# Session Scheduling Fixes

## Why This Change Exists

The sessions scheduling screen previously allowed free-text period labels and free-text rooms. That made schedules inconsistent, allowed room conflicts, and exposed missing translation keys such as `scheduling.sessions.hide_generator`.

This update makes the scheduling workflow structured and safer while keeping legacy fields as fallback for old sessions.

## Period Rules

Each attendance session now supports a structured `period_type`:

- `morning`: displays as صباحية / Matin.
- `afternoon`: displays as مسائية / Après-midi.
- `custom`: uses `period_label_ar` and `period_label_fr` when provided.

Legacy `slot_label_ar` and `slot_label_fr` are still written for backward compatibility, but new forms use the structured period fields.

## Rooms Management

Rooms are managed independently in `/admin/rooms`.

The `rooms` table stores:

- Arabic/French names.
- Optional code.
- Optional capacity.
- Optional Arabic/French location.
- Active/inactive status.

New sessions and generated schedules use `attendance_sessions.room_id`. Legacy `room_ar` and `room_fr` remain as display fallback for older records.

## Validation Rules

Manual session creation and update now require:

- `period_type` in `morning`, `afternoon`, or `custom`.
- `room_id` pointing to an existing room.
- Valid date and start/end time.
- End time after start time.
- Duration between 30 and 360 minutes.
- No overlap inside the same cohort.
- No room conflict across cohorts at the same time.

Generated sessions use the same period and room structure, and generation rejects room conflicts before creating records.

## How To Generate Sessions

Open the independent cohort sessions page:

`/admin/cohorts/{cohort}/sessions`

Choose:

- Generation mode.
- Start date / end date or total sessions count.
- Study days.
- One or two daily slots.
- Period type for each slot.
- Room for each slot.

Review the preview before syncing. Existing sessions are not replaced unless the safe replacement option is enabled.

## How To Add A Manual Session

From the same page, click "Add session".

The form requires:

- Date.
- Period.
- Start/end time.
- Room.
- Optional instructor.
- Optional online meeting URL.

Locked sessions or sessions with attendance records are protected from unsafe edits.

## Tests Added/Updated

Coverage now includes:

- Required period and room validation.
- Room conflict detection.
- Schedule generation with period and room.
- Locale-aware period labels.
- Scheduling translation key parity for AR/FR.
- Admin room creation and permission checks.