Implemented receipt generation, including unit tests.

matemat/db/facade.py

@@ -4,11 +4,13 @@ from typing import List, Optional, Any, Type
 
 import crypt
 from hmac import compare_digest
+from datetime import datetime, timedelta
 
-from matemat.db.primitives import User, Product, ReceiptPreference
+from matemat.db.primitives import User, Product, ReceiptPreference, Receipt,\
+    Transaction, Consumption, Deposit, Modification
 from matemat.exceptions import AuthenticationError, DatabaseConsistencyError
 from matemat.db import DatabaseWrapper
-from matemat.db.wrapper import Transaction
+from matemat.db.wrapper import DatabaseTransaction
 
 
 class MatematDatabase(object):
@@ -46,7 +48,7 @@ class MatematDatabase(object):
         # Pass context manager stuff through to the database wrapper
         self.db.__exit__(exc_type, exc_val, exc_tb)
 
-    def transaction(self, exclusive: bool = True) -> Transaction:
+    def transaction(self, exclusive: bool = True) -> DatabaseTransaction:
         """
         Begin a new SQLite3 transaction (exclusive by default).  You should never need to use the returned object (a
         Transaction instance).  It is provided in case there is a real need for it (e.g. for unit testing).
@@ -251,8 +253,7 @@ class MatematDatabase(object):
                 'tkhash': tkhash
             })
 
-    def change_user(self, user: User, agent: Optional[User], **kwargs)\
-            -> None:
+    def change_user(self, user: User, agent: Optional[User], **kwargs) -> None:
         """
         Commit changes to the user in the database.  If writing the requested changes succeeded, the values are updated
         in the provided user object.  Otherwise the user object is left untouched.  The user to update is identified by
@@ -506,6 +507,9 @@ class MatematDatabase(object):
             if affected != 1:
                 raise DatabaseConsistencyError(
                     f'increment_consumption should affect 1 products row, but affected {affected}')
+        # Reflect the change in the user and product objects
+        user.balance -= price
+        product.stock -= 1
 
     def restock(self, product: Product, count: int) -> None:
         """
@@ -526,6 +530,8 @@ class MatematDatabase(object):
             affected = c.execute('SELECT changes()').fetchone()[0]
             if affected != 1:
                 raise DatabaseConsistencyError(f'restock should affect 1 products row, but affected {affected}')
+        # Reflect the change in the product object
+        product.stock += count
 
