add domain whois/dns support, refactor codebase

internal/db/types.go

@@ -0,0 +1,24 @@
+package db
+
+import "errors"
+
+// Constants for database names and paths
+const (
+	CityDBName  = "GeoLite2-City"
+	ASNDBName   = "GeoLite2-ASN"
+	DBExtension = ".mmdb"
+	CityDBPath  = CityDBName + DBExtension
+	ASNDBPath   = ASNDBName + DBExtension
+)
+
+// Error messages
+var (
+	ErrDatabaseOpen   = errors.New("failed to open database")
+	ErrDownloadFailed = errors.New("failed to download database")
+)
+
+// ASNRecord represents a record in the ASN database
+type ASNRecord struct {
+	AutonomousSystemNumber       uint   `maxminddb:"autonomous_system_number"`
+	AutonomousSystemOrganization string `maxminddb:"autonomous_system_organization"`
+}