From 136bd532a8dec253012e96445f9a7c5864e80c70 Mon Sep 17 00:00:00 2001
From: Tony Wu <tonywu3027@me.com>
Date: Sun, 20 Aug 2023 02:39:35 +0100
Subject: [PATCH] refactor(BloccConnections): encapsulate channels in
 BloccConnections

---
 .../ApprovedTransactionConfiguration.java     |  7 +++---
 .../dashboard/fabric/BloccConnections.java    | 22 +++++++++++++++++--
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/src/main/java/uk/ac/ic/doc/blocc/dashboard/approvedtransaction/ApprovedTransactionConfiguration.java b/src/main/java/uk/ac/ic/doc/blocc/dashboard/approvedtransaction/ApprovedTransactionConfiguration.java
index cd6646b..5a59ee4 100644
--- a/src/main/java/uk/ac/ic/doc/blocc/dashboard/approvedtransaction/ApprovedTransactionConfiguration.java
+++ b/src/main/java/uk/ac/ic/doc/blocc/dashboard/approvedtransaction/ApprovedTransactionConfiguration.java
@@ -5,7 +5,6 @@
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import org.hyperledger.fabric.client.CloseableIterator;
-import org.hyperledger.fabric.client.Gateway;
 import org.hyperledger.fabric.client.Network;
 import org.hyperledger.fabric.protos.common.Block;
 import org.hyperledger.fabric.protos.common.Envelope;
@@ -41,13 +40,13 @@ public ApprovedTransactionConfiguration(ApprovedTransactionService service,
   CommandLineRunner commandLineRunner() {
     return args -> {
 
-      Gateway gateway = connections.getGateway();
-
       // TODO: read from external file
       List<Integer> availableChannelNums = List.of(5);
 
+      connections.connectToChannels(availableChannelNums);
+
       availableChannelNums.forEach(availableChannelNum -> {
-        Network channel = gateway.getNetwork(String.format("channel%d", availableChannelNum));
+        Network channel = connections.getChannel(availableChannelNum);
         CloseableIterator<Block> blockEvents =
             channel.newBlockEventsRequest().startBlock(0).build().getEvents();
 
diff --git a/src/main/java/uk/ac/ic/doc/blocc/dashboard/fabric/BloccConnections.java b/src/main/java/uk/ac/ic/doc/blocc/dashboard/fabric/BloccConnections.java
index 9c71e54..d75697d 100644
--- a/src/main/java/uk/ac/ic/doc/blocc/dashboard/fabric/BloccConnections.java
+++ b/src/main/java/uk/ac/ic/doc/blocc/dashboard/fabric/BloccConnections.java
@@ -13,9 +13,12 @@
 import java.security.PrivateKey;
 import java.security.cert.CertificateException;
 import java.security.cert.X509Certificate;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 import org.hyperledger.fabric.client.Gateway;
+import org.hyperledger.fabric.client.Network;
 import org.hyperledger.fabric.client.identity.Identities;
 import org.hyperledger.fabric.client.identity.Identity;
 import org.hyperledger.fabric.client.identity.Signer;
@@ -45,6 +48,8 @@ public class BloccConnections implements DisposableBean {
   private final Gateway gateway;
   private final ManagedChannel grcpChannel;
 
+  private final Map<Integer, Network> channels = new HashMap<>();
+
   /**
    * Establish gRPC connection to create a Gateway, which can be used to connect to the BLOCC
    * network. The following environmental variables need to be provided:
@@ -165,8 +170,21 @@ private Path getPrivateKeyPath() throws IOException {
     }
   }
 
-  public Gateway getGateway() {
-    return gateway;
+  public void connectToChannel(int channelNum) {
+    String channelName = String.format("channel%d", channelNum);
+    if (channels.containsKey(channelNum)) {
+      throw new IllegalArgumentException(String.format("%s already exists", channelName));
+    }
+
+    channels.put(channelNum, gateway.getNetwork(channelName));
+  }
+
+  public Network getChannel(int channelNum) {
+    return channels.get(channelNum);
+  }
+
+  public void connectToChannels(Iterable<Integer> channelNums) {
+    channelNums.forEach(this::connectToChannel);
   }
 
   @Override