refactor(scheduling): batch queries and DRY retention filter

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/handlers/scheduling/default-hours.go

@@ -92,17 +92,33 @@ func UpdateDefaultHours(w http.ResponseWriter, r *http.Request) {
 	}
 	defer tx.Rollback(r.Context())
 
-	for _, h := range hours {
+	weekdays := make([]int, len(hours))
-		_, err := tx.Exec(r.Context(), `
+	startTimes := make([]string, len(hours))
-			UPDATE working_hours
+	endTimes := make([]string, len(hours))
-			SET start_time=$1,end_time=$2,is_open=$3
+	isOpenFlags := make([]bool, len(hours))
-			WHERE weekday=$4
+	for i, h := range hours {
-		`, h.StartTime, h.EndTime, h.IsOpen, h.Weekday)
+		weekdays[i] = h.Weekday
-		if err != nil {
+		startTimes[i] = h.StartTime
+		endTimes[i] = h.EndTime
+		isOpenFlags[i] = h.IsOpen
+	}
+
+	if _, err := tx.Exec(r.Context(), `
+		UPDATE working_hours AS wh
+		SET start_time = v.start_time,
+		    end_time = v.end_time,
+		    is_open = v.is_open
+		FROM (
+			SELECT unnest($1::smallint[]) AS weekday,
+			       unnest($2::time[]) AS start_time,
+			       unnest($3::time[]) AS end_time,
+			       unnest($4::boolean[]) AS is_open
+		) v
+		WHERE wh.weekday = v.weekday
+	`, weekdays, startTimes, endTimes, isOpenFlags); err != nil {
 		http.Error(w, "failed to update default hours", http.StatusInternalServerError)
 		return
 	}
-	}
 
 	if err := tx.Commit(r.Context()); err != nil {
 		http.Error(w, "failed to commit", http.StatusInternalServerError)

backend/handlers/scheduling/exceptional-hours.go

@@ -218,16 +218,13 @@ func CreateExceptionalGroup(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Insert applications
-	for _, weekStart := range parsedWeeks {
+	if _, err := tx.Exec(r.Context(), `
-		_, err := tx.Exec(r.Context(), `
 		INSERT INTO exceptional_group_applications (group_id, week_start)
-			VALUES ($1, $2)
+		SELECT $1, unnest($2::date[])
-		`, g.ID, weekStart)
+	`, g.ID, parsedWeeks); err != nil {
-		if err != nil {
+		http.Error(w, "failed to insert applications", http.StatusInternalServerError)
-			http.Error(w, "failed to insert application", http.StatusInternalServerError)
 		return
 	}
-	}
 
 	if err := tx.Commit(r.Context()); err != nil {
 		http.Error(w, "failed to commit transaction", http.StatusInternalServerError)
@@ -328,16 +325,13 @@ func UpdateExceptionalApplications(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Insert new applications
-	for _, weekStart := range parsedWeeks {
+	if _, err := tx.Exec(r.Context(), `
-		_, err := tx.Exec(r.Context(), `
 		INSERT INTO exceptional_group_applications (group_id, week_start)
-			VALUES ($1, $2)
+		SELECT $1, unnest($2::date[])
-		`, req.GroupID, weekStart)
+	`, req.GroupID, parsedWeeks); err != nil {
-		if err != nil {
+		http.Error(w, "failed to insert applications", http.StatusInternalServerError)
-			http.Error(w, "failed to insert application", http.StatusInternalServerError)
 		return
 	}
-	}
 
 	if err := tx.Commit(r.Context()); err != nil {
 		http.Error(w, "failed to commit transaction", http.StatusInternalServerError)

backend/handlers/scheduling/time-blockers.go

@@ -197,12 +197,11 @@ func DeleteTimeBlocker(w http.ResponseWriter, r *http.Request) {
 // Returns blockers for the given date range, expanded for recurring blockers
 // Used by GetAvailableHours to subtract blocked time from available slots
 func GetTimeBlockersInRange(ctx context.Context, start, end time.Time) ([]TimeBlocker, error) {
-	// Get one-off blockers in range
 	rows, err := db.Conn.Query(ctx, `
 		SELECT id, start_time, duration_minutes, description, cron_expression, created_at, created_by
 		FROM time_blockers
-		WHERE cron_expression IS NULL
+		WHERE (cron_expression IS NULL AND start_time >= $1 AND start_time <= $2)
-		AND start_time >= $1 AND start_time <= $2
+		   OR (cron_expression IS NOT NULL)
 		ORDER BY start_time
 	`, start, end)
 	if err != nil {
@@ -216,30 +215,15 @@ func GetTimeBlockersInRange(ctx context.Context, start, end time.Time) ([]TimeBl
 		if err := rows.Scan(&b.ID, &b.StartTime, &b.DurationMinutes, &b.Description, &b.CronExpression, &b.CreatedAt, &b.CreatedBy); err != nil {
 			return nil, err
 		}
-		blockers = append(blockers, b)
+		if b.CronExpression != nil {
-	}
-	rows.Close()
-
-	// Get ALL recurring blockers and expand them
-	recurringRows, err := db.Conn.Query(ctx, `
-		SELECT id, start_time, duration_minutes, description, cron_expression, created_at, created_by
-		FROM time_blockers
-		WHERE cron_expression IS NOT NULL
-	`)
-	if err != nil {
-		return nil, err
-	}
-	defer recurringRows.Close()
-
-	for recurringRows.Next() {
-		var b TimeBlocker
-		if err := recurringRows.Scan(&b.ID, &b.StartTime, &b.DurationMinutes, &b.Description, &b.CronExpression, &b.CreatedAt, &b.CreatedBy); err != nil {
-			return nil, err
-		}
-
-		// Expand recurring blocker to occurrences within range
 			occurrences := expandCronOccurrences(b, start, end)
 			blockers = append(blockers, occurrences...)
+		} else {
+			blockers = append(blockers, b)
+		}
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
 	}
 
