feat: add instances handler

Makefile

@@ -4,3 +4,5 @@ gentempl:
 	@command -v templ &> /dev/null || go install github.com/a-h/templ/cmd/templ@latest
 build:gentempl
 	templ generate && go build -ldflags="-X 'github.com/rramiachraf/dumb/data.Version=$(VERSION)' -s -w"
+fmt:
+	templ fmt .

handlers/cache.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"context"
 	"encoding/json"
 	"time"
 
@@ -9,10 +10,10 @@ import (
 )
 
 type cachable interface {
-	data.Album | data.Song | data.Annotation
+	data.Album | data.Song | data.Annotation | []byte
 }
 
-var c, _ = bigcache.NewBigCache(bigcache.DefaultConfig(time.Hour * 24))
+var c, _ = bigcache.New(context.Background(), bigcache.DefaultConfig(time.Hour*24))
 
 func setCache(key string, entry interface{}) error {
 	data, err := json.Marshal(&entry)

handlers/instances.go

@@ -0,0 +1,56 @@
+package handlers
+
+import (
+	"context"
+	"io"
+	"net/http"
+
+	"github.com/rramiachraf/dumb/views"
+	"github.com/sirupsen/logrus"
+)
+
+const ContentTypeJSON = "application/json"
+
+// TODO: move this to utils, so it can be used by other handlers.
+func sendError(err error, status int, msg string, l *logrus.Logger, w http.ResponseWriter) {
+	l.Errorln(err)
+	w.WriteHeader(status)
+	if err := views.ErrorPage(status, msg).Render(context.Background(), w); err != nil {
+		l.Errorln(err)
+	}
+}
+
+func Instances(l *logrus.Logger) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if instances, err := getCache[[]byte]("instances"); err == nil {
+			w.Header().Set("content-type", ContentTypeJSON)
+			_, err = w.Write(instances)
+			if err == nil {
+				return
+			}
+		}
+
+		res, err := sendRequest("https://raw.githubusercontent.com/rramiachraf/dumb/main/instances.json")
+		if err != nil {
+			sendError(err, http.StatusInternalServerError, "something went wrong", l, w)
+			return
+		}
+
+		defer res.Body.Close()
+
+		instances, err := io.ReadAll(res.Body)
+		if err != nil {
+			sendError(err, http.StatusInternalServerError, "something went wrong", l, w)
+			return
+		}
+
+		w.Header().Set("content-type", ContentTypeJSON)
+		if _, err = w.Write(instances); err != nil {
+			l.Errorln(err)
+		}
+
+		if err = setCache("instances", instances); err != nil {
+			l.Errorln(err)
+		}
+	}
+}

main.go

@@ -29,6 +29,7 @@ func main() {
 	r.HandleFunc("/images/{filename}.{ext}", handlers.ImageProxy(logger)).Methods("GET")
 	r.HandleFunc("/search", handlers.Search(logger)).Methods("GET")
 	r.HandleFunc("/{id}/{artist-song}/{verse}/annotations", handlers.Annotations(logger)).Methods("GET")
+	r.HandleFunc("/instances.json", handlers.Instances(logger)).Methods("GET")
 	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
 	r.NotFoundHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusNotFound)

static/style.css

@@ -245,7 +245,7 @@ footer {
 	padding: 1rem 0;
 }
 
-#footer_container {
+#footer-container {
 	width: 1024px;
 	display: flex;
 	justify-content: space-between;
@@ -253,6 +253,11 @@ footer {
 	margin: 0 auto;
 }
 
+#footer-links {
+	display: flex;
+	gap: 1rem;
+}
+
 #version {
 	font-size: 1.3rem;
 	color: #1b1b1b;

views/footer.templ

@@ -4,8 +4,11 @@ import "github.com/rramiachraf/dumb/data"
 
 templ footer() {
 	<footer>
-		<div id="footer_container">
+		<div id="footer-container">
+			<div id="footer-links">
 				<a rel="noopener noreferrer" target="_blank" href="https://github.com/rramiachraf/dumb">Source Code</a>
+				<a rel="noopener noreferrer" target="_blank" href="/instances.json">Instances</a>
+			</div>
 			<p id="version">{ data.Version }</p>
 		</div>
 	</footer>