# Feature: Offerings

## Overview
An offering is anything a student can register for: a private-lesson type (30 or 60 minutes, single or weekly) or a group class. Offerings carry pricing, billing mode, and the intake questions a registrant must answer. They are the catalog the booking calendar and group-class pages are built from.

## Data Model — `{prefix}us_offerings`

| Column             | Type             | Notes                                                       |
|--------------------|------------------|-------------------------------------------------------------|
| `id`               | BIGINT UNSIGNED  | Primary key                                                 |
| `instructor_id`    | BIGINT UNSIGNED  | WordPress user ID of the owning instructor                  |
| `kind`             | VARCHAR(20)      | `private_lesson` or `group_class`                           |
| `title`            | VARCHAR(191)     | Display name                                                |
| `description`      | TEXT             | Optional longer description                                 |
| `duration_minutes` | SMALLINT         | Private lessons only (e.g. 30, 60); NULL for group classes  |
| `price`            | DECIMAL(10,2)    | Price in dollars                                            |
| `currency`         | VARCHAR(3)       | ISO 4217, e.g. `CAD`                                        |
| `billing_mode`     | VARCHAR(20)      | `one_time`, `full_term`, `weekly`, or `monthly` (see Billing Mode below) |
| `allow_weekly`     | TINYINT(1)       | Private only — may be reserved weekly for the term          |
| `capacity`         | SMALLINT         | Group only — max enrolments; NULL for private               |
| `term_start`       | DATE             | Group / term offerings — first day; NULL otherwise          |
| `term_end`         | DATE             | Group / term offerings — last day; NULL otherwise           |
| `class_time`       | TIME             | Group only — time of day each session starts; NULL otherwise |
| `enrollment_deadline` | DATE          | Group only — last day students may enrol; NULL defaults to `term_start` (the first class day) |
| `withdrawal_deadline` | DATE          | Group only — last day a student may withdraw themselves; NULL keeps self-withdrawal open indefinitely |
| `schedule_note`    | VARCHAR(191)     | Group only — human-readable schedule, e.g. "Tuesdays 4:00pm"|
| `cancellation_cutoff_hours` | SMALLINT UNSIGNED | Optional per-offering cancellation cutoff in hours; NULL inherits the studio default (see `cancellation-cutoff.md`) |
| `access_mode`      | VARCHAR(20)      | `public` (listed in the catalog) or `invite_only` (group classes hidden from the catalog — see `group-classes.md`) |
| `is_active`        | TINYINT(1)       | 0 = hidden from registration, 1 = bookable                  |
| `created_at`       | DATETIME         | Insertion time                                              |

## Billing Mode
- `one_time` — charged once at booking (a single private lesson).
- `full_term` — charged in full upfront at registration (a weekly private reservation or a year-long group class). See `payments.md`.
- `weekly` — **not** charged at registration; a pending payment for one lesson's fee is generated **24 hours before each lesson** by the daily billing scan.
- `monthly` — **not** charged at registration; on the **1st of each month** a single pending payment is generated for every lesson that falls in that month (4 lessons ⇒ 4 × fee).

`weekly` and `monthly` are *scheduled* billing (`Offering::isScheduledBilling()`): the
booking/enrolment succeeds with no payment step, and payments are created later by the
daily `us_generate_due_payments` cron scan. See `scheduled-billing.md` and `payments.md`.

## Term Dates
Group classes carry a term: `term_start` is the date of the first class and
`term_end` the last. The add-offering form takes a start date plus a sessions
control — **one-off** (the term ends the day it starts) or **weekly for N
sessions** (`term_end = term_start + (N−1) weeks`, computed by
`Offering::weeklyTermEnd()`). Dates are validated by `Offering::normalizeDate()`
(strict `Y-m-d`); an invalid start date leaves both term columns NULL. The
student-facing class card shows the date (one-off) or the date range with the
weekly session count.

## Class Time and Sessions
A group class also carries `class_time` — the time of day each session starts —
validated by `Offering::normalizeTime()` (strict `H:i`/`H:i:s`; garbage leaves it
NULL). `class_time` + `term_start`/`term_end` + `duration_minutes` together define
the concrete session windows: `Offering::sessionWindows()` returns one
`{start, end}` per session (weekly across the term, or a single window for a
one-off), and returns an empty list unless date, time, and a positive duration are
all set. These windows drive availability reconciliation (see **Instructor
assignment** below and `group-classes.md`).

