Add AMap location and weather header with warm mini program theme

pets-be/internal/environment/amap.go

@@ -0,0 +1,146 @@
+package environment
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"math"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+)
+
+var ErrNotConfigured = errors.New("位置和天气服务暂未配置")
+var ErrCoordinates = errors.New("定位坐标无效")
+
+type Weather struct {
+	Description string `json:"description"`
+	Temperature string `json:"temperature"`
+	ReportedAt  string `json:"reported_at"`
+}
+type Result struct {
+	LocationName string   `json:"location_name"`
+	City         string   `json:"city"`
+	District     string   `json:"district"`
+	Weather      *Weather `json:"weather"`
+}
+type cached struct {
+	result  Result
+	expires time.Time
+}
+type Client struct {
+	key     string
+	baseURL string
+	http    *http.Client
+	mu      sync.Mutex
+	cache   map[string]cached
+}
+
+func New(key string) *Client {
+	return &Client{key: key, baseURL: "https://restapi.amap.com", http: &http.Client{Timeout: 5 * time.Second}, cache: make(map[string]cached)}
+}
+
+// AMap returns [] instead of an empty string for some address components.
+func addressText(raw json.RawMessage) string {
+	var text string
+	_ = json.Unmarshal(raw, &text)
+	return text
+}
+func (c *Client) get(ctx context.Context, path string, params url.Values, target any) error {
+	params.Set("key", c.key)
+	params.Set("output", "JSON")
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, c.baseURL+path+"?"+params.Encode(), nil)
+	if err != nil {
+		return errors.New("位置服务请求失败")
+	}
+	res, err := c.http.Do(req)
+	// Never return the transport error: it may contain the URL and API key.
+	if err != nil {
+		return errors.New("位置服务暂时不可用")
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusOK {
+		return errors.New("位置服务暂时不可用")
+	}
+	if err := json.NewDecoder(io.LimitReader(res.Body, 1<<20)).Decode(target); err != nil {
+		return errors.New("位置服务响应无效")
+	}
+	return nil
+}
+func (c *Client) Lookup(ctx context.Context, latitude, longitude float64) (Result, error) {
+	if math.IsNaN(latitude) || math.IsNaN(longitude) || math.IsInf(latitude, 0) || math.IsInf(longitude, 0) || latitude < -90 || latitude > 90 || longitude < -180 || longitude > 180 {
+		return Result{}, ErrCoordinates
+	}
+	if c.key == "" {
+		return Result{}, ErrNotConfigured
+	}
+	cacheKey := fmt.Sprintf("%.3f,%.3f", longitude, latitude)
+	c.mu.Lock()
+	hit, found := c.cache[cacheKey]
+	c.mu.Unlock()
+	if found && time.Now().Before(hit.expires) {
+		return hit.result, nil
+	}
+	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+	var geo struct {
+		Status    string `json:"status"`
+		Regeocode struct {
+			Address struct {
+				Province json.RawMessage `json:"province"`
+				City     json.RawMessage `json:"city"`
+				District json.RawMessage `json:"district"`
+				Adcode   string          `json:"adcode"`
+			} `json:"addressComponent"`
+		} `json:"regeocode"`
+	}
+	err := c.get(ctx, "/v3/geocode/regeo", url.Values{"location": {fmt.Sprintf("%.6f,%.6f", longitude, latitude)}, "extensions": {"base"}}, &geo)
+	if err != nil {
+		return Result{}, err
+	}
+	if geo.Status != "1" {
+		return Result{}, errors.New("所在城市获取失败，请稍后重试")
+	}
+	address := geo.Regeocode.Address
+	city := addressText(address.City)
+	if city == "" {
+		city = addressText(address.Province)
+	}
+	district := addressText(address.District)
+	if city == "" || address.Adcode == "" {
+		return Result{}, errors.New("当前位置暂不支持天气查询")
+	}
+	result := Result{City: city, District: district, LocationName: city}
+	if district != "" && district != city {
+		result.LocationName += " · " + district
+	}
+	var weather struct {
+		Status string `json:"status"`
+		Lives  []struct {
+			Description string `json:"weather"`
+			Temperature string `json:"temperature"`
+			ReportedAt  string `json:"reporttime"`
+		} `json:"lives"`
+	}
+	err = c.get(ctx, "/v3/weather/weatherInfo", url.Values{"city": {address.Adcode}, "extensions": {"base"}}, &weather)
+	if err == nil && weather.Status == "1" && len(weather.Lives) > 0 {
+		live := weather.Lives[0]
+		if strings.TrimSpace(live.Description) != "" && live.Temperature != "" {
+			result.Weather = &Weather{live.Description, live.Temperature, live.ReportedAt}
+		}
+	}
+	// Keep the city even if the weather provider fails; retry missing weather next time.
+	if result.Weather != nil {
+		c.mu.Lock()
+		if len(c.cache) >= 256 {
+			clear(c.cache)
+		}
+		c.cache[cacheKey] = cached{result, time.Now().Add(15 * time.Minute)}
+		c.mu.Unlock()
+	}
+	return result, nil
+}