logo

internal/server/server.go

@@ -28,6 +28,7 @@ func New(secret string, chartMax int, st *store.Store, templates fs.FS) *Server
 func (s *Server) Routes() http.Handler {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", s.handleIndex)
+	mux.HandleFunc("/logo.png", s.handleLogo)
 	mux.HandleFunc("/favicon.svg", s.handleFavicon)
 	mux.HandleFunc("/write", s.handleWrite)
 	return mux
@@ -70,6 +71,22 @@ func (s *Server) handleFavicon(w http.ResponseWriter, r *http.Request) {
 	_, _ = w.Write([]byte(faviconSVG))
 }
 
+func (s *Server) handleLogo(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path != "/logo.png" {
+		http.NotFound(w, r)
+		return
+	}
+
+	data, err := fs.ReadFile(s.templates, "static/logo.png")
+	if err != nil {
+		http.Error(w, "asset missing", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "image/png")
+	_, _ = w.Write(data)
+}
+
 func (s *Server) handleWrite(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodPost {
 		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)

main_test.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"os"
+	"image/png"
 	"strings"
 	"testing"
 	"time"
@@ -127,3 +128,21 @@ func TestBuildHistoryChart(t *testing.T) {
 		}
 	}
 }
+
+func TestLogoServedAsPng(t *testing.T) {
+	srv := server.New("secret", 0, &store.Store{}, embeddedStatic)
+	req := httptest.NewRequest(http.MethodGet, "/logo.png", nil)
+	rec := httptest.NewRecorder()
+
+	srv.Routes().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+	if got := rec.Header().Get("Content-Type"); got != "image/png" {
+		t.Fatalf("content-type = %q, want image/png", got)
+	}
+	if _, err := png.Decode(bytes.NewReader(rec.Body.Bytes())); err != nil {
+		t.Fatalf("logo is not a valid png: %v", err)
+	}
+}

static/index.html

@@ -14,10 +14,12 @@
     .updated-at { margin-top: 0.5rem; font-size: 0.875rem; color: #64748b; }
     .chart { margin-top: 1.25rem; width: min(92vw, 42rem); }
     .chart-svg { display: block; width: 100%; height: auto; }
+    .logo { display: block; width: min(80vw, 36rem); height: auto; margin: 0 auto 0; }
   </style>
 </head>
 <body>
     <main>
+      <img class="logo" src="/logo.png" alt="Power Watts logo">
       <div class="value">{{.Watts}} W</div>
       <div class="updated-at">Last updated: {{.UpdatedAt}}</div>
       <div class="chart">{{.HistoryChart}}</div>