] = due_date
            if status in ["Pending", "Done"]:
                task["status"] = status

            save_tasks(tasks)
            print("\nTask updated successfully!")
            pause()
            return

    print("Task not found.")
    pause()


def delete_task(tasks):
    clear_console()
    print("Delete Task")
    print("-" * 20)

    task_id = input("Enter Task ID to delete: ").strip()
    if not task_id.isdigit():
        print("Invalid ID.")
        pause()
        return

    task_id = int(task_id)
    for i, task in enumerate(tasks):
        if task["id"] == task_id:
            print("Deleting the following task:")
            print_task(task)
            confirm = input("Are you sure? (y/n): ").strip().lower()
            if confirm == "y":
                tasks.pop(i)
                save_tasks(tasks)
                print("Task deleted.")
            else:
                print("Deletion cancelled.")
            pause()
            return

    print("Task not found.")
    pause()


def mark_task_done(tasks):
    clear_console()
    print("Mark Task as Done")
    print("-" * 20)

    task_id = input("Enter Task ID: ").strip()
    if not task_id.isdigit():
        print("Invalid ID.")
        pause()
        return

    task_id = int(task_id)
    for task in tasks:
        if task["id"] == task_id:
            task["status"] = "Done"
            save_tasks(tasks)
            print("Task marked as done.")
            pause()
            return

    print("Task not found.")
    pause()


def search_tasks(tasks):
    clear_console()
    print("Search Tasks")
    print("-" * 20)

    keyword = input("Enter keyword to search: ").strip().lower()

    found_tasks = [
        task for task in tasks
        if keyword in task["title"].lower() or keyword in task["description"].lower()
    ]

    if not found_tasks:
        print("No matching tasks found.")
    else:
        print(f"Found {len(found_tasks)} task(s):\n")
        print_tasks(found_tasks)

    pause()


def show_pending_tasks(tasks):
    clear_console()
    print("Pending Tasks")
    print("-" * 20)

    pending = [task for task in tasks if task["status"] == "Pending"]
    print_tasks(pending)
    pause()


def show_done_tasks(tasks):
    clear_console()
    print("Completed Tasks")
    print("-" * 20)

    done = [task for task in tasks if task["status"] == "Done"]
    print_tasks(done)
    pause()


# --------- Main Menu ---------
def main_menu():
    tasks = load_tasks()

    while True:
        clear_console()
        print("=== Task Manager CLI ===")
        print("1. View All Tasks")
        print("2. Create Task")
        print("3. Edit Task")
        print("4. Delete Task")
        print("5. Mark Task as Done")
        print("6. Search Tasks")
        print("7. View Pending Tasks")
        print("8. View Completed Tasks")
        print("9. Exit")
        print("=========================")

        choice = input("Enter your choice: ").strip()

        if choice == "1":
            clear_console()
            print("All Tasks")
            print("-" * 20)
            print_tasks(tasks)
            pause()
        elif choice == "2":
            create_task(tasks)
        elif choice == "3":
            edit_task(tasks)
        elif choice == "4":
            delete_task(tasks)
        elif choice == "5":
            mark_task_done(tasks)
        elif choice == "6":
            search_tasks(tasks)
        elif choice == "7":
            show_pending_tasks(tasks)
        elif choice == "8":
            show_done_tasks(tasks)
        elif choice == "9":
            print("Exiting Task Manager. Goodbye!")
            break
        else:
            print("Invalid choice.")
            pause()


# --------- Run the App ---------
if __name__ == "__main__":
    main_menu()