eliminated some hardcoded values

app/models/__init__.py

@@ -1,4 +1,8 @@
 from .transactions import Transaction
 from .repayment import Repayment
+from .loan import Loan
+from .loan_charge import LoanCharge
+from .customer import Customer
+from .account import Account
 
-__all__ = ['Transaction', 'Repayment']
+__all__ = ['Transaction', 'Repayment', 'Loan', 'LoanCharge', 'Customer', 'Account']

app/models/account.py

@@ -0,0 +1,25 @@
+from datetime import datetime, timezone
+from sqlalchemy.orm import relationship
+from app.extensions import db
+
+
+class Account(db.Model):
+    __tablename__ = 'accounts'
+
+    id = db.Column(db.String(50), primary_key=True)
+    customer_id = db.Column(db.String(50), nullable=False)
+    account_type = db.Column(db.String(50))
+    status = db.Column(db.String(20), default='active')
+    lien_amount = db.Column(db.Float, default=0.0)
+    created_at = db.Column(db.DateTime, default=datetime.now(timezone.utc))
+    updated_at = db.Column(db.DateTime, default=datetime.now(timezone.utc), onupdate=datetime.now(timezone.utc))
+
+    customer = relationship(
+        "Customer",
+        primaryjoin="Customer.id == Account.customer_id",
+        foreign_keys=[customer_id],
+        back_populates="accounts",
+    )
+
+    def __repr__(self):
+        return f'<Account {self.id}>'

app/models/customer.py

@@ -0,0 +1,41 @@
+from datetime import datetime, timezone
+from sqlalchemy.orm import relationship
+from app.extensions import db
+
+
+class Customer(db.Model):
+    __tablename__ = 'customers'
+
+    id = db.Column(db.String(50), primary_key=True)
+    msisdn = db.Column(db.String(20), unique=True, nullable=False)
+    country_code = db.Column(db.String(3), nullable=False)
+    created_at = db.Column(db.DateTime, default=datetime.now(timezone.utc))
+    updated_at = db.Column(db.DateTime, default=datetime.now(timezone.utc), onupdate=datetime.now(timezone.utc))
+
+    accounts = relationship(
+        "Account",
+        primaryjoin="Customer.id == Account.customer_id",
+        foreign_keys="Account.customer_id",
+        back_populates="customer",
+    )
+
+    loans = relationship(
+        "Loan",
+        primaryjoin="Customer.id == Loan.customer_id",
+        foreign_keys="Loan.customer_id",
+        back_populates="customer",
+    )
+
+    @classmethod
+    def get_customer(cls, customer_id):
+        """
+        Get customer by  ID.
+        """
+        customer = cls.query.filter_by(id=customer_id).first()
+
+        if not customer:
+            raise ValueError(f"Customer does not exist")
+        return customer
+
+    def __repr__(self):
+        return f'<Customer {self.id}>'

app/models/loan.py

@@ -54,6 +54,11 @@ class Loan(db.Model):
             'continuousFee': self.continuous_fee,
             'collectionType': self.collection_type,
             'status': self.status,
+            'productId': self.product_id,
             'dueDate': self.due_date.isoformat() if self.due_date else None,
             'loanDate': self.created_at.isoformat if self.created_at else None
-        }
+        }
+
+    @classmethod
+    def get_loan_by_transaction_id(cls, transaction_id):
+        return cls.query.filter_by(transaction_id=transaction_id).first()

app/models/loan_charge.py

@@ -1,4 +1,6 @@
 from datetime import datetime, timezone, timedelta
+from os.path import devnull
+
 from app.extensions import db
 from sqlalchemy.orm import relationship
 
@@ -40,4 +42,8 @@ class LoanCharge(db.Model):
             'percent': self.percent,
             'description': self.description,
             'due': self.due
-        }
+        }
+
+    @classmethod
+    def get_loan_charge_by_debt_id(cls, debt_id):
+        return cls.query.filter_by(loan_id=debt_id)