def __edit_shared_expense_into_shared(current_user_id, our_expenses, expense, our_accounts, our_users, date, description,
                                      account_id, amount, error, category_id, categories, accounts, users, expense_id,
                                      key=None, dict=None):

    # fetch values and check they are actually provided
    if 'split' in request.form: split = request.form['split']
    else: error = 'You need to provide a % split'
    if 'user' in request.form: shared_with_user = request.form['user']
    else: error = 'You need to provide a user'

    # 'heavier' checks
    if not error:
        # valid percentage split?
        if is_percentage(split):
            # valid user sharing with?
            if our_users.is_connection(user_id=shared_with_user):

                # figure out percentage split
                loaned_amount = round((float(amount) * (100-float(split)))/100, 2)
                loaned_then_amount = round((float(expense[0].amount) * (100-float(expense[3])))/100, 2)

                # is our original and current account the same?
                if expense[0].deduct_from == account_id:
                    # modify the difference between then and now
                    our_accounts.modify_user_balance(amount=expense[0].amount-float(amount), account_id=account_id)
                else:
                    # credit our original account back
                    our_accounts.modify_user_balance(amount=expense[0].amount, account_id=expense[0].deduct_from)

                    # debit from our current account
                    our_accounts.modify_user_balance(amount=-float(amount), account_id=account_id)

                our_loans = Loans(current_user_id)
                their_loans = Loans(expense[2])

                # get slug as a unique identifier
                slug = our_loans.get_loan_slug(loan_id=expense[1])

                # are we sharing the expense with the same user as before?
                if expense[2] == int(shared_with_user):

                    # edit the loan entries
                    our_loans.edit_loan(other_user_id=shared_with_user, account_id=account_id, description=description,
                                        amount=-float(loaned_amount), date=date, loan_id=expense[1])

                    their_loans.edit_loan(other_user_id=current_user_id, amount=loaned_amount, date=date, slug=slug)

                    # modify our loan account balance difference with the user
                    our_accounts.modify_loan_balance(amount=loaned_amount - loaned_then_amount,
                                                     with_user_id=shared_with_user)

                    # now for the user we share with
                    their_expenses = Expenses(shared_with_user)
                    their_accounts = Accounts(shared_with_user)

                    # the user now and then is the same, get their expense
                    their_expense = their_expenses.get_expense(loan_id=expense[1])

                    # modify their loan account balance
                    their_accounts.modify_loan_balance(amount=-loaned_amount + loaned_then_amount,
                                                       with_user_id=current_user_id)

                    # edit their expense amount
                    their_expenses.edit_expense(date=date, account_id=account_id, amount=loaned_amount,
                                                expense_id=their_expense[0].id, pass_thru=True)

                    # update loan links
                    our_expenses.modify_loan_link(loan_id=expense[1], percentage=split, original_amount=amount)
                    their_expenses.modify_loan_link(loan_id=expense[1], percentage=split, original_amount=amount)

                else:
                    # the other user we WERE sharing with
                    their_expenses = Expenses(expense[2])
                    their_accounts = Accounts(expense[2])

                    # credit our loan account
                    our_accounts.modify_loan_balance(amount=-float(loaned_then_amount), with_user_id=expense[2])

                    # fetch their expense
                    their_expense = their_expenses.get_expense(loan_id=expense[1])

                    # delete the shared user's expense
                    their_expenses.delete_expense(expense_id=their_expense[0].id)

                    # modify their loan status towards us
                    their_accounts.modify_loan_balance(amount=loaned_then_amount, with_user_id=current_user_id)

                    # unlink expenses to loan entries
                    our_expenses.unlink_loan(loan_id=expense[1])

                    # delete the original loans
                    our_loans.delete_loan(loan_id=expense[1])
                    their_loans.delete_loan(slug=slug)

                    flash('Loan reverted')

                    # create a loan from us to the new user
                    our_loan_id = our_loans.add_loan(other_user_id=shared_with_user, date=date, account_id=account_id,
                                                 description=description, amount=-float(loaned_amount))

                    # create a loan entry for the new user
                    their_loans = Loans(shared_with_user)
                    their_loan_id = their_loans.add_loan(other_user_id=current_user_id, date=date,
                                                       description=description, amount=loaned_amount)

                    # generate slugs for the new loans
                    our_slugs = Slugs(current_user_id)
                    slug = our_slugs.add_slug(type='loan', object_id=our_loan_id, description=description)
                    their_slugs = Slugs(shared_with_user)
                    their_slugs.add_slug(type='loan', object_id=their_loan_id, slug=slug)

                    flash('Loan given')

                    # modify loan monies for us
                    our_accounts.modify_loan_balance(amount=loaned_amount, with_user_id=shared_with_user)

                    # the CURRENT user we are sharing with
                    their_accounts = Accounts(shared_with_user)

                    # fudge loan 'account' monies for them
                    their_accounts.modify_loan_balance(amount=-float(loaned_amount), with_user_id=current_user_id)

                    their_expenses = Expenses(shared_with_user)

                    # add new expenses (borrower)
                    their_expense_id = their_expenses.add_expense(date=date, amount=loaned_amount,
                                                                  description=description, pass_thru=True)

                    # create new loan - expense links
                    our_expenses.link_to_loan(expense_id=expense_id, loan_id=our_loan_id, shared_with=shared_with_user,
                                              percentage=split, original_amount=amount)
                    their_expenses.link_to_loan(expense_id=their_expense_id, loan_id=our_loan_id, shared_with=current_user_id,
                                                percentage=split, original_amount=amount)

                # edit expense (loaner - us)
                our_expenses.edit_expense(date=date, category_id=category_id, account_id=account_id,
                                          amount=float(amount) - loaned_amount, description=description,
                                          expense_id=expense_id)

                flash('Expense edited')

                # do a GET otherwise category will fail
                return redirect(url_for('expenses.edit_expense', expense_id=expense_id))

            else: error = 'Not a valid user sharing with'
        else: error = 'Not a valid % split'

    # show the form
    return render_template('admin_edit_expense.html', **locals())
Edit a shared expense entry into a shared entry still
dataset/ETHPy150Open radekstepan/FlaskBudget/presenters/expenses.py/__edit_shared_expense_into_shared