<fixed>fixed bugs that ipinfo db using different symbol for country iso.

pkg/geoip/geoip.go

@@ -24,10 +24,11 @@ var (
 )
 
 type IPInfo struct {
-	Country       string `maxminddb:"country"`
-	CountryName   string `maxminddb:"country_name"`
-	Continent     string `maxminddb:"continent"`
-	ContinentName string `maxminddb:"continent_name"`
+	// 对应数据库里的 "country_code" 字段 (例如 "CN")
+	CountryCode string `maxminddb:"country_code"`
+
+	// 对应数据库里的 "continent_code" 字段 (例如 "AS")
+	ContinentCode string `maxminddb:"continent_code"`
 }
 
 func Lookup(ip net.IP) (string, error) {
@@ -42,10 +43,15 @@ func Lookup(ip net.IP) (string, error) {
 		return "", err
 	}
 
-	if record.Country != "" {
-		return strings.ToLower(record.Country), nil
-	} else if record.Continent != "" {
-		return strings.ToLower(record.Continent), nil
+	// 1. 优先返回 CountryCode (如 "cn")
+	if record.CountryCode != "" {
+		// 前端依然需要小写才能匹配 flags/cn.svg
+		return strings.ToLower(record.CountryCode), nil
+	}
+
+	// 2. 其次返回 ContinentCode
+	if record.ContinentCode != "" {
+		return strings.ToLower(record.ContinentCode), nil
 	}
 
 	return "", errors.New("IP not found")