feat(webui): implement logout process

pkg/webui/logout.go

@@ -0,0 +1,24 @@
+package webui
+
+import (
+	"html/template"
+	"net/http"
+
+	"git.adyxax.org/adyxax/tfstated/pkg/database"
+	"git.adyxax.org/adyxax/tfstated/pkg/model"
+)
+
+var logoutTemplate = template.Must(template.ParseFS(htmlFS, "html/base.html", "html/logout.html"))
+
+func handleLogoutGET(db *database.DB) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		session := r.Context().Value(model.SessionContextKey{})
+		err := db.DeleteSession(session.(*model.Session))
+		if err != nil {
+			errorResponse(w, http.StatusInternalServerError, err)
+			return
+		}
+		unsetSesssionCookie(w)
+		render(w, logoutTemplate, http.StatusOK, nil)
+	})
+}