Notifications

RateNet dispatches transactional emails to every party involved in a booking or billing event. The notification system is event-driven and multi-recipient: a single lifecycle event (e.g. booking confirmed) can send different, contextually appropriate emails to the guest, the client agency, the hotel, the tenant operator, and a system-level superadmin mailbox — all from one trigger.

Architecture overview

Domain event (e.g. booking confirmed)
        │
        ▼
  BookingNotifier / StatementNotifier
        │
        ├─ resolveRecipients()  ← who gets notified for this event?
        │
        ├─ subject()            ← per-recipient subject line
        │
        ├─ templateName()       ← {event}_{recipientType}
        │
        └─ EmailService.SendTemplated()  ← async SMTP dispatch

Notifications are fire-and-forget: they are sent asynchronously and never block the booking or billing flow. Errors are logged but not propagated.

Recipient types

3-tier email routing

Every party has a master email (required fallback) and optional domain-specific overrides that let you route different notification types to different inboxes.

System level (.env)

[email protected]

This is the superadmin inbox. It receives a copy of every event with full financial context (tenant, client, hotel, sell, cost, margin). It is deliberately not stored in the database.

Tenant level

Client level

Hotel level (direct contracts)

The EmailForDomain(domain string) string method is implemented on Tenant, Client, and SupplierHotel. It returns the domain-specific email if set, falling back to the master email.

Booking events

Booked through BookingNotifier, triggered by bookingService.NotifyAllParties().

Subject line patterns

Template naming

Template names follow the pattern {event}_{recipientType}:

booking_confirmed_holder
booking_confirmed_client
booking_confirmed_hotel
booking_confirmed_tenant
booking_confirmed_superadmin
booking_cancelled_holder
booking_cancelled_client
...
deadline_reminder_holder
deadline_reminder_client
deadline_reminder_tenant
deadline_reminder_superadmin

Template data

All booking templates receive a notificationTemplateData struct with:

Statement events

Handled by StatementNotifier, triggered by statementService.Notify().

AR = Accounts Receivable (client owes money). AP = Accounts Payable (we owe the hotel/supplier).

Subject line patterns

Template naming

statement_created_tenant
statement_created_superadmin
statement_sent_tenant
statement_sent_client
statement_sent_superadmin
statement_paid_tenant
statement_paid_superadmin
statement_voided_tenant
statement_voided_superadmin

Deadline reminders

Deadline reminders run as a background task on a configurable schedule per tenant.

Tenant configuration:

The DeadlineReminder service queries for confirmed, non-nonrefundable bookings whose deadline falls within a ±12-hour window of each configured tier. Reminders are guaranteed idempotent — each (booking_id, tier_days) pair is recorded in deadline_reminder_sents and will never be sent twice.

Email service

EmailService handles SMTP dispatch with an in-memory audit log.

Configuration (.env):

SMTP_HOST=smtp.example.com
SMTP_PORT=587
[email protected]
SMTP_PASSWORD=secret
[email protected]
SMTP_FROM_NAME=RateNet

Key behaviours:

• Sending is always asynchronous (goroutine per email)
• 30-second timeout per send attempt
• In-memory audit log (last 10,000 records) accessible via emailService.GetAuditLog()
• Failed emails accessible via emailService.GetFailedEmails()
• If SMTP_HOST is not set, SendTemplated() returns an error immediately (no panic)

Adding a new event

1. Define a new constant in booking_notifier.go or statement_notifier.go
2. Add recipient logic in resolveRecipients()
3. Add subject lines in subject()
4. Add template(s) in email.go following the {event}_{recipientType} naming convention
5. Call NotifyBookingEvent() or NotifyStatementEvent() from the service layer