## Enrolment deadline
A group class carries an optional `enrollment_deadline` the instructor sets on the
offering form (blank leaves it NULL). `Offering::effectiveEnrollmentDeadline()`
resolves it to the stored date, or to `term_start` (the first class day) when unset,
so a class with no explicit deadline still closes to new enrolments once the first
class arrives. `Offering::isEnrollmentOpen($today)` compares a `Y-m-d` "today"
against that effective deadline (inclusive — the deadline day is still open). The
enrolment endpoint enforces it (`403 enrollment_closed`) and the front-end
group-class list mirrors the same rule; see `group-classes.md`.

## Withdrawal deadline
A group class also carries an optional `withdrawal_deadline` — the last day a
student may withdraw *themselves* from the class. Unlike the enrolment deadline it
has **no implicit default**: `Offering::isWithdrawalOpen($today)` treats an unset
(NULL) deadline as always open, so a class only closes to self-withdrawal once the
instructor sets a date and it passes (comparison is inclusive — the deadline day is
still open). A withdrawal made while open frees the seat and voids any still-pending
payment but **never issues an account credit** (credits are reserved for cancelled
lessons; see `credits.md`). Once the deadline passes the student must contact the
studio, and an admin withdraws them by hand from the student detail page — the admin
path is never subject to the deadline. The student endpoint enforces it
(`403 withdrawal_closed`) and the front-end group-class list mirrors the rule; see
`group-classes.md`.

## Instructor assignment
Every offering has an owning `instructor_id`. A studio admin
(`manage_instructors`) sees an **Instructor** picker on the offering form and may
assign a group class to any instructor; a plain instructor never sees the picker
and always owns the classes they create (the posted value is ignored for them, and
updates never reassign the owner otherwise). When a group class is saved with an
assigned instructor and a full schedule, `Offering\ClassSlotReconciler` clears that
instructor's **open** availability slots overlapping each session so students can't
book them, and reports any **already-booked** lesson that clashes as a conflict for
the studio to resolve by hand (a booked lesson is never deleted). The result is
surfaced as an admin notice after saving.

## Admin Interface
Studio admin and instructors manage offerings under **Offerings** in wp-admin.
- Studio admin (`manage_offerings`) manages offerings for any instructor.
- Instructor (`manage_offerings`) manages only their own.
- Each offering's intake questions are edited from the offering screen (see `registration-questions.md`).
- The offerings list shows each offering's ID (needed for `[us_group_classes offering="…"]`) and its term dates.
- **Edit** on a row reloads the page (`?usc_edit=<id>`) with the form prefilled; saving posts `usc_action=update`. Owner and currency are always preserved on update, so a form submission can never reassign an offering. Non-admin instructors can only load and update their own offerings.
- The form includes a **description** textarea and an **Active — open for registration** checkbox (unchecking hides the offering from students without deleting it — the admin-UI counterpart of the REST `is_active` flag).

## REST API
| Method   | Endpoint                                    | Permission                       |
|----------|---------------------------------------------|----------------------------------|
| `GET`    | `/wp-json/us-scheduler/v1/offerings`        | `book_lesson` or `manage_offerings` (active offerings only) |
| `POST`   | `/wp-json/us-scheduler/v1/offerings`        | `manage_offerings`               |
| `PATCH`  | `/wp-json/us-scheduler/v1/offerings/{id}`   | `manage_offerings` + owner       |
| `DELETE` | `/wp-json/us-scheduler/v1/offerings/{id}`   | `manage_offerings` + owner       |

`GET` supports query params: `instructor_id`, `kind`.

## Implementation
- Repository: `Unsupervised\Schedular\Offering\OfferingRepository`
- Model: `Unsupervised\Schedular\Offering\Offering` (`normalizeTime`, `sessionWindows`, `effectiveEnrollmentDeadline`, `isEnrollmentOpen`)
- Admin controller: `Unsupervised\Schedular\Offering\OfferingController`
- REST endpoint: `Unsupervised\Schedular\Offering\OfferingEndpoint` (public listing includes `instructor_name`)
- Availability reconciliation: `Unsupervised\Schedular\Offering\ClassSlotReconciler` (uses `Availability\AvailabilityRepository::findOverlapping`)

## Tests
- `tests/Unit/Offering/OfferingControllerTest.php`
- `tests/Unit/Offering/OfferingRepositoryTest.php`
- `tests/Unit/Offering/OfferingTest.php`
- `tests/Unit/Offering/OfferingEndpointTest.php`
- `tests/Unit/Offering/ClassSlotReconcilerTest.php`