     def deposit(self, user: User, amount: int) -> None:
         """
@@ -538,17 +544,19 @@ class MatematDatabase(object):
         if amount < 0:
             raise ValueError('Cannot deposit a negative value')
         with self.db.transaction() as c:
-            c.execute('''SELECT username FROM users WHERE user_id = ?''',
+            c.execute('''SELECT balance FROM users WHERE user_id = :user_id''',
                       [user.id])
-            if c.fetchone() is None:
+            row = c.fetchone()
+            if row is None:
                 raise DatabaseConsistencyError(f'No such user: {user.id}')
+            old_balance: int = row[0]
             c.execute('''
             INSERT INTO transactions (user_id, value, old_balance)
               VALUES (:user_id, :value, :old_balance)
             ''', {
                 'user_id': user.id,
                 'value': amount,
-                'old_balance': user.balance
+                'old_balance': old_balance
             })
             c.execute('''
             INSERT INTO deposits (ta_id)
@@ -565,3 +573,84 @@ class MatematDatabase(object):
             affected = c.execute('SELECT changes()').fetchone()[0]
             if affected != 1:
                 raise DatabaseConsistencyError(f'deposit should affect 1 users row, but affected {affected}')
+        # Reflect the change in the user object
+        user.balance = old_balance + amount
+
+    def check_receipt_due(self, user: User) -> bool:
+        if user.receipt_pref == ReceiptPreference.NONE or user.email is None:
+            return False
+        with self.db.transaction() as c:
+            c.execute('''
+            SELECT COALESCE(MAX(r.date), u.created)
+            FROM users AS u
+            LEFT JOIN receipts AS r
+              ON r.user_id = u.user_id
+            WHERE u.user_id = :user_id
+            ''', [user.id])
+        last_receipt: int = c.fetchone()[0]
+        if user.receipt_pref == ReceiptPreference.MONTHLY:
+            date_diff: int = timedelta(days=31).total_seconds()
+        elif user.receipt_pref == ReceiptPreference.YEARLY:
+            date_diff = timedelta(days=365).total_seconds()
+        else:
+            raise ValueError()
+        return datetime.utcnow().timestamp() > last_receipt + date_diff
+
+    def create_receipt(self, user: User, write: bool = False) -> Receipt:
+        transactions: List[Transaction] = []
+        with self.db.transaction() as cursor:
+            cursor.execute('''
+            SELECT COALESCE(MAX(r.date), u.created), COALESCE(MAX(r.last_ta_id), 0)
+            FROM users AS u
+            LEFT JOIN receipts AS r
+              ON r.user_id = u.user_id
+            WHERE u.user_id = :user_id
+            ''', [user.id])
+            row = cursor.fetchone()
+            if row is None:
+                raise DatabaseConsistencyError(f'No such user: {user.id}')
+            fromdate, min_id = row
+            created: datetime = datetime.fromtimestamp(fromdate)
+            cursor.execute('''
+            SELECT t.ta_id, t.value, t.old_balance, t.date, c.ta_id, d.ta_id, m.ta_id, c.product, m.agent, m.reason 
+            FROM transactions AS t
+            LEFT JOIN consumptions AS c
+              ON t.ta_id = c.ta_id
+            LEFT JOIN deposits AS d
+              ON t.ta_id = d.ta_id
+            LEFT JOIN modifications AS m
+              ON t.ta_id = m.ta_id
+            WHERE t.user_id = :user_id
+              AND t.ta_id > :min_id
+            ORDER BY t.date ASC
+            ''', {
+                'user_id': user.id,
+                'min_id': min_id
+            })
+            rows = cursor.fetchall()
+            for row in rows:
+                ta_id, value, old_balance, date, c, d, m, c_prod, m_agent, m_reason = row
+                if c == ta_id:
+                    t: Transaction = Consumption(ta_id, user, value, old_balance, datetime.fromtimestamp(date), c_prod)
+                elif d == ta_id:
+                    t = Deposit(ta_id, user, value, old_balance, datetime.fromtimestamp(date))
+                elif m == ta_id:
+                    t = Modification(ta_id, user, value, old_balance, datetime.fromtimestamp(date), m_agent, m_reason)
+                else:
+                    t = Transaction(ta_id, user, value, old_balance, datetime.fromtimestamp(date))
+                transactions.append(t)
+            if write:
+                cursor.execute('''
+                INSERT INTO receipts (user_id, first_ta_id, last_ta_id)
+                  VALUES (:user_id, :first_ta, :last_ta) 
+                ''', {
+                    'user_id': user.id,
+                    'first_ta': transactions[0].id,
+                    'last_ta': transactions[-1].id
+                })
+                cursor.execute('''SELECT last_insert_rowid()''')
+                receipt_id: int = int(cursor.fetchone()[0])
+            else:
+                receipt_id = -1
+        receipt = Receipt(receipt_id, transactions, user, created, datetime.utcnow())
+        return receipt

matemat/db/primitives/Receipt.py

@@ -0,0 +1,17 @@
+
+from typing import List
+from dataclasses import dataclass
+
+from datetime import datetime
+
+from matemat.db.primitives import User, Transaction
+
+
+@dataclass
+class Receipt:
+
+    id: int
+    transactions: List[Transaction]
+    user: User
+    from_date: datetime
+    to_date: datetime

matemat/db/primitives/ReceiptPreference.py

@@ -26,11 +26,6 @@ class ReceiptPreference(Enum):
     """
     NONE = 0, 'No receipts'
 
