package kmux

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

// MatchIPGlob match ip to glob pattern, ex. * 192.168.* 192.* 192.168.51.*2*
func MatchIPGlob(ip, pattern string) bool {
	parts := strings.Split(pattern, ".")
	seg := strings.Split(ip, ".")
	for i, part := range parts {

		// normalize pattern to 3 digits
		switch len(part) {
		case 1:
			if part == "*" {
				part = "***"
			} else {
				part = "00" + part
			}
		case 2:
			if strings.HasPrefix(part, "*") {
				part = "*" + part
			} else if strings.HasSuffix(part, "*") {
				part = part + "*"
			} else {
				part = "0" + part
			}
		}

		// normalize ip to 3 digits
		switch len(seg[i]) {
		case 1:
			seg[i] = "00" + seg[i]
		case 2:
			seg[i] = "0" + seg[i]
		}

		for j := range part {
			if string(part[j]) == "*" {
				continue
			}
			if part[j] != seg[i][j] {
				return false
			}
		}
	}
	return true
}

// GetIP gets the real ip (could still be tricked by proxy)
func GetIP(r *http.Request) string {
	ip := r.Header.Get("X-Real-Ip")
	if ip == "" {
		ips := r.Header.Get("X-Forwarded-For")
		ipArr := strings.Split(ips, ",")
		ip = strings.Trim(ipArr[len(ipArr)-1], " ")
	}
	if ip == "" {
		var err error
		ip, _, err = net.SplitHostPort(r.RemoteAddr)
		if err != nil {
			ip = r.RemoteAddr
		}
	}
	return ip
}