package geodb

import (
	"net"
	"net/http"
	"strings"
)

// Utilities function
func GetRequesterIP(r *http.Request) string {
	ip := r.Header.Get("X-Forwarded-For")
	if ip == "" {
		ip = r.Header.Get("X-Real-IP")
		if ip == "" {
			ip = strings.Split(r.RemoteAddr, ":")[0]
		}
	}
	return ip
}

// Match the IP address with a wildcard string
func MatchIpWildcard(ipAddress, wildcard string) bool {
	// Split IP address and wildcard into octets
	ipOctets := strings.Split(ipAddress, ".")
	wildcardOctets := strings.Split(wildcard, ".")

	// Check that both have 4 octets
	if len(ipOctets) != 4 || len(wildcardOctets) != 4 {
		return false
	}

	// Check each octet to see if it matches the wildcard or is an exact match
	for i := 0; i < 4; i++ {
		if wildcardOctets[i] == "*" {
			continue
		}
		if ipOctets[i] != wildcardOctets[i] {
			return false
		}
	}

	return true
}

// Match ip address with CIDR
func MatchIpCIDR(ip string, cidr string) bool {
	// parse the CIDR string
	_, cidrnet, err := net.ParseCIDR(cidr)
	if err != nil {
		return false
	}

	// parse the IP address
	ipAddr := net.ParseIP(ip)

	// check if the IP address is within the CIDR range
	return cidrnet.Contains(ipAddr)
}

// Check if a ip is private IP range
func IsPrivateIP(ipStr string) bool {
	ip := net.ParseIP(ipStr)
	if ip == nil {
		return false
	}
	return ip.IsPrivate()
}

// Check if an Ip string is ipv6
func IsIPv6(ipStr string) bool {
	ip := net.ParseIP(ipStr)
	if ip == nil {
		return false
	}

	return ip.To4() == nil && ip.To16() != nil
}