From b75be9bc98cc8c7bed56ad9a5b3c51fa4b85a613 Mon Sep 17 00:00:00 2001
From: garritfra <garritfranke@gmail.com>
Date: Sun, 23 Dec 2018 21:08:25 +0100
Subject: [PATCH] Update AddPeer Method

---
 core/Blockchain.go  | 25 +++++++++++++++++++++++--
 server/webserver.go |  5 ++++-
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/core/Blockchain.go b/core/Blockchain.go
index adc332e..2e6ac7a 100644
--- a/core/Blockchain.go
+++ b/core/Blockchain.go
@@ -2,6 +2,7 @@ package core
 
 import (
 	"log"
+	"net/http"
 	"strings"
 	"time"
 )
@@ -64,8 +65,28 @@ func (bc *Blockchain) GetLastHash() string {
 }
 
 // AddPeer appends the IP address to the list of peers known to the chain
-func (bc *Blockchain) AddPeer(peer string) {
-	bc.Peers = append(bc.Peers, peer)
+func (bc *Blockchain) AddPeer(peer string) (resp *http.Response, err error) {
+	resp, err = http.Get("http://" + peer)
+
+	// Return Error, if an error occured
+	if err != nil {
+		return nil, err
+	}
+
+	// Add Peer, if it is not already in the list
+	if !contains(bc.Peers, peer) {
+		bc.Peers = append(bc.Peers, peer)
+	}
+	return resp, nil
+}
+
+func contains(s []string, e string) bool {
+	for _, a := range s {
+		if a == e {
+			return true
+		}
+	}
+	return false
 }
 
 // IsValid checks, if the chain has any faulty blocks
diff --git a/server/webserver.go b/server/webserver.go
index a9de49a..eac4632 100644
--- a/server/webserver.go
+++ b/server/webserver.go
@@ -81,7 +81,10 @@ func handleAddPeers(w http.ResponseWriter, r *http.Request) {
 
 	if err == nil {
 		for _, peer := range receivedPeers {
-			blockchain.AddPeer(peer)
+			_, err := blockchain.AddPeer(peer)
+			if err != nil {
+				handleError(err, w, r)
+			}
 		}
 	} else {
 		handleError(err, w, r)