Implemented functionality for reading grandpa consensus message

src/main/java/com/limechain/network/protocol/grandpa/messages/consensus/GrandpaConsensusMessage.java

@@ -0,0 +1,16 @@
+package com.limechain.network.protocol.grandpa.messages.consensus;
+
+import com.limechain.chain.lightsyncstate.Authority;
+import lombok.Data;
+
+import java.math.BigInteger;
+import java.util.List;
+
+@Data
+public class GrandpaConsensusMessage {
+    private long bestFinalizedBlock;
+    private List<Authority> authorities;
+    private BigInteger disabledAuthority;
+    private long delay;
+    private GrandpaConsensusMessageFormat format;
+}

src/main/java/com/limechain/network/protocol/grandpa/messages/consensus/GrandpaConsensusMessageFormat.java

@@ -0,0 +1,23 @@
+package com.limechain.network.protocol.grandpa.messages.consensus;
+
+import lombok.Getter;
+
+@Getter
+public enum GrandpaConsensusMessageFormat {
+    GRANDPA_SCHEDULED_CHANGE(1), GRANDPA_FORCED_CHANGE(2), GRANDPA_ON_DISABLED(3), GRANDPA_PAUSE(4), GRANDPA_RESUME(5);
+
+    private final int format;
+
+    GrandpaConsensusMessageFormat(int format) {
+        this.format = format;
+    }
+
+    public static GrandpaConsensusMessageFormat fromFormat(byte format) {
+        for (GrandpaConsensusMessageFormat messageFormat : values()) {
+            if (messageFormat.getFormat() == format) {
+                return messageFormat;
+            }
+        }
+        throw new IllegalArgumentException("Unknown grandpa consensus message format: " + format);
+    }
+}

src/main/java/com/limechain/network/protocol/grandpa/messages/consensus/GrandpaConsensusMessageReader.java

@@ -0,0 +1,39 @@
+package com.limechain.network.protocol.grandpa.messages.consensus;
+
+import com.limechain.chain.lightsyncstate.Authority;
+import com.limechain.chain.lightsyncstate.scale.AuthorityReader;
+import io.emeraldpay.polkaj.scale.ScaleCodecReader;
+import io.emeraldpay.polkaj.scale.ScaleReader;
+import io.emeraldpay.polkaj.scale.reader.ListReader;
+import io.emeraldpay.polkaj.scale.reader.UInt64Reader;
+
+import java.util.List;
+
+public class GrandpaConsensusMessageReader implements ScaleReader<GrandpaConsensusMessage> {
+
+    @Override
+    public GrandpaConsensusMessage read(ScaleCodecReader reader) {
+        GrandpaConsensusMessage grandpaConsensusMessage = new GrandpaConsensusMessage();
+        GrandpaConsensusMessageFormat format = GrandpaConsensusMessageFormat.fromFormat(reader.readByte());
+        grandpaConsensusMessage.setFormat(format);
+        switch (format) {
+            case GRANDPA_SCHEDULED_CHANGE -> {
+                List<Authority> authorities = reader.read(new ListReader<>(new AuthorityReader()));
+                long delay = reader.readUint32();
+                grandpaConsensusMessage.setAuthorities(authorities);
+                grandpaConsensusMessage.setDelay(delay);
+            }
+            case GRANDPA_FORCED_CHANGE -> {
+                long bestFinalizedBlock = reader.readUint32();
+                List<Authority> authorities = reader.read(new ListReader<>(new AuthorityReader()));
+                long delay = reader.readUint32();
+                grandpaConsensusMessage.setBestFinalizedBlock(bestFinalizedBlock);
+                grandpaConsensusMessage.setAuthorities(authorities);
+                grandpaConsensusMessage.setDelay(delay);
+            }
+            case GRANDPA_ON_DISABLED -> grandpaConsensusMessage.setDisabledAuthority(new UInt64Reader().read(reader));
+            case GRANDPA_PAUSE, GRANDPA_RESUME -> grandpaConsensusMessage.setDelay(reader.readUint32());
+        }
+        return grandpaConsensusMessage;
+    }
+}

