""" Create 5 new Mwamba loans with different durations to verify interest calculation. """ import os import django from decimal import Decimal os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'branch_system.settings') django.setup() from django.contrib.auth import get_user_model from loans.models import LoanProduct, LoanApplication, Loan from django.utils import timezone User = get_user_model() def create_test_mwamba_loans(): """Create 5 Mwamba loans with different durations""" print("=" * 80) print("CREATING 5 TEST MWAMBA LOANS") print("=" * 80) # Get Mwamba product mwamba = LoanProduct.objects.get(product_type='mwamba') print(f"\nMwamba Product:") print(f" Interest Rate: {mwamba.interest_rate}% per month") print(f" Processing Fee: {mwamba.processing_fee}%") # Get or create borrowers borrowers = [] for i in range(5): borrower = User.objects.filter( username=f'mwamba_test_{i+1}' ).first() if not borrower: borrower = User.objects.create_user( username=f'mwamba_test_{i+1}', email=f'mwamba_test_{i+1}@example.com', password='password123', first_name=f'Mwamba', last_name=f'Test{i+1}', phone_number=f'+25471234567{i}', role='borrower', is_active=True, status='active', monthly_income=Decimal('100000.00') ) print(f" Created borrower: {borrower.get_full_name()}") else: print(f" Using borrower: {borrower.get_full_name()}") borrowers.append(borrower) # Get admin for approval admin = User.objects.filter(role='admin').first() if not admin: admin = User.objects.filter(is_superuser=True).first() # Test cases: (principal, duration_days, description) test_cases = [ (Decimal('50000.00'), 30, "1 month (30 days)"), (Decimal('75000.00'), 60, "2 months (60 days)"), (Decimal('100000.00'), 90, "3 months (90 days)"), (Decimal('150000.00'), 120, "4 months (120 days)"), (Decimal('200000.00'), 180, "6 months (180 days)"), ] print(f"\n" + "=" * 80) print("CREATING LOANS") print("=" * 80) created_loans = [] for idx, (principal, duration_days, description) in enumerate(test_cases): borrower = borrowers[idx] print(f"\n{'-' * 80}") print(f"Loan {idx + 1}: {description}") print(f"{'-' * 80}") # Calculate expected values months = Decimal(str(duration_days)) / Decimal('30') interest_rate = mwamba.interest_rate / Decimal('100') expected_interest = principal * interest_rate * months processing_fee_rate = mwamba.processing_fee / Decimal('100') expected_processing_fee = principal * processing_fee_rate expected_total = principal + expected_interest + expected_processing_fee print(f"\nExpected Calculation:") print(f" Principal: KES {principal:,.2f}") print(f" Duration: {duration_days} days ({months} months)") print(f" Interest: {principal:,.2f} × {mwamba.interest_rate}% × {months} = KES {expected_interest:,.2f}") print(f" Processing Fee: {principal:,.2f} × {mwamba.processing_fee}% = KES {expected_processing_fee:,.2f}") print(f" Total: KES {expected_total:,.2f}") # Create application application = LoanApplication.objects.create( borrower=borrower, loan_product=mwamba, requested_amount=principal, requested_duration=duration_days, purpose=f"Test Mwamba loan - {description}", repayment_method='monthly', status='pending' ) print(f"\nApplication Created: {application.application_number}") print(f" Interest Amount: KES {application.interest_amount:,.2f}") print(f" Processing Fee: KES {application.processing_fee_amount:,.2f}") print(f" Total Amount: KES {application.total_amount:,.2f}") # Verify calculation interest_match = abs(application.interest_amount - expected_interest) < Decimal('0.01') processing_fee_match = abs(application.processing_fee_amount - expected_processing_fee) < Decimal('0.01') total_match = abs(application.total_amount - expected_total) < Decimal('0.01') if interest_match and processing_fee_match and total_match: print(f"\n✓ Calculation CORRECT!") else: