past-go/past-go/internal/geo/geo.go

// Package geo 对应 index.php 顶部的腾讯位置服务函数：逆地理编码、IP 定位、球面距离。
package geo

import (
	"encoding/json"
	"fmt"
	"io"
	"math"
	"net/http"
	"net/url"
	"strings"
	"time"

	"past/internal/store"
)

type Client struct {
	Key  string
	http *http.Client
}

func New(key string) *Client {
	return &Client{Key: key, http: &http.Client{Timeout: 5 * time.Second}}
}

func (c *Client) get(u string) map[string]any {
	resp, err := c.http.Get(u)
	if err != nil {
		return nil
	}
	defer resp.Body.Close()
	b, _ := io.ReadAll(resp.Body)
	if len(b) == 0 {
		return nil
	}
	var data map[string]any
	if json.Unmarshal(b, &data) != nil {
		return nil
	}
	return data
}

func statusOK(data map[string]any) bool {
	if data == nil {
		return false
	}
	st, ok := data["status"]
	// PHP 用 === 0 判断：JSON 数字 0 解码为 float 0
	return ok && store.ToFloat(st) == 0 && st != nil
}

func sub(m map[string]any, key string) map[string]any {
	if m == nil {
		return nil
	}
	v, _ := m[key].(map[string]any)
	return v
}

// ReverseGeocode 经纬度（gcj02）→ "省 市 区县"；未配置 key 或失败返回空串。
func (c *Client) ReverseGeocode(lat, lng float64) string {
	if c.Key == "" || lat == 0 || lng == 0 {
		return ""
	}
	u := fmt.Sprintf("https://apis.map.qq.com/ws/geocoder/v1/?location=%s,%s&key=%s&coord_type=5",
		store.ToStr(lat), store.ToStr(lng), url.QueryEscape(c.Key))
	data := c.get(u)
	if !statusOK(data) {
		return ""
	}
	result := sub(data, "result")
	comp := sub(result, "address_component")
	if comp == nil {
		return ""
	}
	var parts []string
	prov, city, dist := store.ToStr(comp["province"]), store.ToStr(comp["city"]), store.ToStr(comp["district"])
	if prov != "" {
		parts = append(parts, prov)
	}
	if city != "" && city != prov {
		parts = append(parts, city)
	}
	if dist != "" {
		parts = append(parts, dist)
	}
	if len(parts) > 0 {
		return strings.Join(parts, " ")
	}
	return store.ToStr(result["address"])
}

// IPGeolocate IP → "市 区县 街道"（不含省份）；失败返回空串。
func (c *Client) IPGeolocate(ip string) string {
	if c.Key == "" || ip == "" || ip == "127.0.0.1" || ip == "::1" {
		return ""
	}
	data := c.get("https://apis.map.qq.com/ws/location/v1/ip?ip=" + url.QueryEscape(ip) + "&key=" + url.QueryEscape(c.Key))
	if !statusOK(data) {
		return ""
	}
	result := sub(data, "result")
	ad := sub(result, "ad_info")
	if ad == nil {
		return ""
	}
	if loc := sub(result, "location"); loc != nil && store.Truthy(loc["lat"]) && store.Truthy(loc["lng"]) {
		geo := c.get(fmt.Sprintf("https://apis.map.qq.com/ws/geocoder/v1/?location=%s,%s&key=%s&coord_type=5",
			store.ToStr(loc["lat"]), store.ToStr(loc["lng"]), url.QueryEscape(c.Key)))
		if statusOK(geo) {
			if comp := sub(sub(geo, "result"), "address_component"); comp != nil {
				var parts []string
				prov, city, dist, street := store.ToStr(comp["province"]), store.ToStr(comp["city"]), store.ToStr(comp["district"]), store.ToStr(comp["street"])
				if city != "" && city != prov {
					parts = append(parts, city)
				}
				if dist != "" {
					parts = append(parts, dist)
				}
				if street != "" {
					parts = append(parts, street)
				}
				if len(parts) > 0 {
					return strings.Join(parts, " ")
				}
			}
		}
	}
	var parts []string
	prov, city, dist := store.ToStr(ad["province"]), store.ToStr(ad["city"]), store.ToStr(ad["district"])
	if city != "" && city != prov {
		parts = append(parts, city)
	}
	if dist != "" {
		parts = append(parts, dist)
	}
	if len(parts) > 0 {
		return strings.Join(parts, " ")
	}
	return store.ToStr(sub(result, "location")["city"])
}

// Haversine 两点球面距离（公里，保留 1 位小数）
func Haversine(lat1, lng1, lat2, lng2 float64) float64 {
	const r = 6371.0
	dLat := (lat2 - lat1) * math.Pi / 180
	dLng := (lng2 - lng1) * math.Pi / 180
	a := math.Sin(dLat/2)*math.Sin(dLat/2) +
		math.Cos(lat1*math.Pi/180)*math.Cos(lat2*math.Pi/180)*math.Sin(dLng/2)*math.Sin(dLng/2)
	c := 2 * math.Atan2(math.Sqrt(a), math.Sqrt(1-a))
	return math.Round(r*c*10) / 10
}