完善初始化更新

sproutgate-backend/internal/clientgeo/clientgeo.go

@@ -0,0 +1,70 @@
+package clientgeo
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const DefaultLookupURL = "https://cf-ip-geo.smyhub.com/api"
+
+type apiPayload struct {
+	Geo *struct {
+		CountryName string `json:"countryName"`
+		RegionName  string `json:"regionName"`
+		CityName    string `json:"cityName"`
+	} `json:"geo"`
+}
+
+func FormatDisplay(countryName, regionName, cityName string) string {
+	parts := make([]string, 0, 3)
+	for _, s := range []string{countryName, regionName, cityName} {
+		s = strings.TrimSpace(s)
+		if s != "" {
+			parts = append(parts, s)
+		}
+	}
+	return strings.Join(parts, " ")
+}
+
+// FetchDisplayLocation 使用 cf-ip-geo 的 ?ip= 查询展示用位置（服务端调用，避免浏览器 CORS）。
+func FetchDisplayLocation(ctx context.Context, lookupURL, ip string) (string, error) {
+	ip = strings.TrimSpace(ip)
+	if ip == "" {
+		return "", nil
+	}
+	base := strings.TrimSuffix(strings.TrimSpace(lookupURL), "/")
+	u, err := url.Parse(base)
+	if err != nil || u.Scheme == "" || u.Host == "" {
+		return "", fmt.Errorf("invalid lookup URL")
+	}
+	q := u.Query()
+	q.Set("ip", ip)
+	u.RawQuery = q.Encode()
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+	if err != nil {
+		return "", err
+	}
+	client := &http.Client{Timeout: 6 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("geo status %d", resp.StatusCode)
+	}
+	var payload apiPayload
+	if err := json.NewDecoder(resp.Body).Decode(&payload); err != nil {
+		return "", err
+	}
+	if payload.Geo == nil {
+		return "", nil
+	}
+	return FormatDisplay(payload.Geo.CountryName, payload.Geo.RegionName, payload.Geo.CityName), nil
+}