add mifos style repayment processor that pays off interest, then principal from most overdue installments first.

mifosng-provider/src/main/java/org/mifosng/platform/loan/domain/CreocoreLoanRepaymentScheduleTransactionProcessor.java

@@ -37,7 +37,8 @@ public class CreocoreLoanRepaymentScheduleTransactionProcessor extends
 	}
 
 	/**
-	 * For early/'in advance' repayments, pays off principal component only.
+	 * For early/'in advance' repayments, pay off in the same way as on-time payments,
+	 * interest first then principal.
 	 */
 	@Override
 	protected Money handleTransactionThatIsPaymentInAdvanceOfInstallment(

mifosng-provider/src/main/java/org/mifosng/platform/loan/domain/LoanRepaymentScheduleTransactionProcessorFactory.java

@@ -8,12 +8,12 @@ public class LoanRepaymentScheduleTransactionProcessorFactory {
 
 	public LoanRepaymentScheduleTransactionProcessor determineProcessor(final LoanTransactionProcessingStrategy transactionProcessingStrategy) {
 
-		LoanRepaymentScheduleTransactionProcessor processor = new HeavensFamilyLoanRepaymentScheduleTransactionProcessor();
+		LoanRepaymentScheduleTransactionProcessor processor = new MifosStyleLoanRepaymentScheduleTransactionProcessor();
 		
 		if (transactionProcessingStrategy != null) {
 			
 			if (transactionProcessingStrategy.isStandardMifosStrategy()) {
-				processor = new HeavensFamilyLoanRepaymentScheduleTransactionProcessor();
+				processor = new MifosStyleLoanRepaymentScheduleTransactionProcessor();
 			}
 			
 			if (transactionProcessingStrategy.isHeavensfamilyStrategy()) {
@@ -31,5 +31,4 @@ public class LoanRepaymentScheduleTransactionProcessorFactory {
 		
 		return processor;
 	}
-
+}
-}

mifosng-provider/src/main/java/org/mifosng/platform/loan/domain/MifosStyleLoanRepaymentScheduleTransactionProcessor.java

@@ -0,0 +1,96 @@
+package org.mifosng.platform.loan.domain;
+
+import java.util.List;
+
+import org.joda.time.LocalDate;
+import org.mifosng.platform.currency.domain.Money;
+
+/**
+ * Old Mifos style {@link LoanRepaymentScheduleTransactionProcessor}.
+ * 
+ * For ALL types of transactions, pays off components in order of interest, then
+ * principal.
+ * 
+ * Other formulas exist on mifos where you can choose 'Declining-Balance Interest Recalculation' which simply
+ * means, recalculate the interest component based on the how much principal is outstanding at a point in time;
+ * but this isnt trying to model that option only the basic one for now.
+ */
+public class MifosStyleLoanRepaymentScheduleTransactionProcessor extends
+		AbstractLoanRepaymentScheduleTransactionProcessor {
+
+	@Override
+	protected boolean isTransactionInAdvanceOfInstallment(
+			final int currentInstallmentIndex,
+			final List<LoanRepaymentScheduleInstallment> installments,
+			final LocalDate transactionDate, final Money transactionAmount) {
+
+		LoanRepaymentScheduleInstallment currentInstallment = installments.get(currentInstallmentIndex);
+
+		return transactionDate.isBefore(currentInstallment.getDueDate());
+	}
+
+	/**
+	 * For early/'in advance' repayments, pay off in the same way as on-time payments,
+	 * interest first then principal.
+	 */
+	@Override
+	protected Money handleTransactionThatIsPaymentInAdvanceOfInstallment(
+			final LoanRepaymentScheduleInstallment currentInstallment,
+			final List<LoanRepaymentScheduleInstallment> installments,
+			final LoanTransaction loanTransaction,
+			final LocalDate transactionDate, final Money paymentInAdvance) {
+		
+		return handleTransactionThatIsOnTimePaymentOfInstallment(currentInstallment, loanTransaction, paymentInAdvance);
+	}
+
+	/**
+	 * For late repayments, pay off in the same way as on-time payments,
+	 * interest first then principal.
+	 */
+	@Override
+	protected Money handleTransactionThatIsALateRepaymentOfInstallment(
+			final LoanRepaymentScheduleInstallment currentInstallment,
+			final List<LoanRepaymentScheduleInstallment> installments,
+			final LoanTransaction loanTransaction,
+			final Money transactionAmountUnprocessed) {
+
+		return handleTransactionThatIsOnTimePaymentOfInstallment(
+				currentInstallment, loanTransaction,
+				transactionAmountUnprocessed);
+	}
+
+	/**
+	 * For normal on-time repayments, pays off interest first, then principal.
+	 */
+	@Override
+	protected Money handleTransactionThatIsOnTimePaymentOfInstallment(
+			final LoanRepaymentScheduleInstallment currentInstallment,
+			final LoanTransaction loanTransaction,
+			final Money transactionAmountUnprocessed) {
+
+		Money transactionAmountRemaining = transactionAmountUnprocessed;
+
+		Money interestPortion = currentInstallment
+				.payInterestComponent(transactionAmountRemaining);
+		transactionAmountRemaining = transactionAmountRemaining
+				.minus(interestPortion);
+
+		Money principalPortion = currentInstallment
+				.payPrincipalComponent(transactionAmountRemaining);
+		transactionAmountRemaining = transactionAmountRemaining
+				.minus(principalPortion);
+
+		Money interestWaivedPortion = Money.zero(transactionAmountRemaining
+				.getCurrency());
+		loanTransaction.updateComponents(principalPortion, interestPortion,
+				interestWaivedPortion);
+
+		return transactionAmountRemaining;
+	}
+
+	@Override
+	protected void onLoanOverpayment(final LoanTransaction loanTransaction,
+			final Money loanOverPaymentAmount) {
+		// dont do anything for with loan over-payment
+	}
+}