Add new flag for viewloan and merge viewloans into viewloan

src/main/java/seedu/address/logic/commands/ViewLoanCommand.java

@@ -14,9 +14,7 @@
 /**
  * Represents a command to view the loans associated with a contact.
  */
-public class ViewLoanCommand extends Command {
-    public static final String COMMAND_WORD = "viewloan";
-
+public class ViewLoanCommand extends ViewLoanRelatedCommand {
     public static final String MESSAGE_USAGE = COMMAND_WORD
             + ": View loans associated with the person identified by the index used in the displayed person list.\n"
             + "Parameters: INDEX (must be a positive integer)\n"
@@ -25,7 +23,14 @@
     public static final String MESSAGE_SUCCESS = "Listed all loans associated with: %1$s";
     private final Index targetIndex;
 
-    public ViewLoanCommand(Index targetIndex) {
+    /**
+     * Creates a ViewLoanCommand to view the loans associated with the person at the specified {@code Index}.
+     *
+     * @param targetIndex The index of the person to view loans for.
+     * @param isShowAllLoans Whether to show all loans or only active loans.
+     */
+    public ViewLoanCommand(Index targetIndex, boolean isShowAllLoans) {
+        super(isShowAllLoans);
         this.targetIndex = targetIndex;
     }
 
@@ -40,7 +45,11 @@
 
         Person personToShowLoan = lastShownList.get(targetIndex.getZeroBased());
         model.updateFilteredPersonList(person -> person.equals(personToShowLoan));
-        model.updateFilteredLoanList(loan -> loan.isAssignedTo(personToShowLoan) && loan.isActive());
+        if (isShowAllLoans) {
+            model.updateFilteredLoanList(loan -> loan.isAssignedTo(personToShowLoan));
+        } else {
+            model.updateFilteredLoanList(loan -> loan.isAssignedTo(personToShowLoan) && loan.isActive());
+        }
         return new CommandResult(String.format(MESSAGE_SUCCESS, Messages.format(personToShowLoan)),
                 false, false, true);
     }

src/main/java/seedu/address/logic/commands/ViewLoanRelatedCommand.java

@@ -0,0 +1,13 @@
+package seedu.address.logic.commands;
+
+/**
+ * Represents a command that is related to viewing loans.
+ */
+public abstract class ViewLoanRelatedCommand extends Command {
+    public static final String COMMAND_WORD = "viewloan";
+    final boolean isShowAllLoans;
+
+    protected ViewLoanRelatedCommand(boolean isShowAllLoans) {
+        this.isShowAllLoans = isShowAllLoans;
+    }
+}

src/main/java/seedu/address/logic/commands/ViewLoansCommand.java

@@ -2,24 +2,32 @@
 
 import static java.util.Objects.requireNonNull;
 import static seedu.address.model.Model.PREDICATE_SHOW_ALL_ACTIVE_LOANS;
+import static seedu.address.model.Model.PREDICATE_SHOW_ALL_LOANS;
 import static seedu.address.model.Model.PREDICATE_SHOW_NO_PERSON;
 
 import seedu.address.model.Model;
 
 /**
  * Lists all active loans in the address book to the user.
  */
-public class ViewLoansCommand extends Command {
+public class ViewLoansCommand extends ViewLoanRelatedCommand {
     public static final String COMMAND_WORD = "viewloans";
 
     public static final String MESSAGE_SUCCESS = "Listed all loans";
 
+    public ViewLoansCommand(boolean isShowAllLoans) {
+        super(isShowAllLoans);
+    }
 
     @Override
     public CommandResult execute(Model model) {
         requireNonNull(model);
         model.updateFilteredPersonList(PREDICATE_SHOW_NO_PERSON);
-        model.updateFilteredLoanList(PREDICATE_SHOW_ALL_ACTIVE_LOANS);
+        if (isShowAllLoans) {
+            model.updateFilteredLoanList(PREDICATE_SHOW_ALL_LOANS);
+        } else {
+            model.updateFilteredLoanList(PREDICATE_SHOW_ALL_ACTIVE_LOANS);
+        }
         return new CommandResult(MESSAGE_SUCCESS, false, false, true);
     }
 }

src/main/java/seedu/address/logic/parser/AddressBookParser.java

@@ -21,8 +21,7 @@
 import seedu.address.logic.commands.LinkLoanCommand;
 import seedu.address.logic.commands.ListCommand;
 import seedu.address.logic.commands.MarkLoanCommand;
-import seedu.address.logic.commands.ViewLoanCommand;
-import seedu.address.logic.commands.ViewLoansCommand;
+import seedu.address.logic.commands.ViewLoanRelatedCommand;
 import seedu.address.logic.parser.exceptions.ParseException;
 
