Implement jsonRpc command

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

Closes #668

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

@@ -0,0 +1,72 @@
+package org.asamk.signal.commands;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import net.sourceforge.argparse4j.inf.Namespace;
+
+import org.asamk.signal.OutputType;
+import org.asamk.signal.commands.exceptions.CommandException;
+import org.asamk.signal.manager.Manager;
+import org.asamk.signal.util.Util;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public interface JsonRpcLocalCommand extends JsonRpcCommand<Map<String, Object>> {
+
+    void handleCommand(Namespace ns, Manager m) throws CommandException;
+
+    default TypeReference<Map<String, Object>> getRequestType() {
+        return new TypeReference<>() {
+        };
+    }
+
+    default void handleCommand(Map<String, Object> request, Manager m) throws CommandException {
+        Namespace commandNamespace = new JsonRpcNamespace(request == null ? Map.of() : request);
+        handleCommand(commandNamespace, m);
+    }
+
+    default Set<OutputType> getSupportedOutputTypes() {
+        return Set.of(OutputType.PLAIN_TEXT, OutputType.JSON);
+    }
+
+    /**
+     * Namepace implementation, that defaults booleans to false and converts camel case keys to dashed strings
+     */
+    final class JsonRpcNamespace extends Namespace {
+
+        public JsonRpcNamespace(final Map<String, Object> attrs) {
+            super(attrs);
+        }
+
+        public <T> T get(String dest) {
+            final T value = super.get(dest);
+            if (value != null) {
+                return value;
+            }
+
+            final var camelCaseString = Util.dashSeparatedToCamelCaseString(dest);
+            return super.get(camelCaseString);
+        }
+
+        @Override
+        public <E> List<E> getList(final String dest) {
+            final List<E> value = super.getList(dest);
+            if (value != null) {
+                return value;
+            }
+
+            return super.getList(dest + "s");
+        }
+
+        @Override
+        public Boolean getBoolean(String dest) {
+            Boolean maybeGotten = this.get(dest);
+            if (maybeGotten == null) {
+                maybeGotten = false;
+            }
+            return maybeGotten;
+        }
+    }
+}