Delete student from tutorial (#89)

* Add code to delete student from tutorial class. Returns true if successful. Also modified the tutorialClass deletion method from ModuleCode to do the same for tutorialClasses

* Hook delete students from tutorial classes command to deleteStudent classes

* Add test cases for email and id

* Refactor code into the abstract DeleteStudent class

src/main/java/seedu/address/logic/commands/deletestudentcommands/DeleteStudentByEmailCommand.java

@@ -11,6 +11,8 @@
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Person;
 
+
+
 /**
  * Deletes a student identified using email from the address book.
  */
@@ -36,6 +38,7 @@ public CommandResult execute(Model model) throws CommandException {
             throw new CommandException(String.format(PersonMessages.MESSAGE_PERSON_EMAIL_NOT_FOUND, email));
         }
         model.deletePerson(personToDelete);
+        deleteStudentFromTutorialClasses(model, personToDelete);
 
         return new CommandResult(String.format(MESSAGE_DELETE_PERSON_SUCCESS, Messages.format(personToDelete)));
     }

src/main/java/seedu/address/logic/commands/deletestudentcommands/DeleteStudentByIdCommand.java

@@ -11,6 +11,8 @@
 import seedu.address.model.person.Person;
 import seedu.address.model.person.StudentId;
 
+
+
 /**
  * Deletes a student identified using student ID from the address book.
  */
@@ -36,6 +38,7 @@ public CommandResult execute(Model model) throws CommandException {
         }
 
         model.deletePerson(personToDelete);
+        deleteStudentFromTutorialClasses(model, personToDelete);
 
         return new CommandResult(String.format(MESSAGE_DELETE_PERSON_SUCCESS, Messages.format(personToDelete)));
     }

src/main/java/seedu/address/logic/commands/deletestudentcommands/DeleteStudentByIndexCommand.java

@@ -11,6 +11,8 @@
 import seedu.address.model.Model;
 import seedu.address.model.person.Person;
 
+
+
 /**
  * Deletes a student identified using index from the address book.
  */
@@ -37,6 +39,7 @@ public CommandResult execute(Model model) throws CommandException {
                     targetIndex.getOneBased()));
         }
         model.deletePerson(personToDelete);
+        deleteStudentFromTutorialClasses(model, personToDelete);
 
         return new CommandResult(String.format(MESSAGE_DELETE_PERSON_SUCCESS, Messages.format(personToDelete)));
     }

src/main/java/seedu/address/logic/commands/deletestudentcommands/DeleteStudentCommand.java

@@ -1,9 +1,16 @@
 package seedu.address.logic.commands.deletestudentcommands;
 
+import java.util.ArrayList;
+
+import javafx.collections.ObservableList;
 import seedu.address.logic.commands.Command;
 import seedu.address.logic.commands.CommandResult;
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.model.Model;
+import seedu.address.model.module.ModuleCode;
+import seedu.address.model.module.TutorialClass;
+import seedu.address.model.person.Person;
+
 
 /**
  * Abstract class for DeleteStudentCommand
@@ -31,4 +38,20 @@ public DeleteStudentCommand() {
     public abstract boolean equals(Object other);
 
     public abstract String toString();
+
+    /**
+     * Deletes a specified student from all tutorial classes from all modules in a model.
+     *
+     * @param model that contains the modules and tutorial classes
+     * @param student to be deleted
+     */
+    public void deleteStudentFromTutorialClasses(Model model, Person student) {
+        ObservableList<ModuleCode> list = model.getAddressBook().getModuleList();
+        for (ModuleCode module : list) {
+            ArrayList<TutorialClass> tutorialClassesOfModule = module.getTutorialClasses();
+            for (TutorialClass tutorialClass : tutorialClassesOfModule) {
+                tutorialClass.deleteStudent(student);
+            }
+        }
+    }
 }

src/main/java/seedu/address/model/module/ModuleCode.java

@@ -156,8 +156,10 @@ public void addTutorialClass(TutorialClass tutorialClass) {
      * The tutorial has to exist to be used in this function.
      *
      * @param tutorialClass name of tutorial class to be deleted.
+     *
+     * @return true if tutorial class was successfully deleted
      */
-    public void deleteTutorialClass(TutorialClass tutorialClass) {
-        tutorialClasses.remove(tutorialClass);
+    public boolean deleteTutorialClass(TutorialClass tutorialClass) {
+        return tutorialClasses.remove(tutorialClass);
     }
 }

src/main/java/seedu/address/model/module/TutorialClass.java

@@ -98,6 +98,15 @@ public void addStudent(Person student) {
         students.add(student);
     }
 
+    /**
+     * Removes a student from the tutorial class if it exists.
+     *
+     * @return true if the student was removed
+     */
+    public boolean deleteStudent(Person student) {
+        return students.remove(student);
+    }
+
     /**
      * Checks if the student is in the tutorial class.
      * @param student

src/test/java/seedu/address/logic/commands/DeleteStudentCommandTest.java

@@ -1,5 +1,6 @@
 package seedu.address.logic.commands;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_AMY;
@@ -22,6 +23,8 @@
 import seedu.address.model.Model;
 import seedu.address.model.ModelManager;
 import seedu.address.model.UserPrefs;
+import seedu.address.model.module.ModuleCode;
+import seedu.address.model.module.TutorialClass;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Person;
 import seedu.address.model.person.StudentId;
@@ -121,4 +124,49 @@ private void showNoPerson(Model model) {
 
