Check for duplicate lesson and consult

docs/UserGuide.md

@@ -148,6 +148,104 @@ Examples:
 * `list` followed by `delete 2;3` deletes the 2nd and 3rd student in TAHub.
 * `find n/Betsy` followed by `delete 1` deletes the 1st student in the results of the `find` command.
 
+### Adding a consultation : `addconsult`
+
+Adds a new consultation to TAHub.
+
+**Format**: `addconsult d/DATE t/TIME`
+
+* The date and time should not conflict with any existing consultation.
+* Date format: `YYYY-MM-DD`
+* Time format: `HH:MM`
+
+**Examples**:
+* `addconsult d/2024-10-20 t/14:00`
+* `addconsult d/2024-11-05 t/09:00`
+
+### Listing all consultations : `listconsults`
+
+Displays a list of all consultations in TAHub.
+
+**Format**: `listconsults`
+
+**Example**:
+* `listconsults`
+
+### Adding students to a consultation : `addtoconsult`
+
+Adds students to an existing consultation, specified by its index.
+
+**Format**: `addtoconsult INDEX [n/NAME]... [i/INDEX]...`
+
+* `INDEX` specifies the consultation to add students to.
+* Student names (`n/NAME`) and/or student indices (`i/INDEX`) can be used to specify students.
+* Students already in the consultation will not be added again, and an error message will be shown.
+
+**Examples**:
+* `addtoconsult 1 n/John Doe n/Harry Ng`
+* `addtoconsult 2 i/3 i/5` (adds students at indices 3 and 5 in the student list to the 2nd consultation)
+
+---
+
+### Removing students from a consultation : `removefromconsult`
+
+Removes specified students from a consultation, identified by its index.
+
+**Format**: `removefromconsult INDEX n/NAME...`
+
+* `INDEX` is the index of the consultation from which the students will be removed.
+* Specify one or more students to remove by their names.
+
+**Examples**:
+* `removefromconsult 1 n/John Doe n/Harry Ng` (removes students named John Doe and Harry Ng from the 1st consultation)
+
+---
+
+### Deleting consultations : `deleteconsult`
+
+Deletes one or more consultations from TAHub by their indices.
+
+**Format**: `deleteconsult INDEX[;INDEX]...`
+
+* `INDEX` specifies the consultation to delete. You can delete multiple consultations by separating indices with semicolons (`;`).
+
+**Examples**:
+* `deleteconsult 2`
+* `deleteconsult 1;3;5` (deletes the 1st, 3rd, and 5th consultations)
+
+### Exporting consultations : `exportconsult`
+
+Exports all consultations currently displayed in TAHub to a CSV file.
+
+**Format**: `exportconsult FILENAME [-f]`
+
+* `FILENAME` specifies the name of the CSV file (without the extension).
+* `-f` flag forces overwriting if a file with the same name already exists.
+
+**Examples**:
+* `exportconsult consultations`
+* `exportconsult consultations_backup -f`
+
+**Output**:
+* The file will contain columns for Date, Time, and Students, with students separated by semicolons.
+
+### Importing consultations : `importconsult`
+
+Imports consultations from a specified CSV file into TAHub.
+
+**Format**: `importconsult FILENAME`
+
+* `FILENAME` specifies the file to import consultations from.
+* The file should be in CSV format with columns for Date, Time, and Students.
+* If any entries contain errors (e.g., student not found in TAHub), those entries are recorded in an error file.
+
+**Examples**:
+* `importconsult consultations.csv`
+* `importconsult ~/documents/consultations.csv`
+
+**File Format**:
+* `Date, Time, Students`
+* Each student name should be separated by a semicolon (`;`).
 
 ### Clearing all entries : `clear`
 

src/main/java/seedu/address/logic/commands/consultation/AddConsultCommand.java

@@ -54,6 +54,14 @@
     @Override
     public CommandResult execute(Model model) throws CommandException {
         requireNonNull(model);
+
+        // Check if the model already has a consultation with the same date and time
+        if (model.hasConsult(newConsult)) {
+            throw new CommandException("Duplicate consultation."
+                + " A consultation with this date and time already exists.");
+        }
+
+        // Add the consultation if it's unique
         model.addConsult(newConsult);
         return new CommandResult(String.format(MESSAGE_SUCCESS, Messages.format(newConsult)),
                 COMMAND_TYPE);

src/main/java/seedu/address/logic/commands/lesson/AddLessonCommand.java

@@ -12,6 +12,7 @@
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.model.Model;
 import seedu.address.model.lesson.Lesson;
+import seedu.address.model.lesson.exceptions.DuplicateLessonException;
 
 /**
  * Adds a lesson to the address book.
@@ -54,9 +55,13 @@
     @Override
     public CommandResult execute(Model model) throws CommandException {
         requireNonNull(model);
-        model.addLesson(newLesson);
-        return new CommandResult(String.format(MESSAGE_SUCCESS, Messages.format(newLesson)),
-                COMMAND_TYPE);
+
+        try {
+            model.addLesson(newLesson);
+            return new CommandResult(String.format(MESSAGE_SUCCESS, Messages.format(newLesson)), COMMAND_TYPE);
+        } catch (DuplicateLessonException e) {
+            throw new CommandException("Duplicate lesson. A lesson with this date and time already exists.");
+        }
     }
 
     @Override