Implement jsonRpc command

Co-authored-by: technillogue <technillogue@gmail.com>

Closes #668

src/main/java/org/asamk/signal/commands/JsonRpcDispatcherCommand.java

@@ -0,0 +1,174 @@
+package org.asamk.signal.commands;
+
+import com.fasterxml.jackson.core.TreeNode;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ContainerNode;
+
+import net.sourceforge.argparse4j.impl.Arguments;
+import net.sourceforge.argparse4j.inf.Namespace;
+import net.sourceforge.argparse4j.inf.Subparser;
+
+import org.asamk.signal.JsonReceiveMessageHandler;
+import org.asamk.signal.JsonWriter;
+import org.asamk.signal.OutputType;
+import org.asamk.signal.OutputWriter;
+import org.asamk.signal.commands.exceptions.CommandException;
+import org.asamk.signal.commands.exceptions.IOErrorException;
+import org.asamk.signal.commands.exceptions.UntrustedKeyErrorException;
+import org.asamk.signal.commands.exceptions.UserErrorException;
+import org.asamk.signal.jsonrpc.JsonRpcException;
+import org.asamk.signal.jsonrpc.JsonRpcReader;
+import org.asamk.signal.jsonrpc.JsonRpcRequest;
+import org.asamk.signal.jsonrpc.JsonRpcResponse;
+import org.asamk.signal.jsonrpc.JsonRpcSender;
+import org.asamk.signal.manager.Manager;
+import org.asamk.signal.util.Util;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+
+public class JsonRpcDispatcherCommand implements LocalCommand {
+
+    private final static Logger logger = LoggerFactory.getLogger(JsonRpcDispatcherCommand.class);
+
+    private static final int USER_ERROR = -1;
+    private static final int IO_ERROR = -3;
+    private static final int UNTRUSTED_KEY_ERROR = -4;
+
+    private final OutputWriter outputWriter;
+
+    public static void attachToSubparser(final Subparser subparser) {
+        subparser.help("Take commands from standard input as line-delimited JSON RPC while receiving messages.");
+        subparser.addArgument("--ignore-attachments")
+                .help("Don’t download attachments of received messages.")
+                .action(Arguments.storeTrue());
+    }
+
+    public JsonRpcDispatcherCommand(final OutputWriter outputWriter) {
+        this.outputWriter = outputWriter;
+    }
+
+    @Override
+    public Set<OutputType> getSupportedOutputTypes() {
+        return Set.of(OutputType.JSON);
+    }
+
+    @Override
+    public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
+        final boolean ignoreAttachments = ns.getBoolean("ignore-attachments");
+
+        final var objectMapper = Util.createJsonObjectMapper();
+        final var jsonRpcSender = new JsonRpcSender((JsonWriter) outputWriter);
+
+        final var receiveThread = receiveMessages(s -> jsonRpcSender.sendRequest(JsonRpcRequest.forNotification(
+                "receive",
+                objectMapper.valueToTree(s),
+                null)), m, ignoreAttachments);
+
+        final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+
+        final var jsonRpcReader = new JsonRpcReader(jsonRpcSender, () -> {
+            try {
+                return reader.readLine();
+            } catch (IOException e) {
+                throw new AssertionError(e);
+            }
+        });
+        jsonRpcReader.readRequests((method, params) -> handleRequest(m, objectMapper, method, params),
+                response -> logger.debug("Received unexpected response for id {}", response.getId()));
+
+        receiveThread.interrupt();
+        try {
+            receiveThread.join();
+        } catch (InterruptedException ignored) {
+        }
+    }
+
+    private JsonNode handleRequest(
+            final Manager m, final ObjectMapper objectMapper, final String method, ContainerNode<?> params
+    ) throws JsonRpcException {
+        final Object[] result = {null};
+        final JsonWriter commandOutputWriter = s -> {
+            if (result[0] != null) {
+                throw new AssertionError("Command may only write one json result");
+            }
+
+            result[0] = s;
+        };
+
+        var command = Commands.getCommand(method, commandOutputWriter);
+        if (!(command instanceof JsonRpcCommand)) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.METHOD_NOT_FOUND,
+                    "Method not implemented",
+                    null));
+        }
+
+        try {
+            parseParamsAndRunCommand(m, objectMapper, params, (JsonRpcCommand<?>) command);
+        } catch (JsonMappingException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                    e.getMessage(),
+                    null));
+        } catch (UserErrorException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(USER_ERROR, e.getMessage(), null));
+        } catch (IOErrorException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(IO_ERROR, e.getMessage(), null));
+        } catch (UntrustedKeyErrorException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(UNTRUSTED_KEY_ERROR, e.getMessage(), null));
+        } catch (Throwable e) {
+            logger.error("Command execution failed", e);
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.INTERNAL_ERROR,
+                    e.getMessage(),
+                    null));
+        }
+
+        Object output = result[0] == null ? new Object() : result[0];
+        return objectMapper.valueToTree(output);
+    }
+
+    private <T> void parseParamsAndRunCommand(
+            final Manager m, final ObjectMapper objectMapper, final TreeNode params, final JsonRpcCommand<T> command
+    ) throws CommandException, JsonMappingException {
+        T requestParams = null;
+        final var requestType = command.getRequestType();
+        if (params != null && requestType != null) {
+            try {
+                requestParams = objectMapper.readValue(objectMapper.treeAsTokens(params), requestType);
+            } catch (JsonMappingException e) {
+                throw e;
+            } catch (IOException e) {
+                throw new AssertionError(e);
+            }
+        }
+        command.handleCommand(requestParams, m);
+    }
+
+    private Thread receiveMessages(
+            JsonWriter jsonWriter, Manager m, boolean ignoreAttachments
+    ) {
+        final var thread = new Thread(() -> {
+            while (!Thread.interrupted()) {
+                try {
+                    final var receiveMessageHandler = new JsonReceiveMessageHandler(m, jsonWriter);
+                    m.receiveMessages(1, TimeUnit.HOURS, false, ignoreAttachments, receiveMessageHandler);
+                    break;
+                } catch (IOException e) {
+                    logger.warn("Receiving messages failed, retrying", e);
+                } catch (InterruptedException e) {
+                    break;
+                }
+            }
+        });
+
+        thread.start();
+
+        return thread;
+    }
+}