print(f"\n✗ Calculation MISMATCH!") if not interest_match: print(f" Interest: Expected {expected_interest:,.2f}, Got {application.interest_amount:,.2f}") if not processing_fee_match: print(f" Processing Fee: Expected {expected_processing_fee:,.2f}, Got {application.processing_fee_amount:,.2f}") if not total_match: print(f" Total: Expected {expected_total:,.2f}, Got {application.total_amount:,.2f}") # Approve and create loan loan = application.approve( approved_by=admin, notes=f"Test loan - {description}", disbursement_date=timezone.now() ) print(f"\nLoan Created: {loan.loan_number}") print(f" Status: {loan.status}") # Verify loan amounts match application loan_match = ( loan.principal_amount == application.requested_amount and loan.interest_amount == application.interest_amount and loan.processing_fee == application.processing_fee_amount and loan.total_amount == application.total_amount ) if loan_match: print(f"✓ Loan amounts match application") else: print(f"✗ Loan amounts don't match application!") created_loans.append({ 'loan': loan, 'principal': principal, 'duration_days': duration_days, 'months': months, 'expected_interest': expected_interest, 'actual_interest': loan.interest_amount, 'description': description }) # Summary print(f"\n" + "=" * 80) print("SUMMARY OF CREATED LOANS") print("=" * 80) print(f"\n{'Loan Number':<15} {'Duration':<12} {'Principal':<15} {'Interest':<15} {'Total':<15} {'Status'}") print("-" * 95) all_correct = True for loan_data in created_loans: loan = loan_data['loan'] expected = loan_data['expected_interest'] actual = loan_data['actual_interest'] match = abs(expected - actual) < Decimal('0.01') status = "✓ CORRECT" if match else "✗ WRONG" if not match: all_correct = False print(f"{loan.loan_number:<15} {loan_data['duration_days']:>3} days KES {loan.principal_amount:>10,.2f} KES {loan.interest_amount:>10,.2f} KES {loan.total_amount:>10,.2f} {status}") print(f"\n" + "=" * 80) print("INTEREST BREAKDOWN VERIFICATION") print("=" * 80) for loan_data in created_loans: loan = loan_data['loan'] months = loan_data['months'] interest_per_month = loan.principal_amount * Decimal('0.10') print(f"\n{loan.loan_number} - {loan_data['description']}:") print(f" Principal: KES {loan.principal_amount:,.2f}") print(f" Interest Rate: 10% per month") print(f" Duration: {loan_data['duration_days']} days = {months} months") print(f" Calculation:") # Show month-by-month breakdown for month in range(1, int(months) + 1): print(f" Month {month}: 10% × KES {loan.principal_amount:,.2f} = KES {interest_per_month:,.2f}") # If there's a partial month if months % 1 != 0: partial = months % 1 partial_interest = loan.principal_amount * Decimal('0.10') * Decimal(str(partial)) print(f" Partial ({partial:.2f} month): 10% × KES {loan.principal_amount:,.2f} × {partial:.2f} = KES {partial_interest:,.2f}") print(f" Total Interest: KES {loan.interest_amount:,.2f}") print(f" Total Amount: KES {loan.total_amount:,.2f}") print(f"\n" + "=" * 80) print("FINAL VERIFICATION") print("=" * 80) if all_correct: print("\n✓✓✓ SUCCESS! ALL 5 LOANS HAVE CORRECT INTEREST CALCULATIONS! ✓✓✓") print("\nThe interest calculation is working perfectly:") print(" • Each month charges exactly 10% of the principal") print(" • Partial months are calculated proportionally") print(" • No rounding errors or incorrect multipliers") print("\nFormula verified: Interest = Principal × 10% × (Days ÷ 30)") else: print("\n✗ SOME LOANS HAVE INCORRECT CALCULATIONS!") print("Please review the calculation logic.") return created_loans if __name__ == '__main__': try: loans = create_test_mwamba_loans() print(f"\n✓ Script completed successfully!") print(f"✓ Created {len(loans)} test loans") except Exception as e: print(f"\n✗ Error: {str(e)}") import traceback traceback.print_exc()