Add support for parsing IPs by version (IPv4 and IPv6) with validation logic

parser/parser.go

@@ -11,14 +11,25 @@ import (
 type Parser interface {
 	// Parse reads the body and returns a slice of IP addresses.
 	Parse(body io.Reader, validator IPValidator, limit uint) (IPs, error)
+
+	ParseIPsByVersion(body io.Reader, validator IPValidator, limit uint) (ipV4 IPs, ipV6 IPs, err error)
 }
 
 // IPValidator interface defines the contract for validating IP addresses.
 type IPValidator interface {
 	// IsValid checks if the given IP address is valid.
 	IsValid(ip string) bool
+
+	IsValidAndReturnVersion(ip string) (bool, IPVersion)
 }
 
+type IPVersion int
+
+const (
+	IPVersion4 IPVersion = iota
+	IPVersion6
+)
+
 // IPs is a slice of IP addresses.
 type IPs []string
 
@@ -50,6 +61,48 @@ func (v *DefaultIPValidator) IsValid(value string) bool {
 	return false
 }
 
+// IsValidAndReturnVersion checks if the given IP address is valid and returns the IP version.
+// It returns true if the IP address is not a loopback address and the IP version is either IPv4 or IPv6.
+func (v *DefaultIPValidator) IsValidAndReturnVersion(value string) (bool, IPVersion) {
+	if value == "" {
+		return false, IPVersion4
+	}
+
+	if ip := net.ParseIP(value); ip != nil {
+		if ip.IsLoopback() {
+			return false, IPVersion4
+		}
+
+		if ip.To4() != nil {
+			return true, IPVersion4
+		}
+
+		if ip.To16() != nil {
+			return true, IPVersion6
+		}
+
+		return false, IPVersion4
+	}
+
+	if ip, _, err := net.ParseCIDR(value); err == nil {
+		if ip.IsLoopback() {
+			return false, IPVersion4
+		}
+
+		if ip.To4() != nil {
+			return true, IPVersion4
+		}
+
+		if ip.To16() != nil {
+			return true, IPVersion6
+		}
+
+		return false, IPVersion4
+	}
+
+	return false, IPVersion4
+}
+
 // IPRangeValidator implements IPValidator interface.
 // It validates IP ranges by parsing them using net.ParseIP and checking if the start and end IPs are in the same network.
 type IPRangeValidator struct{}
@@ -89,3 +142,43 @@ func (v *IPRangeValidator) IsValid(value string) bool {
 		return false
 	}
 }
+
+func (v *IPRangeValidator) IsValidAndReturnVersion(value string) (bool, IPVersion) {
+	if value == "" {
+		return false, IPVersion4
+	}
+
+	parts := strings.Split(value, "-")
+	if len(parts) != 2 {
+		return false, IPVersion4
+	}
+
+	start := net.ParseIP(strings.TrimSpace(parts[0]))
+	end := net.ParseIP(strings.TrimSpace(parts[1]))
+	if start == nil || end == nil {
+		return false, IPVersion4
+	}
+
+	start4 := start.To4()
+	end4 := end.To4()
+
+	switch {
+	case start4 != nil && end4 != nil:
+		if bytes.Compare(start4, end4) <= 0 {
+			return true, IPVersion4
+		}
+		return false, IPVersion4
+	case start4 == nil && end4 == nil:
+		start16 := start.To16()
+		end16 := end.To16()
+		if start16 == nil || end16 == nil {
+			return false, IPVersion4
+		}
+		if bytes.Compare(start16, end16) <= 0 {
+			return true, IPVersion6
+		}
+		return false, IPVersion4
+	default:
+		return false, IPVersion4
+	}
+}