= Teacher Class Creation Process =

== Step 1 - System Login ==
The teacher logs into the system by entering their **email** and **password**. The password is hashed and checked against the database.

{{{
SELECT id_user, username 
FROM User 
WHERE email = :input_email AND password = :hashed_input_pass;
}}}
''Note:'' `:hashed_input_pass` is securely hashed before being checked.

---

== Step 2 - Teacher Dashboard ==
After logging in, the teacher can see the **subjects** and **classes** they are assigned to.

=== List Subjects Assigned to the Teacher ===
{{{
SELECT DISTINCT s.id_subject, s.name AS subject_name
FROM Teacher t
JOIN Course c ON t.id_teacher = c.created_by
JOIN Subject_Course sc ON c.id_Course = sc.id_Course
JOIN Subject s ON sc.id_subject = s.id_subject
WHERE t.id_user = :curr_usr_id;
}}}
Displays all subjects the teacher is responsible for.

=== List Teacher’s Upcoming Classes ===
{{{
SELECT cl.id_class, cl.start_time, cl.end_time, cl.duration, c.id_Course, s.name AS subject_name
FROM Class cl
JOIN Teacher t ON cl.teacher_id = t.id_teacher
JOIN Course_Class cc ON cl.id_class = cc.id_class
JOIN Course c ON cc.id_Course = c.id_Course
JOIN Subject_Course sc ON c.id_Course = sc.id_Course
JOIN Subject s ON sc.id_subject = s.id_subject
WHERE t.id_user = :curr_usr_id AND cl.start_time >= CURRENT_TIME;
}}}
Lists upcoming classes assigned to the teacher.

---

== Step 3 - Creating a New Class ==
The teacher clicks the **"Create New Class"** button and is redirected to a form to enter class details.

---

== Step 4 - Filling Out the Class Creation Form ==
The teacher selects:  
 * **Subject** – From the list of subjects they teach.  
 * **Start Time** – Class start time (`HH:MM:SS`).  
 * **End Time** – Class end time (`HH:MM:SS`).  
 * **Duration** – Automatically calculated based on start and end time.  
 * **Course** – The course that this class belongs to.  

=== Retrieve Subjects for Selection ===
{{{
SELECT DISTINCT s.id_subject, s.name 
FROM Subject s
JOIN Subject_Course sc ON s.id_subject = sc.id_subject
JOIN Course c ON sc.id_Course = c.id_Course
WHERE c.created_by = :curr_teacher_id;
}}}

---

== Step 5 - Submitting the Class to the Database ==
After filling in the form, the system inserts the new class record.

=== Insert New Class ===
{{{
INSERT INTO Class (id_class, start_time, end_time, duration, teacher_id)
VALUES (:id_class, :start_time, :end_time, TIMESTAMPDIFF(MINUTE, :start_time, :end_time), :teacher_id);
}}}
''Duration is automatically calculated using TIMESTAMPDIFF().''

=== Link the Class to a Course ===
{{{
INSERT INTO Course_Class (id_Course, id_class)
VALUES (:selected_course_id, :id_class);
}}}
Links the new class to an existing course.

---

== Step 6 - Confirmation & Viewing the Schedule ==
Once the new class is created, the teacher can view their **updated schedule**.

=== Retrieve Updated Class Schedule ===
{{{
SELECT cl.id_class, cl.start_time, cl.end_time, cl.duration, s.name AS subject_name
FROM Class cl
JOIN Course_Class cc ON cl.id_class = cc.id_class
JOIN Course c ON cc.id_Course = c.id_Course
JOIN Subject_Course sc ON c.id_Course = sc.id_Course
JOIN Subject s ON sc.id_subject = s.id_subject
WHERE cl.teacher_id = :curr_teacher_id
ORDER BY cl.start_time ASC;
}}}
Shows all upcoming classes assigned to the teacher.

---

== Step 7 - Managing Classes ==
Teachers can **modify** or **cancel** classes if needed.

=== Cancel a Class ===
{{{
DELETE FROM Class WHERE id_class = :id_class;
}}}
Completely removes the class from the schedule.

=== Update Class Timing ===
{{{
UPDATE Class 
SET start_time = :new_start_time, 
    end_time = :new_end_time, 
    duration = TIMESTAMPDIFF(MINUTE, :new_start_time, :new_end_time)
WHERE id_class = :id_class;
}}}
Updates the class timing dynamically.

---

== Conclusion ==
This **step-by-step process** allows teachers to:  
✔ Log in to the system.  
✔ View their subjects and assigned classes.  
✔ Create new classes and link them to courses.  
✔ View and manage their schedule.