cmd/pkgserver: api versioning

cmd/pkgserver/api.go

@@ -10,15 +10,29 @@ import (
 	"strconv"
 	"strings"
 
+	"hakurei.app/internal/info"
 	"hakurei.app/internal/rosa"
 )
 
-func serveCount(index *PackageIndex) func(http.ResponseWriter, *http.Request) {
+type InfoPayload struct {
+	Count          int    `json:"count"`
+	HakureiVersion string `json:"hakurei_version"`
+}
+
+func NewInfoPayload(index *PackageIndex) InfoPayload {
+	count := len(index.sorts[0])
+	return InfoPayload{
+		Count:          count,
+		HakureiVersion: info.Version(),
+	}
+}
+
+func serveInfo(index *PackageIndex) func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		count := len(index.names)
-		w.Write([]byte(strconv.Itoa(count)))
+		w.Header().Set("Content-Type", "text/json; charset=utf-8")
+		w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+		WritePayload(w, NewInfoPayload(index))
 	}
 }
 
@@ -91,22 +105,26 @@ func serveGet(index *PackageIndex) func(http.ResponseWriter, *http.Request) {
 			return
 		}
 		values := index.sorts[sort][i:min(i+limit, len(index.sorts[sort]))]
-		payload := NewGetPayload(values)
-		w.Header().Set("Content-Type", "application/json; charset=utf-8")
-		w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
-		w.WriteHeader(http.StatusOK)
-		b, err := json.Marshal(payload)
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-		}
-		_, err = bytes.NewBuffer(b).WriteTo(w)
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-		}
+		WritePayload(w, NewGetPayload(values))
 	}
 }
+
+const ApiVersion = "v1"
+
 func apiRoutes(index *PackageIndex) {
-	http.HandleFunc("GET /api/count", serveCount(index))
-	http.HandleFunc("GET /api/get", serveGet(index))
-	http.HandleFunc("GET /api/status/", serveStatus(index))
+	http.HandleFunc(fmt.Sprintf("GET /api/%s/info", ApiVersion), serveInfo(index))
+	http.HandleFunc(fmt.Sprintf("GET /api/%s/get", ApiVersion), serveGet(index))
+	http.HandleFunc(fmt.Sprintf("GET /api/%s/status/", ApiVersion), serveStatus(index))
+}
+
+func WritePayload(w http.ResponseWriter, payload any) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	w.Header().Set("Pragma", "no-cache")
+	w.Header().Set("Expires", "0")
+	w.WriteHeader(http.StatusOK)
+	err := json.NewEncoder(w).Encode(payload)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
 }