Add Bitcoin Core version & health check to RpcService

Make a 'getnetworkinfo' RPC call to bitcoind immediately upon startup,
to check that the node is up (and throw a ConnectException to ensure
that the user is presented with an appropriate warning popup otherwise).
Log a warning if the node version is outside the 0.18.0 - 0.20.1 range.

Additionally, call 'getbestblockhash' to check that the chain tip is not
stale (> 6 hours old). As part of this, make sure the 'getblock' RPC
call works correctly with verbosity < 2, by fixing JSON deserialisation
of the response when the block or txs are in summary (hex string) form.

(These version & health checks are almost identical to the ones done by
the original btcd-cli4j library during RPC client startup.)

core/src/main/java/bisq/core/dao/node/full/RpcService.java

@@ -26,6 +26,8 @@ import bisq.core.dao.state.model.blockchain.ScriptType;
 import bisq.core.dao.state.model.blockchain.TxInput;
 import bisq.core.user.Preferences;
 
+import bisq.network.http.HttpException;
+
 import bisq.common.UserThread;
 import bisq.common.config.Config;
 import bisq.common.handlers.ResultHandler;
@@ -38,17 +40,24 @@ import com.google.inject.Inject;
 import javax.inject.Named;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Range;
+import com.google.common.primitives.Chars;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
 
+import java.io.IOException;
+
 import java.math.BigDecimal;
 
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
@@ -69,6 +78,7 @@ public class RpcService {
     private static final Set<String> BSQ_TXS_DISALLOWING_SEGWIT_PUB_KEYS = Set.of(
             "d1f45e55be6101b1b75e6bf9fc5e5341c6ab420647be7555863bbbddd84e92f3" // in mainnet block 660384, 2020-12-07
     );
+    private static final Range<Integer> SUPPORTED_NODE_VERSION_RANGE = Range.closedOpen(180000, 210000);
 
     private final String rpcUser;
     private final String rpcPassword;
@@ -143,12 +153,13 @@ public class RpcService {
                         .rpcUser(rpcUser)
                         .rpcPassword(rpcPassword)
                         .build();
+                checkNodeVersionAndHealth();
+
                 daemon = new BitcoindDaemon(rpcBlockHost, rpcBlockPort, throwable -> {
                     log.error(throwable.toString());
                     throwable.printStackTrace();
                     UserThread.execute(() -> errorHandler.accept(new RpcException(throwable)));
                 });
-                // TODO: Client should ping or request network info from bitcoind to make sure it is up.
 
                 log.info("Setup took {} ms", System.currentTimeMillis() - startTs);
             } catch (Throwable e) {
@@ -170,6 +181,35 @@ public class RpcService {
         }, MoreExecutors.directExecutor());
     }
 
+    private String decodeNodeVersion(Integer encodedVersion) {
+        var paddedEncodedVersion = Strings.padStart(encodedVersion.toString(), 8, '0');
+
+        return Lists.partition(Chars.asList(paddedEncodedVersion.toCharArray()), 2).stream()
+                .map(chars -> new String(Chars.toArray(chars)).replaceAll("^0", ""))
+                .collect(Collectors.joining("."))
+                .replaceAll("\\.0$", "");
+    }
+
+    private void checkNodeVersionAndHealth() throws IOException, HttpException {
+        var networkInfo = client.getNetworkInfo();
+        var nodeVersion = decodeNodeVersion(networkInfo.getVersion());
+
+        if (SUPPORTED_NODE_VERSION_RANGE.contains(networkInfo.getVersion())) {
+            log.info("Got Bitcoin Core version: {}", nodeVersion);
+        } else {
+            log.warn("Server version mismatch - client optimized for '[{} .. {})', node responded with '{}'",
+                    decodeNodeVersion(SUPPORTED_NODE_VERSION_RANGE.lowerEndpoint()),
+                    decodeNodeVersion(SUPPORTED_NODE_VERSION_RANGE.upperEndpoint()), nodeVersion);
+        }
+
+        var bestRawBlock = client.getBlock(client.getBestBlockHash(), 1);
+        long currentTime = System.currentTimeMillis() / 1000;
+        if ((currentTime - bestRawBlock.getTime()) > TimeUnit.HOURS.toSeconds(6)) {
+            log.warn("Last available block was mined >{} hours ago; please check your network connection",
+                    ((currentTime - bestRawBlock.getTime()) / 3600));
+        }
+    }
+
     void addNewDtoBlockHandler(Consumer<RawBlock> dtoBlockHandler,
                                Consumer<Throwable> errorHandler) {
         daemon.setBlockListener(blockHash -> {

