# import libraries
import pandas
import math


# functions go here

# checks that input is either a float or and integer that is more than zero.
# takes iin custom error message
def num_check(question, error, num_type):
    valid = False
    while not valid:

        try:
            response = num_type(input(question))

            if response <= 0:
                print(error)
            else:
                return response

        except ValueError:
            print(error)


# checks that user entered either yes or no
def yes_no(question):

    to_check = ['yes', 'no']

    valid = False
    while not valid:

        response = input(question).lower()

        for var_item in to_check:
            if response == var_item:
                return response
            elif response == var_item[0]:
                return var_item

        print("Please enter either yes or no\n")


def not_blank(question, error):

    valid = False
    while not valid:
        response = input(question)

        if response == "":
            print("{}. \nPlease try again.\n".format(error))
            continue

        return response


# currency formatting function
def currency(x):
    return "${:.2f}".format(x)


# gets expenses, returns list which has the data frame and sub total
def get_expenses(var_fixed):
    # set up dictionaries and lists

    item_list = []
    quantity_list = []
    price_list = []

    variable_dict = {
        "Item": item_list,
        "Quantity": quantity_list,
        "Price": price_list
    }
    # loop to get component, quantity and price
    item_name = ""
    while item_name.lower() != "xxx":

        print()
        # get name, quantity and item
        item_name = not_blank("Item name: ",
                              "The component name can't be blank. ")
        if item_name.lower() == "xxx":
            break

        if var_fixed == "variable":
            quantity = num_check("Quantity: ",
                             "The amount must be a whole number more than zero", int)
        else:
            quantity = 1

        price = num_check("How much for a single item? $",
                          "The price must be a whole number more than zero",
                          float)

        # add item, quantity and price to lists
        item_list.append(item_name)
        quantity_list.append(quantity)
        price_list.append(price)

    expense_frame = pandas.DataFrame(variable_dict)
    expense_frame = expense_frame.set_index('Item')

    # calculate cost of each component
    expense_frame['Cost'] = expense_frame['Quantity'] * expense_frame['Price']

    # find sub total
    sub_total = expense_frame['Cost'].sum()

    # currency formatting
    add_dollars = ['Price', 'Cost']
    for item in add_dollars:
        expense_frame[item] = expense_frame[item].apply(currency)

    return [expense_frame, sub_total]


# prints expense frames
def expense_print(heading, frame, subtotal):
    print()
    print("***** {} Costs *****")
    print(frame)
    print()
    print("{} Costs: ${:.2f}".format(heading, subtotal))
    return ""


# work out profit goal and total sales required
def profit_goal(total_costs):

    # initialise variables and error message
    error = "Please enter a valid profit goal\n"

    valid = False
    while not valid:

        # ask for profit goal
        response = input("What is your profit goal? ")

        # check if first character us $
        if response[0] == "$":
            profit_type = "$"
            # get amount (everything after $)
            amount = response[1:]

        # checks if last character is $
        elif response [-1] == "%":
            profit_type = "%"
            # get amount (everything before the %)
            amount = response[:-1]

        else:
            # set response to amount for now
            profit_type = "unknown"
            amount = response

        try:
            # check amount is a number more than zero
            amount = float(amount)
            if amount <= 0:
                print(error)
                continue

        except ValueError:
            print(error)
            continue

        if profit_type == "unknown" and amount >= 100:
            dollar_type = yes_no("Do you mean ${:.2f}? ".format(amount))

            # set profit type based on user answer above
            if dollar_type == "yes":
                profit_type = "$"
            else:
                profit_type = "%"

        elif profit_type == "unknown" and amount < 100:
            percent_type = yes_no("Do you mean {}%? ".format(amount))
            if percent_type == "yes":
                profit_type = "%"
            else:
                profit_type = "$"

        # return profit goal to main routine
        if profit_type == "$":
            return amount
        else:
            goal = (amount / 100) * total_costs
            return goal


# rounding function
def round_up(amount, var_round_to):
    return int(math.ceil(amount / round_to)) * round_to


# main routine goes here
# get product name
product_name = not_blank("Product name: ", "The product name cannot be blank")
how_many = num_check("How many items will you be producing? "
                     "The number of items must be a whole number"
                     "more than zero", int)

print()
print("Please enter your variable costs below")
# get variable costs
variable_expenses = get_expenses("variable")
variable_frame = variable_expenses[0]
variable_sub = variable_expenses[1]

print()
have_fixed = yes_no("Do you have any fixed costs (y/n)? ")

if have_fixed == "yes":
    # get fixed costs
    fixed_expenses = get_expenses("fixed")
    fixed_frame = fixed_expenses[0]
    fixed_sub = fixed_expenses [1]
else:
    fixed_sub = 0

# work out total costs and profit target
all_costs = variable_sub + fixed_sub
profit_target = profit_goal(all_costs)

# calcualtes total sales needed to reach goal
sales_needed = all_costs + profit_target

# ask user for rounding
round_to = num_check("Round to nearest...? $", "Can't be zero", int)

# calculate recommended price
selling_price = sales_needed / how_many
print("Selling Price (unrounded): ${:.2f}".format(selling_price))

# write data to file

# printing area

print()
print("***** Fund Raising - {} *****".format(product_name))
print()
expense_print("Variable", variable_frame, variable_sub)

if have_fixed == "yes":
    expense_print("Fixed", fixed_frame[['Cost']], fixed_sub)

print()
print("***** Total Costs: ${:.2f} *****".format(all_costs))
print()

print()
print("***** Profit & Sales Targets *****")
print("Profit Target: ${:.2f}".format(profit_target))
print("Total Sales: ${:.2f}".format(all_costs + profit_target))

print()
print("***** Recommended Selling Price: ${:.2f} *****".format(selling_price))