package utils

import (
	"net/http"
	"strings"
)

// 获取真实IP地址
func GetRealIP(r *http.Request) string {
	// 尝试从 X-Real-IP 获取
	if ip := r.Header.Get("X-Real-IP"); ip != "" {
		return ip
	}

	// 尝试从 X-Forwarded-For 获取
	if ip := r.Header.Get("X-Forwarded-For"); ip != "" {
		// X-Forwarded-For 可能包含多个 IP，第一个是真实 IP
		ips := strings.Split(ip, ",")
		if len(ips) > 0 {
			return strings.TrimSpace(ips[0])
		}
	}

	// 尝试从 RemoteAddr 获取
	ip := r.RemoteAddr
	// RemoteAddr 包含端口号，需要去除
	if colonIndex := strings.LastIndex(ip, ":"); colonIndex != -1 {
		ip = ip[:colonIndex]
	}

	// 去除 IPv6 的中括号
	ip = strings.TrimPrefix(ip, "[")
	ip = strings.TrimSuffix(ip, "]")

	return ip
}