package validation

import (
	"fmt"
	"net"
	"strings"

	k8svalidation "k8s.io/apimachinery/pkg/util/validation"
)

// ValidateDomain tests that the argument is a valid domain.
func ValidateDomain(domain string) []string {
	if strings.TrimSpace(domain) == "" {
		return nil
	}
	var errs []string
	if strings.Contains(domain, "*") {
		errs = k8svalidation.IsWildcardDNS1123Subdomain(domain)
	} else {
		errs = k8svalidation.IsDNS1123Subdomain(domain)
	}
	return errs
}

// SplitEndpointAddress split URL to domain or IP
func SplitEndpointAddress(resourceAddress string) (address string) {
	if strings.HasPrefix(resourceAddress, "https://") {
		resourceAddress = strings.Split(resourceAddress, "https://")[1]
	}
	if strings.HasPrefix(resourceAddress, "http://") {
		resourceAddress = strings.Split(resourceAddress, "http://")[1]
	}

	if strings.Contains(resourceAddress, ":") {
		sp := strings.Split(resourceAddress, ":")
		address = sp[0]
	} else {
		address = resourceAddress
	}
	return address
}

// ValidateEndpointIP tests that the argument is a valid IP address.
func ValidateEndpointIP(ipAddress string) []string {
	// We disallow some IPs as endpoints or external-ips.  Specifically,
	// unspecified and loopback addresses are nonsensical and link-local
	// addresses tend to be used for node-centric purposes (e.g. metadata
	// service).
	err := []string{}
	ip := net.ParseIP(ipAddress)
	if ip == nil {
		err = append(err, fmt.Sprintf("%s must be a valid IP address", ipAddress))
		return err
	}
	if ip.IsUnspecified() {
		err = append(err, fmt.Sprintf("%s may not be unspecified (0.0.0.0)", ipAddress))
	}
	if ip.IsLoopback() {
		err = append(err, fmt.Sprintf("%s may not be in the loopback range (127.0.0.0/8)", ipAddress))
	}
	if ip.IsLinkLocalUnicast() {
		err = append(err, fmt.Sprintf("%s may not be in the link-local range (169.254.0.0/16)", ipAddress))
	}
	if ip.IsLinkLocalMulticast() {
		err = append(err, fmt.Sprintf("%s may not be in the link-local multicast range (224.0.0.0/24)", ipAddress))
	}
	return err
}

// IsDomainNotIP check address is domain but not is ip
func IsDomainNotIP(address string) bool {
	if address == "1.1.1.1" {
		return true
	}
	if errs := ValidateEndpointIP(address); len(errs) > 0 {
		if strings.Contains(errs[0], "must be a valid IP address") {
			return true
		}
	}
	return false
}