package database

// NotificationMigrations creates the one table Phase 9d needs:
//
//	notification_log — one row per (event, lead_days, audience, channel)
//	that the cron scanner has already attempted. The UNIQUE constraint
//	makes the cron idempotent — running it twice on the same day does
//	not re-send.
//
// channel ∈ {'matrix', 'email'} — set by the dispatcher.
// audience ∈ {'parents', 'students'}.
// status ∈ {'sent', 'failed', 'skipped'} — 'skipped' when the upstream
// service URL isn't configured, so we know not to count it as failure.
func NotificationMigrations() []string {
	return []string{
		`CREATE TABLE IF NOT EXISTS notification_log (
			id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
			event_id UUID NOT NULL REFERENCES cal_school_event(id) ON DELETE CASCADE,
			lead_days INT NOT NULL,
			audience VARCHAR(20) NOT NULL CHECK (audience IN ('parents','students')),
			channel VARCHAR(20) NOT NULL CHECK (channel IN ('matrix','email')),
			status VARCHAR(20) NOT NULL CHECK (status IN ('sent','failed','skipped')),
			error_message TEXT,
			run_date DATE NOT NULL,
			created_at TIMESTAMPTZ DEFAULT NOW(),
			UNIQUE(event_id, lead_days, audience, channel)
		)`,
		`CREATE INDEX IF NOT EXISTS idx_notification_log_event ON notification_log(event_id)`,
		`CREATE INDEX IF NOT EXISTS idx_notification_log_run_date ON notification_log(run_date)`,
	}
}