Add listAccounts command

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

@@ -17,6 +17,7 @@ public class Commands {
         addCommand(new JoinGroupCommand());
         addCommand(new JsonRpcDispatcherCommand());
         addCommand(new LinkCommand());
+        addCommand(new ListAccountsCommand());
         addCommand(new ListContactsCommand());
         addCommand(new ListDevicesCommand());
         addCommand(new ListGroupsCommand());

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

@@ -0,0 +1,41 @@
+package org.asamk.signal.commands;
+
+import net.sourceforge.argparse4j.inf.Namespace;
+import net.sourceforge.argparse4j.inf.Subparser;
+
+import org.asamk.signal.JsonWriter;
+import org.asamk.signal.OutputWriter;
+import org.asamk.signal.PlainTextWriter;
+import org.asamk.signal.commands.exceptions.CommandException;
+
+import java.util.stream.Collectors;
+
+public class ListAccountsCommand implements JsonRpcMultiLocalCommand {
+
+    @Override
+    public String getName() {
+        return "listAccounts";
+    }
+
+    @Override
+    public void attachToSubparser(final Subparser subparser) {
+        subparser.help("Show a list of registered accounts.");
+    }
+
+    @Override
+    public void handleCommand(
+            final Namespace ns, final SignalCreator c, final OutputWriter outputWriter
+    ) throws CommandException {
+        final var accountNumbers = c.getAccountNumbers();
+        if (outputWriter instanceof JsonWriter jsonWriter) {
+            final var jsonAccounts = accountNumbers.stream().map(JsonAccount::new).collect(Collectors.toList());
+            jsonWriter.write(jsonAccounts);
+        } else if (outputWriter instanceof PlainTextWriter plainTextWriter) {
+            for (final var number : accountNumbers) {
+                plainTextWriter.println("Number: {}", number);
+            }
+        }
+    }
+
+    private record JsonAccount(String number) {}
+}

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

@@ -119,7 +119,7 @@ public class SignalJsonRpcDispatcherHandler {
             final ObjectMapper objectMapper, final String method, ContainerNode<?> params
     ) throws JsonRpcException {
         var command = getCommand(method);
-        // TODO implement listAccounts, register, verify, link
+        // TODO implement register, verify, link
         if (c != null && command instanceof JsonRpcMultiCommand<?> jsonRpcCommand) {
             return runCommand(objectMapper, params, new MultiCommandRunnerImpl<>(c, jsonRpcCommand));
         }