add caching and change the layout a bit

utils.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"path"
+	"text/template"
+
+	"github.com/allegro/bigcache/v3"
+)
+
+var cache *bigcache.BigCache
+
+func setCache(key string, entry any) error {
+	data, err := json.Marshal(&entry)
+	if err != nil {
+		return err
+	}
+
+	return cache.Set(key, data)
+}
+
+func getCache(key string) (any, error) {
+	data, err := cache.Get(key)
+	if err != nil {
+		return nil, err
+	}
+
+	var decoded any
+
+	if err = json.Unmarshal(data, &decoded); err != nil {
+		return nil, err
+	}
+
+	return decoded, nil
+}
+
+func fatal(err any) {
+	log.Fatalf("[ERR] %s\n", err)
+}
+
+func info(s string) {
+	log.Printf("[INFO] %s\n", s)
+}
+
+func write(w http.ResponseWriter, status int, data []byte) {
+	w.WriteHeader(status)
+	w.Write(data)
+}
+
+func securityHeaders(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		csp := "default-src 'self'; script-src 'self'; style-src 'self'; img-src 'self' images.genius.com; object-src 'none'"
+		w.Header().Add("content-security-policy", csp)
+		w.Header().Add("referrer-policy", "no-referrer")
+		w.Header().Add("x-content-type-options", "nosniff")
+		next.ServeHTTP(w, r)
+	})
+}
+
+func render(w http.ResponseWriter, data any) {
+	t, err := template.ParseFiles(path.Join("views/lyrics.tmpl"))
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	if err = t.Execute(w, data); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+}