core/src/main/java/bisq/core/dao/node/full/rpc/dto/RawBlock.java

@@ -17,14 +17,18 @@
 
 package bisq.core.dao.node.full.rpc.dto;
 
+import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+import com.fasterxml.jackson.annotation.JsonValue;
 
 import java.util.List;
 
 import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
 import lombok.NoArgsConstructor;
 
 @Data
@@ -63,4 +67,18 @@ public class RawBlock {
     private String previousBlockHash;
     @JsonProperty("nextblockhash")
     private String nextBlockHash;
+
+    @JsonCreator
+    public static Summarized summarized(String hex) {
+        var result = new Summarized();
+        result.setHex(hex);
+        return result;
+    }
+
+    @Data
+    @EqualsAndHashCode(callSuper = true)
+    public static class Summarized extends RawBlock {
+        @Getter(onMethod_ = @JsonValue)
+        private String hex;
+    }
 }

core/src/main/java/bisq/core/dao/node/full/rpc/dto/RawTransaction.java

@@ -17,10 +17,12 @@
 
 package bisq.core.dao.node.full.rpc.dto;
 
+import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+import com.fasterxml.jackson.annotation.JsonValue;
 
 import java.util.List;
 
@@ -56,4 +58,19 @@ public class RawTransaction {
     private Long blockTime;
     private Long time;
     private String hex;
+
+    @JsonCreator
+    public static Summarized summarized(String hex) {
+        var result = new Summarized();
+        result.setHex(hex);
+        return result;
+    }
+
+    public static class Summarized extends RawTransaction {
+        @Override
+        @JsonValue
+        public String getHex() {
+            return super.getHex();
+        }
+    }
 }

core/src/test/java/bisq/core/dao/node/full/rpc/BitcoindClientTest.java

@@ -17,6 +17,9 @@
 
 package bisq.core.dao.node.full.rpc;
 
+import bisq.core.dao.node.full.rpc.dto.RawBlock;
+import bisq.core.dao.node.full.rpc.dto.RawTransaction;
+
 import bisq.network.http.HttpException;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -36,7 +39,6 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
@@ -149,13 +151,11 @@ public class BitcoindClientTest {
     }
 
     @Test
-    @Ignore // TODO: Allow serialization/deserialization between RawBlock (with special field) and Json string
     public void testGetBlock_verbosity_0() throws Exception {
         doTestGetBlock(0, "\"" + TEST_BLOCK_VERBOSITY_0 + "\"");
     }
 
     @Test
-    @Ignore // TODO: Allow serialization/deserialization between RawTransaction (with special field) and Json string
     public void testGetBlock_verbosity_1() throws Exception {
         doTestGetBlock(1, TEST_BLOCK_VERBOSITY_1);
     }
@@ -173,6 +173,10 @@ public class BitcoindClientTest {
         var block = client.getBlock(TEST_BLOCK_HASH, verbosity);
         var blockJsonRoundTripped = new ObjectMapper().writeValueAsString(block);
 
+        assertEquals(verbosity == 0, block instanceof RawBlock.Summarized);
+        assertEquals(verbosity == 1, block.getTx() != null &&
+                block.getTx().stream().allMatch(tx -> tx instanceof RawTransaction.Summarized));
+
         assertEquals(blockJson, blockJsonRoundTripped);
         assertEquals(expectedRequest, mockOutputStream.toString(UTF_8));
     }