don't shorten url if dest path is on same service. also default mime type

src/index.js

@@ -47,13 +47,19 @@ async function add(request,host,path) {
     const dest = data.get("u")
     console.log(dest)
     try {
-        new URL(dest)
+        var u = new URL(dest)
+        if (u.host !== host) {
             await KV.put(path, dest)
+        } else {
+            path = u.pathname.split("/")[1]
+        }
         await FILES.delete(path)
         return new Response(`https://${host}/${path}`, {status:201})
     } catch (e) {
         if (e instanceof TypeError) {
             await FILES.put(path, dest)
+            var type = dest.type
+            if (type === "undefined") type = "text/plain" // dammit sharex
             await KV.put(path,dest.type)
             return new Response(`https://${host}/${path}`, {status:201})
 //          return new Response("No valid URL provided",{status:400});