from math import ceil

import sqlalchemy
from db import Product, User, Transaction
from text_interface.helpermenus import Menu


class AddStockMenu(Menu):
    def __init__(self):
        Menu.__init__(self, 'Add stock and adjust credit', uses_db=True)
        self.help_text = '''
Enter what you have bought for PVVVV here, along with your user name and how
much money you're due in credits for the purchase when prompted.\n'''
        self.user = None

    def _execute(self):
        questions = {
            (False, False): 'Enter user id or a string of the form "<number> <product>"',
            (False, True): 'Enter user id or more strings of the form "<number> <product>"',
            (True, False): 'Enter a string of the form "<number> <product>"',
            (True, True): 'Enter more strings of the form "<number> <product>", or an empty line to confirm'
        }

        self.user = None
        self.products = {}
        self.price = 0

        while True:
            self.print_info()
            self.printc(questions[bool(self.user), bool(len(self.products))])
            thing_price = 0

            # Read in a 'thing' (product or user):
            line = self.input_multiple(add_nonexisting=('user', 'product'), empty_input_permitted=True,
                                       find_hidden_products=False)

            if line:
                (thing, amount) = line

                if isinstance(thing, Product):
                    self.printc("%d of %s registered" % (amount, thing.name))
                    thing_price = self.input_int('What did you pay a piece? ', (1, 100000),
                                                 default=thing.price) * amount
                    self.price += thing_price

                # once we get something in the
                # purchase, we want to protect the
                # user from accidentally killing it
                self.exit_confirm_msg = 'Abort transaction?'
            else:
                # thing = None

                if not self.complete_input():
                    if self.confirm('Not enough information entered. Abort transaction?', default=True):
                        return False
                    continue

                break

            # Add the thing to the pending adjustments:
            self.add_thing_to_pending(thing, amount, thing_price)

        if self.confirm('Do you want to change the credited amount?', default=False):
            self.price = self.input_int('Total amount> ', (1, 100000), default=self.price)

        self.perform_transaction()

    def complete_input(self):
        return bool(self.user) and len(self.products) and self.price

    def print_info(self):
        print(6 + Product.name_length) * '-'
        if self.price:
            print("Amount to be credited: %" + str(Product.name_length - 17) + "i") % self.price
        if self.user:
            print("User to credit: %" + str(Product.name_length - 10) + "s") % self.user.name
        print('\n%-' + str(Product.name_length - 1) + 's Amount') % "Product"
        print(6 + Product.name_length) * '-'
        if len(self.products):
            # print "Products added:"
            # print (6+Product.name_length)*'-'
            for product in self.products.keys():
                print('%' + str(-Product.name_length) + 's %5i') % (product.name, self.products[product][0])
                print(6 + Product.name_length) * '-'

    def add_thing_to_pending(self, thing, amount, price):
        if isinstance(thing, User):
            if self.user:
                print "Only one user may be credited for a purchase, transfer credit manually afterwards"
                return
            else:
                self.user = thing
        elif thing in self.products.keys():
            print 'Already added this product, adding amounts'
            self.products[thing][0] += amount
            self.products[thing][1] += price
        else:
            self.products[thing] = [amount, price]

    def perform_transaction(self):
        # self.user.credit += self.price
        description = self.input_str('Log message> ', length_range=(0, 50))
        if description == '':
            description = 'Purchased products for PVVVV, adjusted credit ' + str(self.price)
        transaction = Transaction(self.user, -self.price, description)
        transaction.perform_transaction()
        self.session.add(transaction)
        for product in self.products:
            value = max(product.stock, 0) * product.price + self.products[product][1]
            old_price = product.price
            old_hidden = product.hidden
            product.price = int(ceil(float(value) / (max(product.stock, 0) + self.products[product][0])))
            product.stock += self.products[product][0]
            product.hidden = False
            print "New stock for %s: %d" % (product.name, product.stock), \
                ("- New price: " + str(product.price) if old_price != product.price else ""), \
                ("- Removed hidden status" if old_hidden != product.hidden else "")
        try:
            self.session.commit()
            print "Success! Transaction performed:"
            # self.print_info()
            print "User %s's credit is now %i" % (self.user.name, self.user.credit)
        except sqlalchemy.exc.SQLAlchemyError, e:
            print 'Could not perform transaction: %s' % e