package classes

import (
	"context"
	"fmt"

	"gorm.io/gorm"
)

// TouchLastSeen stamps users.last_seen with the current time, at most once
// per five minutes per user: it is one UPDATE that matches the row only when
// last_seen is NULL or older than five minutes, so a busy client costs one
// write per window. It does not touch updated_at, and it applies to a
// deactivated user too. Login and token refresh call it and ignore its
// error apart from logging it: authentication never depends on this write.
func TouchLastSeen(ctx context.Context, db *gorm.DB, userID uint) error {
	if db == nil {
		return fmt.Errorf("golem15.user: gorm handle is missing")
	}
	if userID == 0 {
		return nil
	}
	return fresh(ctx, db).Exec(
		`UPDATE users SET last_seen = NOW() WHERE id = ? AND (last_seen IS NULL OR last_seen < NOW() - INTERVAL '5 minutes')`,
		userID,
	).Error
}