task_tracker.py

# build a task tracker, which works from the terminal
# users should be able to:
# add, update, and delete tasks (manage tasks)
# mark a task as in progress or done
# list all the tasks that are done
# list all the tasks that are not done
# list all the tasks that are in progress
# all data should be stored in a JSON File

import json
import os

# JSON file where tasks will be stored
TASKS_FILE = "tasks.json"

tasks = {}


# LOAD TASKS FROM JSON FILE
def load_tasks():
    """
    Loads tasks from the JSON file into the global 'tasks' dictionary.
    If the file does not exist or contains invalid data, we start fresh.
    """
    global tasks

    if os.path.exists(TASKS_FILE):
        try:
            with open(TASKS_FILE, "r") as f:
                tasks = json.load(f)
        except (json.JSONDecodeError, IOError):
            print("Could not read tasks file. Starting with an empty task list.")
            tasks = {}
    else:
        tasks = {}


# SAVE TASKS TO JSON FILE
def save_tasks():
    """
    Saves the current tasks dictionary to the JSON file.
    Ensures data persists between program runs.
    """
    with open(TASKS_FILE, "w") as f:
        json.dump(tasks, f, indent=4)


# ADD A NEW TASK
def add_task():
    """
    Allows the user to create a new task with:
    - name
    - description
    - initial progress status
    """
    task_add = input("\nEnter the name of the new task: ").strip()
    if not task_add:
        print("Task name cannot be empty.")
        return

    # Prevent duplicate task names
    if task_add in tasks:
        print("A task with that name already exists.")
        return

    task_description = input("Enter a description for the task: ").strip()

    print("\nSelect the task's starting progress:")
    print("1) Not done")
    print("2) In progress")
    print("3) Done")
    choice = input("Enter a number (1-3, default 1): ").strip()

    # Determine initial progress state
    if choice == "2":
        task_progression = "in progress"
    elif choice == "3":
        task_progression = "done"
    else:
        task_progression = "not done"

    # Store the new task in the global dictionary
    tasks[task_add] = {
        "description": task_description,
        "progress": task_progression
    }

    save_tasks()
    print(f"\nTask '{task_add}' added.")


# UPDATE AN EXISTING TASK
def update_tasks():
    """
    Allows the user to update:
    - task name (renaming)
    - description
    - progress state
    """
    selected_task = input("\nEnter the name of the task you want to update: ").strip()

    # Ensure task exists
    if selected_task not in tasks:
        print("That task does not exist.")
        return

    print("\nWhat would you like to update?")
    print("1) Task Name")
    print("2) Task Description")
    print("3) Task Progress")

    try:
        choice_selected = int(input("Enter your choice: ").strip())
    except ValueError:
        print("Invalid input. Must be a number.")
        return

    # OPTION 1: RENAME TASK
    if choice_selected == 1:
        new_task_name = input("Enter the new task name: ").strip()

        # Check validity of new name
        if not new_task_name:
            print("Task name cannot be empty.")
            return
        if new_task_name in tasks:
            print("A task with that name already exists.")
            return

        # Move data to new key and remove old key
        tasks[new_task_name] = tasks.pop(selected_task)
        save_tasks()
        print(f"Task renamed to '{new_task_name}'.")

    # OPTION 2: CHANGE DESCRIPTION
    elif choice_selected == 2:
        new_description = input("Enter the new description: ").strip()
        tasks[selected_task]["description"] = new_description
        save_tasks()
        print("Task description updated.")

    # OPTION 3: CHANGE PROGRESS STATE
    elif choice_selected == 3:
        print("\nChoose new progress status:")
        print("1) Not done")
        print("2) In progress")
        print("3) Done")

        prog_choice = input("Enter a number (1-3): ").strip()

        if prog_choice == "1":
            new_progress = "not done"
        elif prog_choice == "2":
            new_progress = "in progress"
        elif prog_choice == "3":
            new_progress = "done"
        else:
            print("Invalid choice.")
            return

        tasks[selected_task]["progress"] = new_progress
        save_tasks()
        print("Task progress updated.")

    else:
        print("Invalid selection.")


# DELETE A TASK
def delete_tasks():
    """
    Deletes a task entirely from the dictionary.
    """
    selected_task = input("\nEnter the name of the task to delete: ").strip()

    if selected_task in tasks:
        tasks.pop(selected_task)
        save_tasks()
        print(f"Task '{selected_task}' deleted.")
    else:
        print("That task does not exist.")


# MANAGE TASKS (ADD / UPDATE / DELETE)
def managing_tasks():
    """
    Menu for general task management.
    """
    print("\nMANAGE TASKS")
    print("1) Add Task")
    print("2) Update Task")
    print("3) Delete Task")

    try:
        management_choice = int(input("Enter your choice: ").strip())
    except ValueError:
        print("Invalid input. Must be a number.")
        return

    if management_choice == 1:
        add_task()
    elif management_choice == 2:
        update_tasks()
    elif management_choice == 3:
        delete_tasks()
    else:
        print("Invalid choice.")


# LIST TASKS (OPTIONALLY FILTERED BY STATUS)
def list_tasks(filter_status=None):
    """
    Lists tasks optionally filtered by:
    - 'not done'
    - 'in progress'
    - 'done'
    """
    if not tasks:
        print("\nNo tasks available.")
        return

    count = 0
    for name, data in tasks.items():
        status = data["progress"]

        # If filter is applied, skip tasks that don't match
        if filter_status and status != filter_status:
            continue

        count += 1
        print(f"\nTASK: {name}")
        print(f"DESCRIPTION: {data['description']}")
        print(f"PROGRESS: {status}")

    if count == 0:
        print("\nNo tasks match that status.")


# STATUS LIST FUNCTIONS
def list_done_tasks():
    print("\nDONE TASKS")
    list_tasks("done")


def list_not_done_tasks():
    print("\nNOT DONE TASKS")
    list_tasks("not done")


def list_in_progress_tasks():
    print("\nIN PROGESS TASKS")
    list_tasks("in progress")


# MAIN MENU LOOP
def main_menu():
    """
    Main menu shown when the program starts.
    Runs until the user chooses to quit.
    """
    load_tasks()  # Load any existing tasks from JSON file

    while True:
        print("\nTASK TRACKER")
        print("1) Manage tasks")
        print("2) List all tasks")
        print("3) List tasks that are done")
        print("4) List tasks that are not done")
        print("5) List tasks that are in progress")
        print("6) Quit")

        choice = input("Choose an option: ").strip()

        if choice == "1":
            managing_tasks()
        elif choice == "2":
            print("\nALL TASKS")
            list_tasks()
        elif choice == "3":
            list_done_tasks()
        elif choice == "4":
            list_not_done_tasks()
        elif choice == "5":
            list_in_progress_tasks()
        elif choice == "6":
            print("Exiting program.")
            break
        else:
            print("Invalid choice. Please try again.")


# PROGRAM ENTRY POINT
if __name__ == "__main__":
    main_menu()