Extracted verification logic for frontend into seperate function tokenIsVerified() and created ServePDFListe()

cmd/frontend/firebase.go

@@ -1,15 +1,16 @@
 package frontend
 
 import (
+	"encoding/json"
 	"log"
 	"net/http"
+	"os"
 	"strings"
 
 	b "streifling.com/jason/cpolis/cmd/backend"
 )
 
-func ServePDFs(c *b.Config) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
+func tokenIsVerified(w http.ResponseWriter, r *http.Request) bool {
 	idToken := r.Header.Get("Authorization")
 	if idToken == "" {
 		http.Error(w, "Authorization header missing", http.StatusUnauthorized)
@@ -19,27 +20,53 @@ func ServePDFs(c *b.Config) http.HandlerFunc {
 	if err != nil {
 		log.Println(err)
 		http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
+		return false
 	}
 
 	_, err = client.Verify(idToken)
 	if err != nil {
 		log.Println(err)
 		http.Error(w, err.Error(), http.StatusUnauthorized)
-			return
+		return false
 	}
 
-		pdfIDsString := r.PathValue("ids")
+	return true
+}
+
+func ServePDFList(c *b.Config) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if tokenIsVerified(w, r) {
+			files, err := os.ReadDir(c.PDFDir)
 			if err != nil {
 				log.Println(err)
 				http.Error(w, err.Error(), http.StatusInternalServerError)
 				return
 			}
 
+			fileNames := make([]string, 0)
+			for _, file := range files {
+				fileNames = append(fileNames, file.Name())
+			}
+
+			w.Header().Set("Content-Type", "application/json")
+			if err = json.NewEncoder(w).Encode(fileNames); err != nil {
+				log.Println(err)
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+		}
+	}
+}
+
+func ServePDFs(c *b.Config) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if tokenIsVerified(w, r) {
+			pdfIDsString := r.PathValue("ids")
 			pdfIDs := strings.Split(pdfIDsString, ",")
 
 			for _, id := range pdfIDs {
 				http.ServeFile(w, r, id)
 			}
 		}
+	}
 }