From 472f00a1079fab626adce84d9285d8f07e433617 Mon Sep 17 00:00:00 2001
From: Jason Streifling <jason@streifling.com>
Date: Sat, 17 Aug 2024 20:15:35 +0200
Subject: [PATCH] Extracted verification logic for frontend into seperate
 function tokenIsVerified() and created ServePDFListe()

---
 cmd/frontend/firebase.go | 85 ++++++++++++++++++++++++++--------------
 1 file changed, 56 insertions(+), 29 deletions(-)

diff --git a/cmd/frontend/firebase.go b/cmd/frontend/firebase.go
index 1d28e1f..ca554b8 100644
--- a/cmd/frontend/firebase.go
+++ b/cmd/frontend/firebase.go
@@ -1,45 +1,72 @@
 package frontend
 
 import (
+	"encoding/json"
 	"log"
 	"net/http"
+	"os"
 	"strings"
 
 	b "streifling.com/jason/cpolis/cmd/backend"
 )
 
-func ServePDFs(c *b.Config) http.HandlerFunc {
+func tokenIsVerified(w http.ResponseWriter, r *http.Request) bool {
+	idToken := r.Header.Get("Authorization")
+	if idToken == "" {
+		http.Error(w, "Authorization header missing", http.StatusUnauthorized)
+	}
+
+	client, err := b.NewClient()
+	if err != nil {
+		log.Println(err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return false
+	}
+
+	_, err = client.Verify(idToken)
+	if err != nil {
+		log.Println(err)
+		http.Error(w, err.Error(), http.StatusUnauthorized)
+		return false
+	}
+
+	return true
+}
+
+func ServePDFList(c *b.Config) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		idToken := r.Header.Get("Authorization")
-		if idToken == "" {
-			http.Error(w, "Authorization header missing", http.StatusUnauthorized)
-		}
+		if tokenIsVerified(w, r) {
+			files, err := os.ReadDir(c.PDFDir)
+			if err != nil {
+				log.Println(err)
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
 
-		client, err := b.NewClient()
-		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())
+			}
 
-		_, err = client.Verify(idToken)
-		if err != nil {
-			log.Println(err)
-			http.Error(w, err.Error(), http.StatusUnauthorized)
-			return
-		}
-
-		pdfIDsString := r.PathValue("ids")
-		if err != nil {
-			log.Println(err)
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-
-		pdfIDs := strings.Split(pdfIDsString, ",")
-
-		for _, id := range pdfIDs {
-			http.ServeFile(w, r, id)
+			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)
+			}
 		}
 	}
 }