Added new banking system

tools/bank.py

@@ -0,0 +1,110 @@
+import logging
+from datetime import datetime
+from typing import Union
+
+import dataset
+import discord
+
+from tools import database
+
+log = logging.getLogger(__name__)
+
+
+class Bank:
+    def __init__(self, user: Union[discord.User, discord.Member, discord.ClientUser]):
+        # Note: discord.ClientUser is the bot itself.
+        if not isinstance(user, (discord.User, discord.Member, discord.ClientUser)):
+            raise TypeError(
+                f"Object given was not a User nor Member object.\n\tType given: {type(user)}"
+            )
+        self.user = user
+        self.balance = self.__balance__()
+
+    def __str__(self) -> str:
+        """<name>'s balance is $<balance>."""
+
+        return f"{self.user.name}'s balance is **$`{self.balance}`**."
+
+    def __format__(self, format_spec: str) -> str:
+        """Returns balance's value as to the specified format."""
+
+        return format(self.balance, format_spec)
+
+    def __get__(self) -> float:
+        """Returns balance's value as a float."""
+
+        return float(self.balance)
+
+    def __balance__(self) -> float:
+        """Get the balance of a user."""
+
+        with dataset.connect(database.get_db()) as db:
+            # Find last bank transaction.
+            statement = statement = f"""
+                SELECT opening_balance, transaction_amount
+                FROM bank
+                WHERE author_id = {self.user.id}
+                ORDER BY timestamp
+                LIMIT 12
+                """
+            result = db.query(statement)
+            db.close()
+
+        for row in result:
+            balance = row["opening_balance"] + row["transaction_amount"]
+            break
+        else:
+            # If there was no result for the user, default balance is given.
+            balance = 500
+
+        return float(balance)
+
+    def add(self, amount: float, reason: str = "") -> "Bank":
+        """Add to a user's balance."""
+
+        if amount == 0:  # Pointless, do nothing.
+            return 0
+
+        self.__record_ledger__(amount, reason)
+        self.balance += amount
+        return self
+
+    def subtract(self, amount: float, reason: str = "") -> "Bank":
+        """Subtract from a user's balance."""
+
+        if amount == 0:  # Pointless, do nothing.
+            return 0
+
+        self.__record_ledger__(amount, reason)
+        self.balance -= amount
+        return self
+
+    def set(self, amount: float, reason: str = "") -> "Bank":
+        """Set a user's balance."""
+
+        self.__record_ledger__(amount - self.balance, reason)  # Because math
+        self.balance = amount
+        return self
+
+    def __record_ledger__(self, amount: float, reason: str = "") -> None:
+        with dataset.connect(database.get_db()) as db:
+            # Find last bank transaction
+            db["bank"].insert(
+                dict(
+                    author_id=self.user.id,
+                    opening_balance=self.balance,
+                    transaction_amount=amount,
+                    reason=reason,
+                    timestamp=datetime.now(),
+                )
+            )
+            db.commit()
+            db.close()
+
+    def name(self) -> str:
+        """Return bank owner's name."""
+        return self.user.name
+
+    def id(self) -> int:
+        """Return bank owner's ID."""
+        return self.user.id

tools/database.py

@@ -51,5 +51,14 @@ def setup_db():
         stonks.create_column("investment_cost", db.types.float)
         stonks.create_column("timestamp", db.types.datetime)
 
+        # Create bank table and columns to store bank transactions.
+        stonks = db.create_table("bank")
+        stonks.create_column("author_id", db.types.bigint)
+        stonks.create_column("opening_balance", db.types.float)
+        stonks.create_column("transaction_amount", db.types.float)
+        stonks.create_column("reason", db.types.text, default="")
+        stonks.create_column("timestamp", db.types.datetime)
+
         db.commit()
+        db.close()
     log.info("Created tables and columns.")