run.py

from datetime import datetime
import gspread
from oauth2client.service_account import ServiceAccountCredentials
from colorama import Fore, Style, init
from tabulate import tabulate
from simple_term_menu import TerminalMenu

init(autoreset=True)


def date_validation(date_str):
    """
    Function to validate date. The date should be in YYYY-MM-DD format.
    Otherwise, print an error message and prompt user to input the correct
    format.
    """
    while True:
        try:
            datetime.strptime(date_str, "%Y-%m-%d")
            return date_str
        except ValueError:
            date_str = input(
                f"{Fore.RED}Invalid date format! Please enter the date in "
                "YYYY-MM-DD format. (If you don't enter a date, today's date "
                "will be recorded): "
                )


def amount_validation(amount_str):
    """
    Function to validate amount. The amount should be a positive integer.
    Otherwise, print an error message and allow user to input a positive int.
    """
    while True:
        try:
            amount = int(amount_str)
            if amount < 0:
                raise ValueError(f"{Fore.RED}The amount cannot be negative.")
            return amount
        except ValueError:
            amount_str = input(
                f"{Fore.RED}Invalid amount! Please enter a positive whole "
                "number: "
                               )


def description_validation(description):
    """
    Function to validate the description.
    The description should be a string and not a number.
    Otherwise, give an error message and prompt the user to insert a string.
    """
    while True:
        if description.isdigit():
            description = input(
                f"{Fore.RED}Invalid description! Please enter a valid "
                "description that is not a number: "
            )
        elif len(description) < 3:
            description = input(
                f"{Fore.RED}Invalid description! Description should be at "
                "least 3 characters long. Please try again: "
            )
        else:
            return description


def connect_to_google_sheets(my_finance_tracker):
    """Connect to Google Spreadsheet using gspread library."""
    SCOPE = [
        'https://spreadsheets.google.com/feeds',
        'https://www.googleapis.com/auth/drive.file',
        'https://www.googleapis.com/auth/drive'
    ]

    CREDS = ServiceAccountCredentials.from_json_keyfile_name(
        'creds.json', SCOPE
    )
    CLIENT = gspread.authorize(CREDS)
    SHEET = CLIENT.open(my_finance_tracker).sheet1
    return SHEET


def load_data_from_sheets(SHEET):
    """Load data from Google Sheets."""
    data = SHEET.get_all_records()
    income = 0
    expenses = []
    for record in data:
        if record["Type"] == "Income":
            income = record["Amount"]
        else:
            expenses.append(
                (
                    record["Description"],
                    record["Amount"],
                    record["Date"]
                )
            )
    return income, expenses


def save_data_to_sheets(SHEET, income, income_date, expenses):
    """
    Function to add all data to Google Spreadsheet.
    Add loaded data to sheet rows.
    """
    SHEET.clear()
    SHEET.append_row(["Type", "Description", "Amount", "Date"])
    SHEET.append_row(["Income", "", income, income_date])
    for desc, amount, date in expenses:
        SHEET.append_row(["Expense", desc, amount, date])


def add_income():
    """
    Function to allow user to add income as an integer.
    Print f-string to the user with the income entered.
    """
    income = amount_validation(input(f"{Fore.YELLOW}Enter your income: "))
    income_date = date_validation(
        input(
            f"{Fore.YELLOW}Enter the date of the income earned (YYYY-MM-DD). "
            "(If you don't enter a date, today's date will be recorded): "
            )
        or datetime.today().strftime("%Y-%m-%d")
    )
    print(
        f"{Fore.GREEN}You have successfully entered an income of €{income} "
        f"on {income_date}"
    )
    return income, income_date


def add_expenses():
    """
    Function to allow user to input expenses in a loop until the input is
    'exit'. Enter amount as a number and append the expense description and
    amount. Confirm each expense by yes or no.
    """
    expenses = []
    while True:
        description = description_validation(
            input(
                f"{Fore.YELLOW}Enter an expense description (or type 'exit' "
                "to go back ""to the Main Menu): "
            )
        )
        if description.lower() == 'exit':
            break
        amount = amount_validation(
            input(
                f"{Fore.YELLOW}Enter the expense amount: "
            )
        )
        expense_date = date_validation(
            input(
                f"{Fore.YELLOW}Enter the date of this expense (YYYY-MM-DD). "
                "(If you don't enter a date, today's date will be recorded): "
                ) or datetime.today().strftime('%Y-%m-%d')
            )
        confirmation = input(
            f"{Fore.GREEN}Did you mean '{description}' with an amount of "
            f" €{amount}  on {expense_date}? Type 'yes or no' to confirm: "
        ).lower()
        if confirmation == 'yes':
            expenses.append((description, amount, expense_date))
            print(
                f"{Fore.GREEN}Expense '{description}' of €{amount} spent on "
                f"{expense_date} has been successfully added!"
            )
        else:
            print(
                f"{Fore.YELLOW}Expense {Fore.RED}not added {Fore.YELLOW}"
                "because you did not choose 'yes'."
            )
    return expenses


def show_budget(income, expenses):
    """
    Function to calculate the budget by adding total expenses and subtracting
    total expenses from income to get savings. Print on the terminal the
    income, total expenses, and savings. Display expenses in a table.
    """
    total_expenses = sum([amt for desc, amt, date in expenses])
    savings = income - total_expenses
    print(
        "The current budget of your expenses are: \n"
        "Expense description, amount and date are on the table below."
    )
    print(
        f"""
Income: €{income}
Expenses: €{total_expenses}
Savings: €{savings}
    """
    )

    expense_table = [[desc, amt, date] for desc, amt, date in expenses]
    print(
        tabulate(
            expense_table,
            headers=["Description", "Amount", "Date"],
            tablefmt="grid"
        )
    )


def main():
    """
    Function for the Main Menu with 4 options available to the user: 1-4.
    Otherwise, the option is invalid and the user is requested to try again.
    """
    income = 0
    income_date = None
    expenses = []

    SHEET = connect_to_google_sheets("my_finance_tracker")
    income, expenses = load_data_from_sheets(SHEET)

    print(
        f"{Fore.CYAN}Welcome to My Finance Tracker!\nA program to help you "
        "monitor and manage your finances.\nChoose one of the options below "
        "to get started.\nIncome and Expenses are saved when exiting the "
        "program."
    )

    while True:
        options = ["Add Income", "Add Expenses", "Show Current Budget", "Exit"]
        terminal_menu = TerminalMenu(options)
        choice = terminal_menu.show()

        if choice == 0:
            income, income_date = add_income()
        elif choice == 1:
            expenses = add_expenses()
        elif choice == 2:
            show_budget(income, expenses)
        elif choice == 3:
            print(
                f"{Fore.CYAN}Saving data to Google Spreadsheets...\nStandby."
            )
            save_data_to_sheets(SHEET, income, income_date, expenses)
            print(f"{Fore.CYAN}Exiting program...\nGoodbye!")
            break


if __name__ == "__main__":
    main()