Extract SignalJsonRpcDispatcherHandler

src/main/java/org/asamk/signal/jsonrpc/SignalJsonRpcDispatcherHandler.java

@@ -0,0 +1,138 @@
+package org.asamk.signal.jsonrpc;
+
+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 org.asamk.signal.JsonReceiveMessageHandler;
+import org.asamk.signal.JsonWriter;
+import org.asamk.signal.OutputWriter;
+import org.asamk.signal.commands.Commands;
+import org.asamk.signal.commands.JsonRpcCommand;
+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.manager.Manager;
+import org.asamk.signal.util.Util;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.function.Supplier;
+
+public class SignalJsonRpcDispatcherHandler {
+
+    private final static Logger logger = LoggerFactory.getLogger(SignalJsonRpcDispatcherHandler.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 Manager m;
+    private final JsonWriter outputWriter;
+    private final Supplier<String> lineSupplier;
+
+    public SignalJsonRpcDispatcherHandler(
+            final Manager m, final JsonWriter outputWriter, final Supplier<String> lineSupplier
+    ) {
+        this.m = m;
+        this.outputWriter = outputWriter;
+        this.lineSupplier = lineSupplier;
+    }
+
+    public void handleConnection() {
+        final var objectMapper = Util.createJsonObjectMapper();
+        final var jsonRpcSender = new JsonRpcSender(outputWriter);
+
+        final var receiveMessageHandler = new JsonReceiveMessageHandler(m,
+                s -> jsonRpcSender.sendRequest(JsonRpcRequest.forNotification("receive",
+                        objectMapper.valueToTree(s),
+                        null)));
+        try {
+            m.addReceiveHandler(receiveMessageHandler);
+
+            // Maybe this should be handled inside the Manager
+            while (!m.hasCaughtUpWithOldMessages()) {
+                try {
+                    synchronized (m) {
+                        m.wait();
+                    }
+                } catch (InterruptedException ignored) {
+                }
+            }
+
+            final var jsonRpcReader = new JsonRpcReader(jsonRpcSender, lineSupplier);
+            jsonRpcReader.readRequests((method, params) -> handleRequest(m, objectMapper, method, params),
+                    response -> logger.debug("Received unexpected response for id {}", response.getId()));
+        } finally {
+            m.removeReceiveHandler(receiveMessageHandler);
+        }
+    }
+
+    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);
+        if (!(command instanceof JsonRpcCommand)) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.METHOD_NOT_FOUND,
+                    "Method not implemented",
+                    null));
+        }
+
+        try {
+            parseParamsAndRunCommand(m, objectMapper, params, commandOutputWriter, (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 ? Map.of() : result[0];
+        return objectMapper.valueToTree(output);
+    }
+
+    private <T> void parseParamsAndRunCommand(
+            final Manager m,
+            final ObjectMapper objectMapper,
+            final TreeNode params,
+            final OutputWriter outputWriter,
+            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, outputWriter);
+    }
+}