Added ability to get authorization code

internal/server/server.go

@@ -1,16 +1,48 @@
 package server
 
 import (
+	"davidallendj/oidc-auth/internal/util"
 	"fmt"
 	"net/http"
+	"net/url"
+	"os"
+	"strings"
 )
 
-func Start(host string, port int) error {
-	http.HandleFunc("/oauth/callback", getAuthorizationCode)
-	err := http.ListenAndServe(host+":"+fmt.Sprintf("%d", port), nil)
-	return err
+func WaitForAuthorizationCode(host string, port int) (string, error) {
+	var code string
+	s := &http.Server{
+		Addr: fmt.Sprintf("%s:%d", host, port),
+	}
+	http.HandleFunc("/oauth/callback", func(w http.ResponseWriter, r *http.Request) {
+		// get the code from the OIDC provider
+		if r != nil {
+			code = r.URL.Query().Get("code")
+			fmt.Printf("Authorization Code: %v\n", code)
+		}
+		s.Close()
+
+	})
+	return code, s.ListenAndServe()
 }
 
-func getAuthorizationCode(w http.ResponseWriter, r *http.Request) {
-	fmt.Printf("response from OIDC provider: %v\n", r)
+func FetchToken(code string, remoteUrl string, clientId string, clientSecret string, state string, redirectUri []string) (string, error) {
+	var token string
+	data := url.Values{
+		"grant_type":    {"authorization_code"},
+		"code":          {code},
+		"client_id":     {clientId},
+		"client_secret": {clientSecret},
+		"state":         {state},
+		"redirect_uri":  {util.EncodeURL(strings.Join(redirectUri, ","))},
+	}
+	res, err := http.PostForm(remoteUrl, data)
+	if err != nil {
+		fmt.Printf("failed to get token: %s\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Printf("request URL: %s\n", remoteUrl)
+	fmt.Printf("token response: %v\n", res)
+	return token, nil
 }