just make proxy a handler

url/proxy/proxy.go

@@ -0,0 +1,67 @@
+package proxy
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+func Handler(w http.ResponseWriter, r *http.Request) {
+	r.ParseForm()
+
+	// assuming /u/short-id
+	parts := strings.Split(r.URL.Path, "/")
+	if len(parts) < 3 {
+		return
+	}
+	// assuming its /u/ for url
+	if parts[1] != "u" {
+		return
+	}
+
+	// get the url id
+	//id := parts[2]
+
+	uri := url.URL{
+		Scheme: r.URL.Scheme,
+		Host:   r.URL.Host,
+		Path:   r.URL.Path,
+	}
+
+	// call the backend for the url
+	rsp, err := http.Get("https://api.m3o.com/url/proxy?shortURL=" + uri.String())
+	if err != nil {
+		http.Error(w, err.Error(), 500)
+		return
+	}
+	defer rsp.Body.Close()
+
+	if rsp.StatusCode != 200 {
+		http.Error(w, "unexpected error", 500)
+		return
+	}
+
+	result := map[string]interface{}{}
+
+	b, err := ioutil.ReadAll(rsp.Body)
+	if err != nil {
+		http.Error(w, err.Error(), 500)
+		return
+	}
+
+	if err := json.Unmarshal(b, &result); err != nil {
+		http.Error(w, err.Error(), 500)
+		return
+	}
+
+	// get the destination url
+	url, _ := result["destinationURL"].(string)
+	if len(url) == 0 {
+		return
+	}
+
+	// return the redirect url to caller
+	http.Redirect(w, r, url, 301)
+}