 /**
@@ -88,15 +87,12 @@ public Command parseCommand(String userInput) throws ParseException {
         case HelpCommand.COMMAND_WORD:
             return new HelpCommand();
 
-        case ViewLoanCommand.COMMAND_WORD:
+        case ViewLoanRelatedCommand.COMMAND_WORD:
             return new ViewLoanCommandParser().parse(arguments);
 
         case MarkLoanCommand.COMMAND_WORD:
             return new MarkLoanCommandParser().parse(arguments);
 
-        case ViewLoansCommand.COMMAND_WORD:
-            return new ViewLoansCommand();
-
         case AnalyticsCommand.COMMAND_WORD:
             return new AnalyticsCommandParser().parse(arguments);
 

src/main/java/seedu/address/logic/parser/CliSyntax.java

@@ -15,4 +15,5 @@ public class CliSyntax {
     public static final Prefix PREFIX_START_DATE = new Prefix("s/");
     public static final Prefix PREFIX_RETURN_DATE = new Prefix("r/");
     public static final Prefix PREFIX_LOAN_INDEX = new Prefix("l/");
+    public static final String FLAG_SHOW_ALL_LOANS = "-a";
 }

src/main/java/seedu/address/logic/parser/ViewLoanCommandParser.java

@@ -1,25 +1,43 @@
 package seedu.address.logic.parser;
 
 import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.parser.CliSyntax.FLAG_SHOW_ALL_LOANS;
 
 import seedu.address.commons.core.index.Index;
 import seedu.address.logic.commands.ViewLoanCommand;
+import seedu.address.logic.commands.ViewLoanRelatedCommand;
+import seedu.address.logic.commands.ViewLoansCommand;
 import seedu.address.logic.parser.exceptions.ParseException;
 
 /**
  * Parses input arguments and creates a new ViewLoanCommand object
  */
-public class ViewLoanCommandParser implements Parser<ViewLoanCommand> {
+public class ViewLoanCommandParser implements Parser<ViewLoanRelatedCommand> {
 
     /**
      * Parses the given {@code String} of arguments in the context of the ViewLoanCommand
-     * and returns a ViewLoanCommand object for execution.
+     * and returns a ViewLoanRelatedCommand object for execution.
      * @throws ParseException if the user input does not conform the expected format
      */
-    public ViewLoanCommand parse(String args) throws ParseException {
+    public ViewLoanRelatedCommand parse(String args) throws ParseException {
+        boolean isShowAllLoans = false;
+        String modifiedArgs = args;
+
+        // Check if the user wants to view all loans, active or not
+        if (modifiedArgs.contains(FLAG_SHOW_ALL_LOANS)) {
+            isShowAllLoans = true;
+            modifiedArgs = modifiedArgs.replace(FLAG_SHOW_ALL_LOANS, "").trim();
+        }
+
+        // Check if the user wants to view all loans, i.e. no index is provided
+        if (modifiedArgs.isEmpty()) {
+            return new ViewLoansCommand(isShowAllLoans);
+        }
+
+        // Check if the user wants to view a specific person's loans
         try {
-            Index index = ParserUtil.parseIndex(args);
-            return new ViewLoanCommand(index);
+            Index index = ParserUtil.parseIndex(modifiedArgs);
+            return new ViewLoanCommand(index, isShowAllLoans);
         } catch (ParseException pe) {
             throw new ParseException(
                     String.format(MESSAGE_INVALID_COMMAND_FORMAT, ViewLoanCommand.MESSAGE_USAGE), pe);

src/main/java/seedu/address/model/Model.java

@@ -26,6 +26,11 @@ public interface Model {
      */
     Predicate<Person> PREDICATE_SHOW_NO_PERSON = unused -> false;
 
+    /**
+     * {@code Predicate} that always evaluate to true
+     */
+    Predicate<Loan> PREDICATE_SHOW_ALL_LOANS = unused -> true;
+
     /**
      * {@code Predicate} that evaluates to true if the loan is active
      */