 	return blockers, nil
@@ -459,6 +443,14 @@ func CleanupExpiredLoyaltyRedemptions(ctx context.Context) error {
 //   - Anonymized users: 7 years from payment creation AND 1 year since anonymization
 //
 // The function is idempotent — running it twice produces the same result.
+
+const retentionFilter = `AND (
+    b.user_id IS NULL
+    OR u.id IS NULL
+    OR NOT (u.account_role = 'guest' AND (u.email LIKE 'anon-%@anon.invalid' OR u.email LIKE 'deleted+%@deleted.invalid'))
+    OR u.updated_at < NOW() - INTERVAL '1 year'
+)`
+
 func CleanupExpiredFinancialRecords(ctx context.Context) error {
 	tx, err := db.Conn.Begin(ctx)
 	if err != nil {
@@ -486,12 +478,7 @@ func CleanupExpiredFinancialRecords(ctx context.Context) error {
 		LEFT JOIN bookings b ON p.booking_id = b.id
 		LEFT JOIN users u ON b.user_id = u.id
 		WHERE p.created_at < NOW() - INTERVAL '7 years'
-		  AND (
+		` + retentionFilter + `
-			  b.user_id IS NULL
-			  OR u.id IS NULL
-			  OR NOT (u.account_role = 'guest' AND (u.email LIKE 'anon-%@anon.invalid' OR u.email LIKE 'deleted+%@deleted.invalid'))
-			  OR u.updated_at < NOW() - INTERVAL '1 year'
-		  )
 		GROUP BY DATE_TRUNC('month', p.created_at)::date
 		ON CONFLICT (month) DO UPDATE SET
 			total_payments     = financial_aggregates.total_payments + EXCLUDED.total_payments,
@@ -521,12 +508,7 @@ func CleanupExpiredFinancialRecords(ctx context.Context) error {
 		LEFT JOIN bookings b ON p.booking_id = b.id
 		LEFT JOIN users u ON b.user_id = u.id
 		WHERE p.created_at < NOW() - INTERVAL '7 years'
-		  AND (
+		` + retentionFilter + `
-			  b.user_id IS NULL
-			  OR u.id IS NULL
-			  OR NOT (u.account_role = 'guest' AND (u.email LIKE 'anon-%@anon.invalid' OR u.email LIKE 'deleted+%@deleted.invalid'))
-			  OR u.updated_at < NOW() - INTERVAL '1 year'
-		  )
 		GROUP BY DATE_TRUNC('month', r.created_at)::date
 		ON CONFLICT (month) DO UPDATE SET
 			total_refunds = financial_aggregates.total_refunds + EXCLUDED.total_refunds
@@ -541,12 +523,7 @@ func CleanupExpiredFinancialRecords(ctx context.Context) error {
 		LEFT JOIN users u ON b.user_id = u.id
 		WHERE p.booking_id = b.id
 		  AND p.created_at < NOW() - INTERVAL '7 years'
-		  AND (
+		` + retentionFilter + `
-			  b.user_id IS NULL
-			  OR u.id IS NULL
-			  OR NOT (u.account_role = 'guest' AND (u.email LIKE 'anon-%@anon.invalid' OR u.email LIKE 'deleted+%@deleted.invalid'))
-			  OR u.updated_at < NOW() - INTERVAL '1 year'
-		  )
 	`)
 	if err != nil {
 		return fmt.Errorf("failed to delete expired payments: %w", err)
@@ -559,12 +536,7 @@ func CleanupExpiredFinancialRecords(ctx context.Context) error {
 		LEFT JOIN users u ON b.user_id = u.id
 		WHERE r.payment_id = p.id
 		  AND p.created_at < NOW() - INTERVAL '7 years'
-		  AND (
+		` + retentionFilter + `
-			  b.user_id IS NULL
-			  OR u.id IS NULL
-			  OR NOT (u.account_role = 'guest' AND (u.email LIKE 'anon-%@anon.invalid' OR u.email LIKE 'deleted+%@deleted.invalid'))
-			  OR u.updated_at < NOW() - INTERVAL '1 year'
-		  )
 	`)
 	if err != nil {
 		return fmt.Errorf("failed to delete expired refunds: %w", err)
@@ -867,10 +839,10 @@ func CleanupIdleAccounts(ctx context.Context) error {
 			return fmt.Errorf("failed to batch zero account balances: %w", err)
 		}
 
-		for _, id := range ids {
+		if _, err = tx.Exec(ctx, `
-			if _, err = tx.Exec(ctx, "SELECT anonymize_user($1)", id); err != nil {
+			SELECT anonymize_user(unnest($1::text[]))
-				return fmt.Errorf("failed to anonymize idle account %s: %w", id, err)
+		`, ids); err != nil {
-			}
+			return fmt.Errorf("failed to anonymize idle accounts: %w", err)
 		}
 	}
 
@@ -899,10 +871,10 @@ func CleanupIdleAccounts(ctx context.Context) error {
 	}
 	rowsNoBalance.Close()
 
-	for _, id := range accountsNoBalance {
+	if _, err = tx.Exec(ctx, `
-		if _, err = tx.Exec(ctx, "SELECT anonymize_user($1)", id); err != nil {
+		SELECT anonymize_user(unnest($1::text[]))
-			return fmt.Errorf("failed to anonymize idle account %s: %w", id, err)
+	`, accountsNoBalance); err != nil {
-		}
+		return fmt.Errorf("failed to anonymize idle accounts: %w", err)
 	}
 
 	return tx.Commit(ctx)