Merge pull request #176 from jantman/cc-min-pymt

Credit Payoff minimum payment fix

CHANGES.rst

@@ -1,6 +1,11 @@
 Changelog
 =========
 
+Unreleased Changes
+------------------
+
+* Fix major logic error in Credit Card Payoff calculations; interest fees were ignored for the current month/statement, resulting in "Next Payment" values significantly lower than they should be. Fixed to use the last Interest Charge retrieved via OFX (or, if no interest charges present in OFX statements, prompt users to manually enter the last Interest Charge via a new modal that will create an OFXTransaction for it) as the interest amount on the first month/statement when calculating payoffs. This fix now returns Next Payment values that aren't identical to sample cards, but are significantly closer (within 1-2%).
+
 0.7.1 (2018-01-10)
 ------------------
 

biweeklybudget/flaskapp/static/js/creditPayoffErrorModal.js

@@ -0,0 +1,72 @@
+/*
+The latest version of this package is available at:
+<http://github.com/jantman/biweeklybudget>
+
+################################################################################
+Copyright 2016 Jason Antman <jason@jasonantman.com> <http://www.jasonantman.com>
+
+    This file is part of biweeklybudget, also known as biweeklybudget.
+
+    biweeklybudget is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    biweeklybudget is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with biweeklybudget.  If not, see <http://www.gnu.org/licenses/>.
+
+The Copyright and Authors attributions contained herein may not be removed or
+otherwise altered, except to add the Author attribution of a contributor to
+this work. (Additional Terms pursuant to Section 7b of the AGPL v3)
+################################################################################
+While not legally required, I sincerely request that anyone who finds
+bugs please submit them at <https://github.com/jantman/biweeklybudget> or
+to me via email, and that you send any contributions or improvements
+either as a pull request on GitHub, or to me via email.
+################################################################################
+
+AUTHORS:
+Jason Antman <jason@jasonantman.com> <http://www.jasonantman.com>
+################################################################################
+*/
+
+/**
+ * Trigger Ajax to get account OFX statement information. Ajax callback to
+ * create the form and display the modal is :js:func:`creditPayoffErrorModalForm`.
+ *
+ * @param {number} acct_id - the ID of the Account to show data for.
+ */
+function creditPayoffErrorModal(acct_id) {
+    $('#modalBody').empty();
+    $.ajax("/ajax/account_ofx_ajax/" + acct_id).done(creditPayoffErrorModalForm);
+}
+
+/**
+ * Generate the HTML for the form on the Credit Payoff Error Modal and show the
+ * modal. This is an Ajax callback triggered by a request to
+ * ``/ajax/account_ofx_ajax/<int:account_id>`` in :js:func:`creditPayoffErrorModal`.
+ * The response data is generated by :py:class:`~.AccountOfxAjax`.
+ */
+function creditPayoffErrorModalForm(data) {
+    var opts = [];
+    for (var idx in data['statements']) {
+        var s = data['statements'][idx];
+        opts.push({ label: s['as_of'] + " (" + fmt_currency(s['ledger_bal']) + ")", value: s['filename'] });
+    }
+    var frm = new FormBuilder('payoffAcctForm')
+        .addHidden('payoff_acct_frm_id', 'id', data['account_id'])
+        .addSelect('payoff_acct_frm_statement_filename', 'filename', 'Statement', opts)
+        .addCurrency('payoff_acct_frm_interest_amt', 'interest_amt', 'Interest Charge');
+    $('#modalBody').append(frm.render());
+    $('#modalSaveButton').off();
+    $('#modalSaveButton').click(function() {
+        handleForm('modalBody', 'payoffAcctForm', '/forms/credit-payoff-account-ofx', null);
+    }).show();
+    $('#modalLabel').text('Add Manual Interest Charge for Account ' + data['account_id']);
+    $("#modalDiv").modal('show');
+}

