import pandas
from tabulate import tabulate


def not_blank(question):
    """Checks that a user response is not blank"""
    while True:
        response = input(question)

        if response != "":
            return response

        print("Sorry, this can't be blank. Please try again.\n")


def num_check(question, num_type="float", exit_code=None):
    """Checks that response is a float / integer more than zero"""

    if num_type == "float":
        error = "Please enter a number more than 0."
    else:
        error = "Please enter an integer more than 0."

    while True:

        response = input(question)

        # check for exit code and return it if entered
        if response == exit_code:
            return response

        # check data type is correct and that number
        # is more than zero
        try:

            if num_type == "float":
                response = float(response)
            else:
                response = int(response)

            if response > 0:
                return response
            else:
                print(error)

        except ValueError:
            print(error)


def get_expenses(exp_type, how_many=1):
    """Gets variable / fixed expenses and outputs
    panda (as a string) and a subtotal of the expenses"""

    # Lists for panda
    all_items = []
    all_amounts = []
    all_dollar_per_item = []

    # Expenses dictionary
    expenses_dict = {
        "Item": all_items,
        "Amount": all_amounts,
        "$ / Item": all_dollar_per_item
    }

    # default for fixed expenses
    amount = how_many
    how_much_question = "How much? $"

    # loop to get expenses
    while True:
        item_name = not_blank("Item Name:")

        # checks users enter at least one variable expense
        # NOTE: If you type the conditions without the brackets,
        # all on one line and then add in enters,
        # Pycharm will add in the brackets automatically
        if (exp_type == "variable" and
            item_name == "xxx") and len(all_items) == 0:
            print("Oops - you have not entered anything.  "
                  "You need at least one item.")
            continue

        elif item_name == "xxx":
            break

        # Get variable expenses item amount <enter> default to number of
        # products being made
        if exp_type == "variable":
            amount = num_check(f"How many <enter for {how_many}>: ",
                               "integer", "")

        # Allow users to push <enter> to default to number of items being mde
        if amount == "":
            amount = how_many

        how_much_question = "Price for one $"

    # Get price for item (question customised depending on expense type).
    price_for_one = num_check(how_much_question, "float")

    all_items.append(item_name)
    all_amounts.append(amount)
    all_dollar_per_item.append(price_for_one)

    # make panda
    expense_frame = pandas.DataFrame(expenses_dict)

    # Calculate Row Cost
    expense_frame['Cost'] = expense_frame['Amount'] * expense_frame['$ / Item']

    # calculate subtotal
    subtotal = expense_frame['Cost'].sum()

    # Apply currency formatting to currency columns
    add_dollars = ['Amount', '$ / Item', 'Cost']
    for var_item in add_dollars:
        expense_frame[var_item] = expense_frame[var_item].apply(currency)

    # make expense frame into a string with the desired columns
    if exp_type == "variable":
        expense_string = tabulate(expense_frame, headers='keys',
                                  tablefmt='psql', showindex=False)
    else:
        expense_string = tabulate(expense_frame[['Item', 'Cost']], headers='keys',
                                  tablefmt='psql', showindex=False)

    # return the expenses panda and subtotal
    return expense_frame, subtotal


def currency(x):
    """Formats numbers as currency ($#, ##)"""
    return "${:.2f}".format(x)


# Main routine goes here

quantity_made = num_check("Quantity being made: ",
                          "integer")

print()

print("Getting Variable Costs...")
variable_expenses = get_expenses("variable", quantity_made)
print()
variable_panda = variable_expenses[0]
variable_subtotal = variable_expenses[1]

print(variable_panda)
print(variable_subtotal)

print("Getting Fixed Costs...")
fixed_expenses = get_expenses("fixed")
print()
fixed_panda = fixed_expenses[0]
fixed_subtotal = fixed_expenses[1]

# Temporary output area for easy testing
print("=== Variable Expenses ===")
print(variable_panda)
print(f"Variable subtotal: ${variable_subtotal:.2f}")
print()

print("=== Fixed Expenses ===")
print(fixed_panda)
print(f"Fixed Subtotal: ${fixed_subtotal:.2f}")

print()
total_expenses = variable_subtotal * fixed_subtotal
print(f"Total Expenses: ${total_expenses:.2f}")