         assertTrue(model.getFilteredPersonList().isEmpty());
     }
+
+    @Test
+    public void deleteStudentFromTutorialClasses_success() {
+        //Create modules, tutorial classes and student objects
+        ModuleCode cs2103T = new ModuleCode("CS2103T");
+        ModuleCode cs2101 = new ModuleCode("CS2101");
+        TutorialClass t01 = new TutorialClass("T01");
+        TutorialClass t02 = new TutorialClass("T02");
+        TutorialClass t03 = new TutorialClass("T03");
+        TutorialClass t04 = new TutorialClass("T04");
+
+        Person studentToDelete = model.getFilteredPersonList().get(INDEX_FIRST_PERSON.getZeroBased());
+        Person student2 = model.getFilteredPersonList().get(INDEX_SECOND_PERSON.getZeroBased());
+
+        //assign students to tutorials and tutorials to modules
+        t01.addStudent(studentToDelete);
+        t02.addStudent(student2);
+        t03.addStudent(studentToDelete);
+        t03.addStudent(student2);
+
+        cs2103T.addTutorialClass(t01); //should have 0 people upon deletion
+        cs2103T.addTutorialClass(t02); //should have 1 person upon deletion
+        cs2101.addTutorialClass(t03); //should have 1 person upon deletion
+        cs2101.addTutorialClass(t04); //should have 0 people upon deletion
+
+        model.addModule(cs2103T);
+        model.addModule(cs2101);
+
+        DeleteStudentCommand deleteCommand = new DeleteStudentByIndexCommand(INDEX_FIRST_PERSON);
+
+        String expectedMessage = String.format(DeleteStudentCommand.MESSAGE_DELETE_PERSON_SUCCESS,
+                Messages.format(studentToDelete));
+
+        ModelManager expectedModel = new ModelManager(model.getAddressBook(), new UserPrefs());
+        expectedModel.deletePerson(studentToDelete);
+
+        assertCommandSuccess(deleteCommand, model, expectedMessage, expectedModel);
+        assertEquals(0, t01.getStudents().size());
+        assertEquals(1, t02.getStudents().size());
+        assertEquals(1, t03.getStudents().size());
+        assertEquals(0, t04.getStudents().size());
+        assertEquals(student2, t02.getStudents().get(0));
+        assertEquals(student2, t03.getStudents().get(0));
+
+    }
 }

src/test/java/seedu/address/model/module/ModuleCodeTest.java

@@ -88,4 +88,31 @@ void listTutorialClasses_empty_success() {
         String expectedString = "Tutorials in CS2103T: None!";
         assertEquals(moduleCode.listTutorialClasses(), expectedString);
     }
+
+    @Test
+    void deleteTutorialClass_notInList_failure() {
+
+        // Creating TutorialClass objects
+        TutorialClass tutorialClass1 = new TutorialClass("T01");
+        TutorialClass tutorialClass2 = new TutorialClass("T02");
+
+        ModuleCode moduleCode = new ModuleCode("CS2103T");
+        moduleCode.addTutorialClass(tutorialClass1);
+
+        assertFalse(moduleCode.deleteTutorialClass(tutorialClass2));
+        assertEquals(1, moduleCode.getTutorialClasses().size());
+    }
+
+    @Test
+    void deleteTutorialClass_inList_success() {
+
+        // Creating TutorialClass objects
+        TutorialClass tutorialClass1 = new TutorialClass("T01");
+
+        ModuleCode moduleCode = new ModuleCode("CS2103T");
+        moduleCode.addTutorialClass(tutorialClass1);
+
+        assertTrue(moduleCode.deleteTutorialClass(tutorialClass1));
+        assertEquals(0, moduleCode.getTutorialClasses().size());
+    }
 }

src/test/java/seedu/address/model/module/TutorialClassTest.java

@@ -145,4 +145,46 @@ void testConstructorWithStudents() {
         assertTrue(tutorialClass.getStudents().contains(student1));
         assertTrue(tutorialClass.getStudents().contains(student2));
     }
+
+    @Test
+    void deleteStudent_notInList_failure() {
+        ArrayList<Person> students = new ArrayList<>();
+
+        // Creating Person objects
+        Name name1 = new Name("John");
+        Email email1 = new Email("john@example.com");
+        StudentId stuId1 = new StudentId("A0213333J");
+        Set<Tag> tags1 = new HashSet<>();
+        Person student1 = new Person(name1, email1, stuId1, tags1);
+
+        Name name2 = new Name("Alice");
+        Email email2 = new Email("alice@example.com");
+        StudentId stuId2 = new StudentId("A0145678A");
+        Set<Tag> tags2 = new HashSet<>();
+        Person student2 = new Person(name2, email2, stuId2, tags2);
+
+        students.add(student1);
+
+        TutorialClass tutorialClass = new TutorialClass(VALID_TUTORIAL, students);
+        assertFalse(tutorialClass.deleteStudent(student2));
+        assertEquals(1, tutorialClass.getStudents().size());
+    }
+
+    @Test
+    void deleteStudent_inList_success() {
+        ArrayList<Person> students = new ArrayList<>();
+
+        // Creating Person object
+        Name name1 = new Name("John");
+        Email email1 = new Email("john@example.com");
+        StudentId stuId1 = new StudentId("A0213333J");
+        Set<Tag> tags1 = new HashSet<>();
+        Person student1 = new Person(name1, email1, stuId1, tags1);
+
+        students.add(student1);
+
+        TutorialClass tutorialClass = new TutorialClass(VALID_TUTORIAL, students);
+        assertTrue(tutorialClass.deleteStudent(student1));
+        assertEquals(0, tutorialClass.getStudents().size());
+    }
 }