src/main/java/com/limechain/network/protocol/warp/DigestHelper.java

@@ -4,6 +4,8 @@
 import com.limechain.babe.consensus.scale.BabeConsensusMessageReader;
 import com.limechain.babe.predigest.BabePreDigest;
 import com.limechain.babe.predigest.scale.PreDigestReader;
+import com.limechain.network.protocol.grandpa.messages.consensus.GrandpaConsensusMessage;
+import com.limechain.network.protocol.grandpa.messages.consensus.GrandpaConsensusMessageReader;
 import com.limechain.network.protocol.warp.dto.BlockHeader;
 import com.limechain.network.protocol.warp.dto.ConsensusEngine;
 import com.limechain.network.protocol.warp.dto.DigestType;
@@ -32,6 +34,15 @@ public static Optional<BabeConsensusMessage> getBabeConsensusMessage(HeaderDiges
                 .map(message -> ScaleUtils.Decode.decode(message, new BabeConsensusMessageReader()));
     }
 
+    public static Optional<GrandpaConsensusMessage> getGrandpaConsensusMessage(HeaderDigest[] headerDigests) {
+        return Arrays.stream(headerDigests)
+                .filter(headerDigest -> DigestType.CONSENSUS_MESSAGE.equals(headerDigest.getType()) &&
+                        ConsensusEngine.GRANDPA.equals(headerDigest.getId()))
+                .findFirst()
+                .map(HeaderDigest::getMessage)
+                .map(message -> ScaleUtils.Decode.decode(message, new GrandpaConsensusMessageReader()));
+    }
+
     public static Optional<BabePreDigest> getBabePreRuntimeDigest(HeaderDigest[] headerDigests) {
         return Arrays.stream(headerDigests)
                 .filter(headerDigest -> DigestType.PRE_RUNTIME.equals(headerDigest.getType()) &&

src/test/java/com/limechain/network/protocol/grandpa/messages/consensus/GrandpaConsensusMessageReaderTest.java

@@ -0,0 +1,71 @@
+package com.limechain.network.protocol.grandpa.messages.consensus;
+
+import com.limechain.utils.StringUtils;
+import io.emeraldpay.polkaj.scale.ScaleCodecReader;
+import org.junit.jupiter.api.Test;
+
+import java.math.BigInteger;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+public class GrandpaConsensusMessageReaderTest {
+
+    private final GrandpaConsensusMessageReader reader = new GrandpaConsensusMessageReader();
+
+    @Test
+    public void testScheduledChangeInput() {
+        String hexWithPrefix = "0x0104010101010101010101010101010101010101010101010101010101010101010101020000000000000003000000";
+        byte[] input = StringUtils.hexToBytes(hexWithPrefix);
+        GrandpaConsensusMessage message = reader.read(new ScaleCodecReader(input));
+        assertNotNull(message);
+        assertEquals(GrandpaConsensusMessageFormat.GRANDPA_SCHEDULED_CHANGE, message.getFormat());
+        assertNotNull(message.getAuthorities());
+        assertEquals(1, message.getAuthorities().size());
+        assertEquals(768L, message.getDelay());
+    }
+
+    @Test
+    public void testForcedChangeInput() {
+        String hexWithPrefix = "0x020300000004010101010101010101010101010101010101010101010101010101010101010101020000000000000003000000";
+        byte[] input = StringUtils.hexToBytes(hexWithPrefix);
+        GrandpaConsensusMessage message = reader.read(new ScaleCodecReader(input));
+        assertNotNull(message);
+        assertEquals(GrandpaConsensusMessageFormat.GRANDPA_FORCED_CHANGE, message.getFormat());
+        assertEquals(3, message.getBestFinalizedBlock());
+        assertNotNull(message.getAuthorities());
+
+        assertEquals(1, message.getAuthorities().size());
+        assertEquals(768L, message.getDelay());
+    }
+
+    @Test
+    public void testOnDisabledInput() {
+        String hexWithPrefix = "0x0315cd5b0700000000";
+        byte[] input = StringUtils.hexToBytes(hexWithPrefix);
+        GrandpaConsensusMessage message = reader.read(new ScaleCodecReader(input));
+        assertNotNull(message);
+        assertEquals(GrandpaConsensusMessageFormat.GRANDPA_ON_DISABLED, message.getFormat());
+        assertEquals(BigInteger.valueOf(123456789L), message.getDisabledAuthority());
+    }
+
+    @Test
+    public void testPauseInput() {
+        String hexWithPrefix = "0x0414000000";
+        byte[] input = StringUtils.hexToBytes(hexWithPrefix);
+        GrandpaConsensusMessage message = reader.read(new ScaleCodecReader(input));
+        assertNotNull(message);
+        assertEquals(GrandpaConsensusMessageFormat.GRANDPA_PAUSE, message.getFormat());
+        assertEquals(20L, message.getDelay());
+    }
+
+    @Test
+    public void testResumeInput() {
+        String hexWithPrefix = "0x0519000000";
+        byte[] input = StringUtils.hexToBytes(hexWithPrefix);
+        GrandpaConsensusMessage message = reader.read(new ScaleCodecReader(input));
+        assertNotNull(message);
+        assertEquals(GrandpaConsensusMessageFormat.GRANDPA_RESUME, message.getFormat());
+        assertEquals(25L, message.getDelay());
+    }
+}

