Refactor to enable RWGPS handler to be consumed by other modules.

cmd/serve-rwgps/main.go

@@ -1,19 +1,10 @@
 package main
 
 import (
-	"bytes"
-	"encoding/json"
-	"errors"
-	"fmt"
 	"log"
 	"net/http"
 	"os"
-	"strconv"
 
-	"github.com/dhconnelly/rtreego"
-
-	"github.com/ray1729/gpx-utils/pkg/cafes"
-	"github.com/ray1729/gpx-utils/pkg/placenames"
 	"github.com/ray1729/gpx-utils/pkg/rwgps"
 )
 
@@ -22,75 +13,11 @@ func main() {
 	if listenAddr == "" {
 		listenAddr = ":8000"
 	}
-	gs, err := placenames.NewGPXSummarizer()
+	rwgpsHandler, err := rwgps.NewHandler()
 	if err != nil {
 		log.Fatal(err)
 	}
-	gpxSummarizer = gs
+	http.Handle("/rwgps", rwgpsHandler)
-	http.HandleFunc("/rwgps", rwgpsHandler)
 	log.Printf("Listening for requests on %s", listenAddr)
 	log.Fatal(http.ListenAndServe(listenAddr, nil))
 }
-
-var gpxSummarizer *placenames.GPXSummarizer
-var stops = cafes.New()
-
-func rwgpsHandler(w http.ResponseWriter, r *http.Request) {
-	q := r.URL.Query()
-	rawRouteId := q.Get("routeId")
-	stopsName := q.Get("stops")
-	log.Printf("Handling request for routeId=%s stops=%s", rawRouteId, stopsName)
-	if rawRouteId == "" {
-		log.Printf("Missing routeId")
-		http.Error(w, "routeId is required", http.StatusBadRequest)
-		return
-	}
-	routeId, err := strconv.Atoi(rawRouteId)
-	if err != nil {
-		log.Println("Error parsing route id '%s': %v", rawRouteId, err)
-		http.Error(w, fmt.Sprintf("Invalid routeId: %s", rawRouteId), http.StatusBadRequest)
-		return
-	}
-	var stopsIndex *rtreego.Rtree
-	if stopsName != "" {
-		var err error
-		stopsIndex, err = stops.Get(stopsName)
-		if err != nil {
-			log.Println(err)
-			if errors.Is(err, cafes.ErrInvalidStops) {
-				http.Error(w, err.Error(), http.StatusBadRequest)
-			} else {
-				http.Error(w, err.Error(), http.StatusInternalServerError)
-			}
-			return
-		}
-	}
-	track, err := rwgps.FetchTrack(routeId)
-	if err != nil {
-		log.Println(err.Error())
-		switch err.(type) {
-		case *rwgps.ErrNotFound:
-			http.Error(w, err.Error(), http.StatusNotFound)
-		case *rwgps.ErrNotPublic:
-			http.Error(w, err.Error(), http.StatusForbidden)
-		default:
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-		}
-		return
-	}
-	summary, err := gpxSummarizer.SummarizeTrack(bytes.NewReader(track), stopsIndex)
-	if err != nil {
-		log.Printf("Error analyzing route %d: %v", routeId, err)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-	result, err := json.Marshal(summary)
-	if err != nil {
-		log.Printf("Error marshalling JSON for route %d: %v", routeId, err)
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-	w.Header().Add("Content-Type", "application/json")
-	w.WriteHeader(http.StatusOK)
-	w.Write(result)
-}

pkg/cafes/common.go

@@ -35,7 +35,7 @@ func (s *RefreshmentStop) Contains(p rtreego.Point) bool {
 }
 
 // TTL cache based on "9.7 Example: Concurrent Non-Blocking Cache" from
-// "The Go Programming Language", Alan A. A. Dovovan and Brian W. Kernighan
+// "The Go Programming Language", Alan A. A. Donovan and Brian W. Kernighan
 
 type result struct {
 	value *rtreego.Rtree

pkg/rwgps/handler.go

@@ -0,0 +1,90 @@
+package rwgps
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log"
+	"net/http"
+	"strconv"
+
+	"github.com/dhconnelly/rtreego"
+
+	"github.com/ray1729/gpx-utils/pkg/cafes"
+	"github.com/ray1729/gpx-utils/pkg/placenames"
+)
+
+type RWGPSHandler struct {
+	gs    *placenames.GPXSummarizer
+	stops *cafes.Cache
+}
+
+func NewHandler() (*RWGPSHandler, error) {
+	gs, err := placenames.NewGPXSummarizer()
+	if err != nil {
+		return nil, fmt.Errorf("error creating GPX summarizer: %v", err)
+	}
+	stops := cafes.New()
+	return &RWGPSHandler{gs, stops}, nil
+}
+
+func (h *RWGPSHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	q := r.URL.Query()
+	rawRouteId := q.Get("routeId")
+	stopsName := q.Get("stops")
+	log.Printf("Handling request for routeId=%s stops=%s", rawRouteId, stopsName)
+	if rawRouteId == "" {
+		log.Printf("Missing routeId")
+		http.Error(w, "routeId is required", http.StatusBadRequest)
+		return
+	}
+	routeId, err := strconv.Atoi(rawRouteId)
+	if err != nil {
+		log.Println("Error parsing route id '%s': %v", rawRouteId, err)
+		http.Error(w, fmt.Sprintf("Invalid routeId: %s", rawRouteId), http.StatusBadRequest)
+		return
+	}
+	var stopsIndex *rtreego.Rtree
+	if stopsName != "" {
+		var err error
+		stopsIndex, err = h.stops.Get(stopsName)
+		if err != nil {
+			log.Println(err)
+			if errors.Is(err, cafes.ErrInvalidStops) {
+				http.Error(w, err.Error(), http.StatusBadRequest)
+			} else {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+			}
+			return
+		}
+	}
+	track, err := FetchTrack(routeId)
+	if err != nil {
+		log.Println(err.Error())
+		switch err.(type) {
+		case *ErrNotFound:
+			http.Error(w, err.Error(), http.StatusNotFound)
+		case *ErrNotPublic:
+			http.Error(w, err.Error(), http.StatusForbidden)
+		default:
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+		}
+		return
+	}
+	summary, err := h.gs.SummarizeTrack(bytes.NewReader(track), stopsIndex)
+	if err != nil {
+		log.Printf("Error analyzing route %d: %v", routeId, err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	result, err := json.Marshal(summary)
+	if err != nil {
+		log.Printf("Error marshalling JSON for route %d: %v", routeId, err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.Header().Add("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	w.Write(result)
+}