Booking — Codebase flow

This page traces API → service → validation for normal booking. Key files:

Overall

API: CreateBookingOrder.
Creates TermBookingOrder + TermBookingOrderLine (status Created).
Validates: valid attendee/term product, org settings, measurement (height/weight) if enabled, double-booking (unless IgnoreDoubleBooking).
Does not create Billing yet.

API: SubmitBookingOrders → BookingService.SubmitBookingAsync.
Accepts only order types Booking and TrialSession.
Creates Billing (financial summary); validates Pay Later eligibility (via BookingHelper).
May arm an auto-cancel timeout if the payment option requires one (PayNow/Deposit/Direct Debit).
Final double-booking check. Status → Submitted. Does not create the Invoice yet.

API: ConfirmBookingOrders → BookingService.ConfirmBookingAsync (or GenerateQuotesAsync/AcceptQuoteAsync).
Creates TermBooking from TermBookingOrder; copies Line/Extra/Discount.
Applies discounts, computes totals (see Discount rule).
Creates TermAttendance per session; triggers billing to generate invoices.
Status → Approved (or Attendance_Approved, or Quote).
Edited booking: confirm builds a shared BookingConfirmationPlan from TermBookingOrderIds before applying real side effects (invariant INV-BOOK-23).

API: DeleteBookingOrdersAsync → BookingService.CancelBookingAsync.
Status → Canceled; reverses invoices via credit note; deactivates TermAttendance (even if some lines previously left Approved).

Type	Where
Capacity	`TermProduct.Capacity`, `TermProgramSetCapacity`; checked at create/submit/confirm.
Double-booking	Attendee × session overlap on date/time; bypass via `IgnoreDoubleBooking`.
Measurement	Height/weight vs course config; admin overrides each rule.
Lock & pending	Locked booking / conflicting pending order → edit blocked.
Discount eligibility	`DiscountEligibilityService` + `BookingHelper.ApplyDiscount`.