Go言語を使用して注文システムのテイクアウト配達追跡機能を開発する方法

func getLocation(address string) (float64, float64, error) {
    apiUrl := fmt.Sprintf("http://api.map.baidu.com/geocoding/v3/?address=%s&output=json&ak=%s", address, BaiduAk)

    resp, err := http.Get(apiUrl)
    if err != nil {
        return 0, 0, err
    }

    defer resp.Body.Close()
    body, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        return 0, 0, err
    }

    type location struct {
        Lon float64 `json:"lng"`
        Lat float64 `json:"lat"`
    }
    type result struct {
        Location location `json:"location"`
    }
    type apiResult struct {
        Result result `json:"result"`
    }

    var resultData apiResult
    err = json.Unmarshal(body, &resultData)
    if err != nil {
        return 0, 0, err
    }

    return resultData.Result.Location.Lon, resultData.Result.Location.Lat, nil
}

func getClosestPointOnLineString(lineString geom.LineString, point geom.Point) geom.Point {
    tree := geo.NewTree(2)
    for _, p := range lineString {
        tree.Insert(geo.NewItem(p.XY(), nil))
    }
    nearest := tree.NearestNeighbors(geo.NewItem(point.XY(), nil), 1, -1)
    result := nearest[0].Object().(geo.Pointer).Point()
    return result
}

func getDistance(point1, point2 geom.Point) float64 {
    x := point1.X() - point2.X()
    y := point1.Y() - point2.Y()
    return math.Sqrt(x*x + y*y)
}

func isPointOnLineString(lineString geom.LineString, point geom.Point, threshold float64) bool {
    closestPoint := getClosestPointOnLineString(lineString, point)
    distance := getDistance(closestPoint, point)
    return distance <= threshold
}

var upgrader = websocket.Upgrader{
    ReadBufferSize:    1024,
    WriteBufferSize:   1024,
    CheckOrigin: func(r *http.Request) bool {
        return true
    },
}

func handleSocket(w http.ResponseWriter, r *http.Request) {
    conn, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        log.Println(err)
        return
    }

    for {
        message := []byte("Hello, world!")
        err = conn.WriteMessage(websocket.TextMessage, message)
        if err != nil {
            log.Println(err)
            break
        }
    }
}

func main() {
    http.HandleFunc("/socket", handleSocket)
    http.ListenAndServe(":8080", nil)
}