-    """
-    A receipt should be generated for each transaction.
-    """
-    EACH = 1, 'Individual receipt per transaction'
-
     """
     A receipt should be generated once a month.
     """

matemat/db/primitives/Transaction.py

@@ -0,0 +1,72 @@
+
+from typing import Optional
+from dataclasses import dataclass
+
+from datetime import datetime
+
+from matemat.db.primitives import User
+from matemat.util.currency_format import format_chf
+
+
+@dataclass(frozen=True)
+class Transaction:
+
+    id: int
+    user: User
+    value: int
+    old_balance: int
+    date: datetime
+
+    @property
+    def receipt_date(self) -> str:
+        date: str = self.date.strftime('%d.%m.%Y, %H:%M')
+        return date
+
+    @property
+    def receipt_value(self) -> str:
+        value: str = format_chf(self.value, with_currencysign=False, plus_sign=True).rjust(8)
+        return value
+
+    @property
+    def receipt_description(self) -> str:
+        return 'Unidentified transaction'
+
+    @property
+    def receipt_message(self) -> Optional[str]:
+        return None
+
+
+@dataclass(frozen=True)
+class Consumption(Transaction):
+
+    product: str
+
+    @property
+    def receipt_description(self) -> str:
+        return self.product
+
+
+@dataclass(frozen=True)
+class Deposit(Transaction):
+
+    @property
+    def receipt_description(self) -> str:
+        return 'Deposit'
+
+
+@dataclass(frozen=True)
+class Modification(Transaction):
+
+    agent: str
+    reason: Optional[str]
+
+    @property
+    def receipt_description(self) -> str:
+        return f'Balance modified by {self.agent}'
+
+    @property
+    def receipt_message(self) -> Optional[str]:
+        if self.reason is None:
+            return None
+        else:
+            return f'Reason: «{self.reason}»'

matemat/db/primitives/__init__.py

@@ -5,3 +5,5 @@ This package provides the 'primitive types' the Matemat software deals with - na
 from .User import User
 from .Product import Product
 from .ReceiptPreference import ReceiptPreference
+from .Transaction import Transaction, Consumption, Deposit, Modification
+from .Receipt import Receipt

matemat/db/test/test_facade.py

@@ -2,9 +2,11 @@
 import unittest
 
 import crypt
+from datetime import datetime, timedelta
 
 from matemat.db import MatematDatabase
-from matemat.db.primitives import User, ReceiptPreference
+from matemat.db.primitives import User, Product, ReceiptPreference, Receipt,\
+    Transaction, Modification, Deposit, Consumption
 from matemat.exceptions import AuthenticationError, DatabaseConsistencyError
 
