internal/component => internal/dis/component

internal/dis/component/home/home.go

@@ -0,0 +1,70 @@
+package home
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component"
+	"github.com/FAU-CDI/wisski-distillery/internal/dis/component/instances"
+	"github.com/FAU-CDI/wisski-distillery/pkg/lazy"
+	"github.com/tkw1536/goprogram/stream"
+)
+
+type Home struct {
+	component.Base
+
+	Instances *instances.Instances
+
+	RefreshInterval time.Duration
+
+	redirect      lazy.Lazy[*Redirect]
+	instanceNames lazy.Lazy[map[string]struct{}]
+	homeBytes     lazy.Lazy[[]byte]
+}
+
+func (*Home) Routes() []string { return []string{"/"} }
+
+func (home *Home) Handler(route string, context context.Context, io stream.IOStream) (http.Handler, error) {
+	home.updateRedirect(context, io)
+	home.updateInstances(context, io)
+	home.updateRender(context, io)
+	return home, nil
+}
+
+func (home *Home) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	slug, ok := home.Config.SlugFromHost(r.Host)
+	switch {
+	case !ok:
+		http.NotFound(w, r)
+	case slug != "":
+		home.serveWissKI(w, slug, r)
+	default:
+		home.serveRoot(w, r)
+	}
+}
+
+func (home *Home) serveRoot(w http.ResponseWriter, r *http.Request) {
+	// not the root url => server the fallback
+	if !(r.URL.Path == "" || r.URL.Path == "/") {
+		home.redirect.Get(nil).ServeHTTP(w, r)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/html")
+	w.WriteHeader(http.StatusAccepted)
+	w.Write(home.homeBytes.Get(nil))
+}
+
+func (home *Home) serveWissKI(w http.ResponseWriter, slug string, r *http.Request) {
+	if _, ok := home.instanceNames.Get(nil)[slug]; !ok {
+		// Get(nil) guaranteed to work by precondition
+		w.WriteHeader(http.StatusNotFound)
+		fmt.Fprintf(w, "WissKI %q not found\n", slug)
+		return
+	}
+
+	w.WriteHeader(http.StatusBadGateway)
+	fmt.Fprintf(w, "WissKI %q is currently offline\n", slug)
+}