src/test/java/com/limechain/network/protocol/warp/DigestHelperTest.java

@@ -2,6 +2,7 @@
 
 import com.limechain.babe.consensus.BabeConsensusMessageFormat;
 import com.limechain.babe.predigest.PreDigestType;
+import com.limechain.network.protocol.grandpa.messages.consensus.GrandpaConsensusMessageFormat;
 import com.limechain.network.protocol.warp.dto.BlockHeader;
 import com.limechain.network.protocol.warp.dto.ConsensusEngine;
 import com.limechain.network.protocol.warp.dto.DigestType;
@@ -52,6 +53,34 @@ void getBabeConsensusMessageWithoutSuchDigestInHeadersTest() {
         assertTrue(optResult.isEmpty());
     }
 
+    @Test
+    void getGrandpaConsensusMessageTest() {
+        HeaderDigest consensusDigest = new HeaderDigest();
+        consensusDigest.setId(ConsensusEngine.GRANDPA);
+        consensusDigest.setType(DigestType.CONSENSUS_MESSAGE);
+
+        // Create a consensus message with type GRANDPA_ON_DISABLED(3) and value equal to 0
+        var message = new byte[33];
+        message[0] = 3;
+        consensusDigest.setMessage(message);
+
+        HeaderDigest[] headerDigests = new HeaderDigest[] {consensusDigest};
+        var optResult = DigestHelper.getGrandpaConsensusMessage(headerDigests);
+
+        assertTrue(optResult.isPresent());
+
+        var result = optResult.get();
+        assertEquals(GrandpaConsensusMessageFormat.GRANDPA_ON_DISABLED, result.getFormat());
+        assertEquals(BigInteger.ZERO, result.getDisabledAuthority());
+        assertNull(result.getAuthorities());
+    }
+
+    @Test
+    void getGrandpaConsensusMessageWithoutSuchDigestInHeadersTest() {
+        var optResult = DigestHelper.getGrandpaConsensusMessage(new HeaderDigest[0]);
+        assertTrue(optResult.isEmpty());
+    }
+
     @Test
     void getBabePreRuntimeDigestForPrimarySlotTest() {
         HeaderDigest consensusDigest = new HeaderDigest();