biweeklybudget/flaskapp/templates/credit-payoffs-no-interest-error.html

@@ -0,0 +1,23 @@
+{% extends "base.html" %}
+{% block title %}ERROR - Credit Card Payoffs - BiweeklyBudget{% endblock %}
+{% block body %}
+{% include 'notifications.html' %}
+            <div class="row">
+                <div class="col-lg-12">
+                    <div class="alert alert-danger" id="account-interest-error-message">
+                        <p><strong>Account Interest Error.</strong></p>
+                        <p>The account "<a href="/accounts/{{ acct_id }}">{{ acct_name }}</a>" (ID <a href="/accounts/{{ acct_id }}">{{ acct_id }}</a>) does not have a record of Interest Charged in the last 32 days. Credit card payments cannot be calculated without this information. Either this software does not know how to find the interest charges in your account's OFX statements (in which case you should <a href="https://github.com/jantman/biweeklybudget/issues">open an issue on GitHub</a>) or your financial institution (such as Discover Cards) does not report interest charges in their OFX statements, in which case you must <a href="#" onclick="creditPayoffErrorModal({{ acct_id }})">manually input the interest charge from your last statement</a>.</p>
+                    </div>
+                </div>
+                <!-- /.col-lg-12 -->
+            </div>
+{% include 'modal.html' %}
+{% endblock %}
+{% block extra_foot_script %}
+<script src="/utils/datetest.js"></script>
+<script src="/static/bootstrap-datepicker/js/bootstrap-datepicker.js"></script>
+<script src="/static/js/custom.js"></script>
+<script src="/static/js/forms.js"></script>
+<script src="/static/js/formBuilder.js"></script>
+<script src="/static/js/creditPayoffErrorModal.js"></script>
+{% endblock %}

biweeklybudget/flaskapp/views/credit_payoffs.py

@@ -38,7 +38,7 @@
 import logging
 import json
 from decimal import Decimal, ROUND_UP
-from datetime import datetime
+from datetime import datetime, timedelta
 
 from flask.views import MethodView
 from flask import render_template, request, jsonify
@@ -48,7 +48,11 @@
 from biweeklybudget.db import db_session
 from biweeklybudget.interest import InterestHelper
 from biweeklybudget.models.dbsetting import DBSetting
-from biweeklybudget.utils import fmt_currency
+from biweeklybudget.utils import fmt_currency, dtnow
+from biweeklybudget.models.account import NoInterestChargedError, Account
+from biweeklybudget.models.ofx_statement import OFXStatement
+from biweeklybudget.models.ofx_transaction import OFXTransaction
+from biweeklybudget.flaskapp.views.formhandlerview import FormHandlerView
 
 logger = logging.getLogger(__name__)
 
@@ -145,9 +149,17 @@ def get(self):
         else:
             pymt_settings_json = setting.value
         pymt_settings_kwargs = self._payment_settings_dict(pymt_settings_json)
-        ih = InterestHelper(db_session, **pymt_settings_kwargs)
-        mps = sum(ih.min_payments.values())
-        payoffs = self._payoffs_list(ih)
+        try:
+            ih = InterestHelper(db_session, **pymt_settings_kwargs)
+            mps = sum(ih.min_payments.values())
+            payoffs = self._payoffs_list(ih)
+        except NoInterestChargedError as ex:
+            resp = render_template(
+                'credit-payoffs-no-interest-error.html',
+                acct_name=ex.account.name,
+                acct_id=ex.account.id
+            )
+            return resp, 500
         return render_template(
             'credit-payoffs.html',
             monthly_pymt_sum=mps.quantize(Decimal('.01'), rounding=ROUND_UP),
@@ -201,6 +213,89 @@ def post(self):
         })
 
 
+class AccountOfxAjax(MethodView):
+    """
+    Handle GET /ajax/account_ofx_ajax/<int:account_id> endpoint.
+    """
+
+    def get(self, account_id):
+        res = []
+        q = db_session.query(OFXStatement).filter(
+            OFXStatement.account_id.__eq__(account_id)
+        ).order_by(
+            OFXStatement.as_of.desc(),
+            OFXStatement.file_mtime.desc()
+        ).all()
+        for stmt in q:
+            if stmt.as_of < (dtnow() - timedelta(days=32)):
+                break
+            res.append({
+                'filename': stmt.filename,
+                'as_of': stmt.as_of.strftime('%Y-%m-%d'),
+                'ledger_bal': stmt.ledger_bal
+            })
+        return jsonify({
+            'account_id': account_id,
+            'statements': res
+        })
+
+
+class AccountOfxFormHandler(FormHandlerView):
+    """
+    Handle POST /forms/credit-payoff-account-ofx
+    """
+
+    def validate(self, data):
+        pass
+
+    def submit(self, data):
+        """
+        Handle form submission; create or update models in the DB. Raises an
+        Exception for any errors.
+
+        :param data: submitted form data
+        :type data: dict
+        :return: message describing changes to DB (i.e. link to created record)
+        :rtype: str
+        """
+        acct = db_session.query(Account).get(int(data['id']))
+        if acct is None:
+            raise RuntimeError('ERROR: No Account with ID %s' % data['id'])
+        stmt = db_session.query(OFXStatement).filter(
+            OFXStatement.account_id.__eq__(acct.id),
+            OFXStatement.filename.__eq__(data['filename'])
+        ).one()
+        if stmt is None:
+            raise RuntimeError(
+                'ERROR: No OFXStatement for account %d with filename %s' % (
+                    acct.id, data['filename']
+                )
+            )
+        int_amt = Decimal(data['interest_amt'])
+        if int_amt < Decimal('0'):
+            int_amt = int_amt * Decimal('-1')
+        trans = OFXTransaction(
+            account=acct,
+            statement=stmt,
+            fitid='%s-MANUAL-CCPAYOFF' % dtnow().strftime('%Y%m%d%H%M%S'),
+            trans_type='debit',
+            date_posted=stmt.as_of,
+            amount=int_amt,
+            name='Interest Charged - MANUALLY ENTERED',
+            is_interest_charge=True
+        )
+        logger.info(
+            'Adding manual interest transaction to OFXTransactions: '
+            'account_id=%d statement_filename=%s statement=%s '
+            'OFXTransaction=%s', acct.id, data['filename'], stmt,
+            trans
+        )
+        db_session.add(trans)
+        db_session.commit()
+        return 'Successfully saved OFXTransaction with FITID %s in database' \
+               '.' % trans.fitid
+
+
 app.add_url_rule(
     '/accounts/credit-payoff',
     view_func=CreditPayoffsView.as_view('credit_payoffs_view')
@@ -209,3 +304,11 @@ def post(self):
     '/settings/credit-payoff',
     view_func=PayoffSettingsFormHandler.as_view('payoff_settings_form')
 )
+app.add_url_rule(
+    '/ajax/account_ofx_ajax/<int:account_id>',
+    view_func=AccountOfxAjax.as_view('account_ofx_ajax')
+)
+app.add_url_rule(
+    '/forms/credit-payoff-account-ofx',
+    view_func=AccountOfxFormHandler.as_view('payoff_account_ofx_form')
+)

