Help command

src/main/java/tutorlink/command/HelpCommand.java

@@ -0,0 +1,52 @@
+package tutorlink.command;
+
+import tutorlink.appstate.AppState;
+import tutorlink.commons.Commons;
+import tutorlink.exceptions.TutorLinkException;
+import tutorlink.result.CommandResult;
+
+import java.util.HashMap;
+
+/**
+ * Represents a help command that displays usage information.
+ * This command shows a list of all available commands and their proper usage.
+ * This command is triggered using the "help" keyword.
+ */
+public class HelpCommand extends Command {
+    /**
+     * Command word that triggers this command
+     */
+    public static final String COMMAND_WORD = "help";
+
+    /**
+     * Creates a new HelpCommand instance.
+     */
+    public HelpCommand() {
+    }
+
+    /**
+     * Executes the help command.
+     * Returns a command result containing the help message that lists
+     * all available commands and their usage.
+     *
+     * @param state     The current state of the application
+     * @param arguments Command arguments (not used for help command)
+     * @return CommandResult containing the help message
+     * @throws TutorLinkException if there's an error executing the command
+     */
+    @Override
+    public CommandResult execute(AppState state, HashMap<String, String> arguments) throws TutorLinkException {
+        return new CommandResult(Commons.HELP_MESSAGE);
+    }
+
+    /**
+     * Gets the argument prefixes that this command accepts.
+     * Help command doesn't accept any arguments.
+     *
+     * @return null since this command takes no arguments
+     */
+    @Override
+    public String[] getArgumentPrefixes() {
+        return null;
+    }
+}

src/main/java/tutorlink/commons/Commons.java

@@ -49,4 +49,47 @@ public class Commons {
 
     //Exit
     public static final String EXIT = "Goodbye! See you soon!";
+
+    //Help
+    public static final String HELP_MESSAGE = """
+            -------------------   List of Commands   --------------------
+            help: Displays list of commands
+              Example: help
+
+            add_student: Adds a student to the class roster
+              Example: add_student i/A1234567X n/John Doe
+
+            delete_student: Deletes a student from the class roster
+              Example: delete_student i/A1234567X
+
+            list_student: Lists all students in the class
+              Example: list_student
+
+            find_student: Finds a student in the class roster by name or matric number
+              Example: find_student i/A1234567X n/John Doe
+
+            add_component: Adds a new grading component to the class
+              Example: add_component c/Quiz 1 w/30 m/50
+
+            delete_component: Deletes a grading component from the class
+              Example: delete_component c/Quiz 1
+
+            update_component: Updates a component with a new maxscore or weight
+              Example: update_component c/Quiz 1 w/40 m/60
+
+            list_component: Lists all grading components
+              Example: list_component
+
+            add_grade: Adds a grade for a student for a specific component
+              Example: add_grade i/A1234567X c/Quiz 1 s/45
+
+            delete_grade: Deletes a student's grade for a specific component
+              Example: delete_grade i/A1234567X c/Quiz 1
+
+            list_grade: Lists all grades for a student
+              Example: list_grade i/A1234567X
+
+            bye: Exits the program
+              Example: bye
+            -------------------------------------------------------------""";
 }

src/main/java/tutorlink/parser/Parser.java

@@ -14,7 +14,9 @@
 import tutorlink.command.AddGradeCommand;
 import tutorlink.command.AddComponentCommand;
 import tutorlink.command.UpdateComponentCommand;
+import tutorlink.command.HelpCommand;
 import tutorlink.exceptions.IllegalValueException;
+
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Set;
@@ -91,6 +93,9 @@ public Command getCommand(String line) {
         case ExitCommand.COMMAND_WORD:
             return new ExitCommand();
 
+        case HelpCommand.COMMAND_WORD:
+            return new HelpCommand();
+
         default:
             return new InvalidCommand();
         }
@@ -102,7 +107,7 @@ public Command getCommand(String line) {
      * and are extracted into a map where each prefix is a key and the corresponding argument is the value.
      *
      * @param argumentPrefixes An array of valid argument prefixes (e.g., "n/", "i/").
-     * @param line The user input containing command arguments.
+     * @param line             The user input containing command arguments.
      * @return A {@code HashMap} where keys are prefixes (e.g., "n/", "i/") and values are the corresponding arguments.
      */
     public HashMap<String, String> getArguments(String[] argumentPrefixes, String line) throws IllegalValueException {