 
@@ -389,3 +391,186 @@ class DatabaseTest(unittest.TestCase):
                 db.increment_consumption(user1, florapowermate)
             with self.assertRaises(DatabaseConsistencyError):
                 db.increment_consumption(user2, clubmate)
+
+    def test_check_receipt_due(self):
+        with self.db as db:
+            # Receipt preference set to 0
+            user0 = db.create_user('user0', 'supersecurepassword', 'user0@example.com', True, True)
+            # No email, no receipts
+            user1 = db.create_user('user1', 'supersecurepassword', None, True, True)
+            db.change_user(user1, agent=None, receipt_pref=ReceiptPreference.MONTHLY)
+            # Should receive a receipt, has never received a receipt before
+            user2 = db.create_user('user2', 'supersecurepassword', 'user2@example.com', True, True)
+            db.change_user(user2, agent=None, receipt_pref=ReceiptPreference.MONTHLY)
+            # Should receive a receipt, has received receipts before
+            user3 = db.create_user('user3', 'supersecurepassword', 'user3@example.com', True, True)
+            db.change_user(user3, agent=None, receipt_pref=ReceiptPreference.MONTHLY)
+            # Shouldn't receive a receipt, a month hasn't passed since the last receipt
+            user4 = db.create_user('user4', 'supersecurepassword', 'user4@example.com', True, True)
+            db.change_user(user4, agent=None, receipt_pref=ReceiptPreference.MONTHLY)
+            # Should receive a receipt, has been more than a year since the last receipt
+            user5 = db.create_user('user5', 'supersecurepassword', 'user5@example.com', True, True)
+            db.change_user(user5, agent=None, receipt_pref=ReceiptPreference.YEARLY)
+            # Shouldn't receive a receipt, a year hasn't passed since the last receipt
+            user6 = db.create_user('user6', 'supersecurepassword', 'user6@example.com', True, True)
+            db.change_user(user6, agent=None, receipt_pref=ReceiptPreference.YEARLY)
+            # Invalid receipt preference, should raise a ValueError
+            user7 = db.create_user('user7', 'supersecurepassword', 'user7@example.com', True, True)
+            user7.receipt_pref = 42
+
+            twoyears: int = int((datetime.utcnow() - timedelta(days=730)).timestamp())
+            halfyear: int = int((datetime.utcnow() - timedelta(days=183)).timestamp())
+            twomonths: int = int((datetime.utcnow() - timedelta(days=61)).timestamp())
+            halfmonth: int = int((datetime.utcnow() - timedelta(days=15)).timestamp())
+
+            with db.transaction() as c:
+                # Fix creation date for user2
+                c.execute('''
+                UPDATE users SET created = :twomonths WHERE user_id = :user2
+                ''', {
+                    'twomonths': twomonths,
+                    'user2': user2.id
+                })
+                # Create transactions
+                c.execute('''
+                INSERT INTO transactions (ta_id, user_id, value, old_balance, date) VALUES
+                  (1, :user0, 4200, 0, :twomonths),
+                  (2, :user0, 100, 4200, :halfmonth),
+                  (3, :user1, 4200, 0, :twomonths),
+                  (4, :user1, 100, 4200, :halfmonth),
+                  (5, :user2, 4200, 0, :twomonths),
+                  (6, :user2, 100, 4200, :halfmonth),
+                  (7, :user3, 4200, 0, :twomonths),
+                  (8, :user3, 100, 4200, :halfmonth),
+                  (9, :user4, 4200, 0, :twomonths),
+                  (10, :user4, 100, 4200, :halfmonth),
+                  (11, :user5, 4200, 0, :twoyears),
+                  (12, :user5, 100, 4200, :halfyear),
+                  (13, :user6, 4200, 0, :twoyears),
+                  (14, :user6, 100, 4200, :halfyear)
+                ''', {
+                    'twoyears': twoyears,
+                    'halfyear': halfyear,
+                    'twomonths': twomonths,
+                    'halfmonth': halfmonth,
+                    'user0': user0.id,
+                    'user1': user1.id,
+                    'user2': user2.id,
+                    'user3': user3.id,
+                    'user4': user4.id,
+                    'user5': user5.id,
+                    'user6': user6.id
+                })
+                # Create receipts
+                c.execute('''
+                INSERT INTO receipts (user_id, first_ta_id, last_ta_id, date) VALUES
+                  (:user3, 7, 7, :twomonths),
+                  (:user4, 9, 9, :halfmonth),
+                  (:user5, 11, 11, :twoyears),
+                  (:user6, 13, 13, :halfyear)
+                ''', {
+                    'twoyears': twoyears,
+                    'halfyear': halfyear,
+                    'twomonths': twomonths,
+                    'halfmonth': halfmonth,
+                    'user3': user3.id,
+                    'user4': user4.id,
+                    'user5': user5.id,
+                    'user6': user6.id
+                })
+
+            self.assertFalse(db.check_receipt_due(user0))
+            self.assertFalse(self.db.check_receipt_due(user1))
+            self.assertTrue(self.db.check_receipt_due(user2))