biweeklybudget/interest.py

@@ -41,7 +41,7 @@
 from dateutil.relativedelta import relativedelta
 from calendar import monthrange
 
-from biweeklybudget.models import Account, AcctType
+from biweeklybudget.models.account import Account, AcctType
 
 logger = logging.getLogger(__name__)
 
@@ -119,7 +119,7 @@ def _make_statements(self, accounts):
                 min_pay_cls,
                 bill_period,
                 end_balance=abs(acct.balance.ledger),
-                interest_amt=Decimal('0')
+                interest_amt=acct.last_interest_charge
             )
         logger.debug('Statements: %s', res)
         return res

biweeklybudget/models/account.py

@@ -39,13 +39,15 @@
 from sqlalchemy import (
     Column, Integer, String, Boolean, Text, Enum, Numeric, inspect, or_
 )
+from datetime import timedelta
 from sqlalchemy.ext.hybrid import hybrid_property
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql.expression import null
 
 from biweeklybudget.models.base import Base, ModelAsDict
 from biweeklybudget.models.account_balance import AccountBalance
 from biweeklybudget.models.transaction import Transaction
+from biweeklybudget.models.ofx_transaction import OFXTransaction
 from biweeklybudget.utils import dtnow
 from biweeklybudget.prime_rate import PrimeRateCalculator
 import json
@@ -55,6 +57,19 @@
 logger = logging.getLogger(__name__)
 
 
+class NoInterestChargedError(Exception):
+    """
+    Exception raised when an :py:class:`~.Account` does not have an
+    OFXTransaction for interest charged within the last 32 days.
+    """
+
+    def __init__(self, acct):
+        self.account = acct
+        super(NoInterestChargedError, self).__init__(
+            'Could not find last interest charge for account %s' % self
+        )
+
+
 class AcctType(enum.Enum):
     Bank = 1
     Credit = 2
@@ -308,3 +323,32 @@ def effective_apr(self):
                 self.prime_rate_margin
             )
         return self.apr
+
+    @property
+    def last_interest_charge(self):
+        """
+        Return the amount of the last interest charge for this account. Raise an
+        exception if one could not be identified.
+
+        :return: amount of last interest charge for this account
+        :rtype: decimal.Decimal
+        """
+        sess = inspect(self).session
+        for t in sess.query(OFXTransaction).filter(
+            OFXTransaction.account_id.__eq__(self.id)
+        ).order_by(
+            OFXTransaction.date_posted.desc()
+        ):
+            if t.trans_type != 'debit':
+                continue
+            if 'interest charge' not in t.name.lower():
+                continue
+            if t.date_posted < (dtnow() - timedelta(days=32)):
+                continue
+            logger.debug(
+                'Account %s found last interest charge as %s (%s)',
+                self, (t.amount * -1), t
+            )
+            return t.amount * -1
+        logger.warning('Could not find last interest charge for: %s', self)
+        raise NoInterestChargedError(self)