+            self.assertTrue(self.db.check_receipt_due(user3))
+            self.assertFalse(self.db.check_receipt_due(user4))
+            self.assertTrue(self.db.check_receipt_due(user5))
+            self.assertFalse(self.db.check_receipt_due(user6))
+            with self.assertRaises(ValueError):
+                self.db.check_receipt_due(user7)
+
+    def test_create_receipt(self):
+        with self.db as db:
+
+            now: datetime = datetime.utcnow()
+            admin: User = db.create_user('admin', 'supersecurepassword', 'admin@example.com', True, True)
+            user: User = db.create_user('user', 'supersecurepassword', 'user@example.com', True, True)
+            product: Product = db.create_product('Flora Power Mate', 200, 200)
+
+            # Create some transactions
+            db.change_user(user, agent=admin,
+                           receipt_pref=ReceiptPreference.MONTHLY,
+                           balance=4200, balance_reason='Here\'s a gift!')
+            db.increment_consumption(user, product)
+            db.deposit(user, 1337)
+            receipt1: Receipt = db.create_receipt(user, write=True)
+
+            with db.transaction() as c:
+                c.execute('SELECT COUNT(receipt_id) FROM receipts')
+                self.assertEqual(1, c.fetchone()[0])
+
+            db.increment_consumption(user, product)
+            db.change_user(user, agent=admin, balance=4200)
+            with db.transaction() as c:
+                # Unknown transactions
+                c.execute('''
+                INSERT INTO transactions (user_id, value, old_balance)
+                SELECT user_id, 500, balance
+                FROM users
+                WHERE user_id = :id
+                ''', [user.id])
+            receipt2: Receipt = db.create_receipt(user, write=False)
+
+            with db.transaction() as c:
+                c.execute('SELECT COUNT(receipt_id) FROM receipts')
+                self.assertEqual(1, c.fetchone()[0])
+
+            self.assertEqual(user, receipt1.user)
+            self.assertEqual(3, len(receipt1.transactions))
+
+            self.assertIsInstance(receipt1.transactions[0], Modification)
+            t10: Modification = receipt1.transactions[0]
+            self.assertEqual(user, receipt1.user)
+            self.assertEqual(4200, t10.value)
+            self.assertEqual(0, t10.old_balance)
+            self.assertEqual(admin.name, t10.agent)
+            self.assertEqual('Here\'s a gift!', t10.reason)
+
+            self.assertIsInstance(receipt1.transactions[1], Consumption)
+            t11: Consumption = receipt1.transactions[1]
+            self.assertEqual(user, receipt1.user)
+            self.assertEqual(-200, t11.value)
+            self.assertEqual(4200, t11.old_balance)
+            self.assertEqual('Flora Power Mate', t11.product)
+
+            self.assertIsInstance(receipt1.transactions[2], Deposit)
+            t12: Deposit = receipt1.transactions[2]
+            self.assertEqual(user, receipt1.user)
+            self.assertEqual(1337, t12.value)
+            self.assertEqual(4000, t12.old_balance)
+
+            self.assertEqual(user, receipt2.user)
+            self.assertEqual(3, len(receipt2.transactions))
+
+            self.assertIsInstance(receipt2.transactions[0], Consumption)
+            t20: Consumption = receipt2.transactions[0]
+            self.assertEqual(user, receipt2.user)
+            self.assertEqual(-200, t20.value)
+            self.assertEqual(5337, t20.old_balance)
+            self.assertEqual('Flora Power Mate', t20.product)
+
+            self.assertIsInstance(receipt2.transactions[1], Modification)
+            t21: Modification = receipt2.transactions[1]
+            self.assertEqual(user, receipt2.user)
+            self.assertEqual(-937, t21.value)
+            self.assertEqual(5137, t21.old_balance)
+            self.assertEqual(admin.name, t21.agent)
+            self.assertEqual(None, t21.reason)
+
+            self.assertIs(type(receipt2.transactions[2]), Transaction)
+            t22: Transaction = receipt2.transactions[2]
+            self.assertEqual(user, receipt2.user)
+            self.assertEqual(500, t22.value)
+            self.assertEqual(4200, t22.old_balance)
+
+# TODO: Test cases for primitive object vs database row mismatch

matemat/db/wrapper.py

@@ -9,7 +9,7 @@ from matemat.db.schemas import SCHEMAS
 from matemat.db.migrations import migrate_schema_1_to_2, migrate_schema_2_to_3
 
 
-class Transaction(object):
+class DatabaseTransaction(object):
 
     def __init__(self, db: sqlite3.Connection, exclusive: bool = True) -> None:
         self._db: sqlite3.Connection = db
@@ -56,10 +56,10 @@ class DatabaseWrapper(object):
     def __exit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
         self.close()
 
-    def transaction(self, exclusive: bool = True) -> Transaction:
+    def transaction(self, exclusive: bool = True) -> DatabaseTransaction:
         if self._sqlite_db is None:
             raise RuntimeError(f'Database connection to {self._filename} is not established.')
-        return Transaction(self._sqlite_db, exclusive)
+        return DatabaseTransaction(self._sqlite_db, exclusive)
 
     def _setup(self) -> None:
         # Enable foreign key enforcement