Implement sendReceipt command

Fixes #305

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

@@ -30,6 +30,7 @@ public class Commands {
         addCommand(new SendCommand());
         addCommand(new SendContactsCommand());
         addCommand(new SendReactionCommand());
+        addCommand(new SendReceiptCommand());
         addCommand(new SendSyncRequestCommand());
         addCommand(new SendTypingCommand());
         addCommand(new SetPinCommand());

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

@@ -0,0 +1,56 @@
+package org.asamk.signal.commands;
+
+import net.sourceforge.argparse4j.inf.Namespace;
+import net.sourceforge.argparse4j.inf.Subparser;
+
+import org.asamk.signal.OutputWriter;
+import org.asamk.signal.commands.exceptions.CommandException;
+import org.asamk.signal.commands.exceptions.UserErrorException;
+import org.asamk.signal.manager.Manager;
+import org.whispersystems.signalservice.api.crypto.UntrustedIdentityException;
+import org.whispersystems.signalservice.api.util.InvalidNumberException;
+
+import java.io.IOException;
+
+public class SendReceiptCommand implements JsonRpcLocalCommand {
+
+    @Override
+    public String getName() {
+        return "sendReceipt";
+    }
+
+    @Override
+    public void attachToSubparser(final Subparser subparser) {
+        subparser.help("Send a read or viewed receipt to a previously received message.");
+        subparser.addArgument("recipient").help("Specify the sender's phone number.").required(true);
+        subparser.addArgument("-t", "--target-timestamp")
+                .type(long.class)
+                .nargs("+")
+                .help("Specify the timestamp of the messages for which a receipt should be sent.");
+        subparser.addArgument("--type").help("Specify the receipt type.").choices("read", "viewed").setDefault("read");
+    }
+
+    @Override
+    public void handleCommand(
+            final Namespace ns, final Manager m, final OutputWriter outputWriter
+    ) throws CommandException {
+        final var recipient = ns.getString("recipient");
+
+        final var targetTimestamps = ns.<Long>getList("target-timestamp");
+        final var type = ns.getString("type");
+
+        try {
+            if ("read".equals(type)) {
+                m.sendReadReceipt(recipient, targetTimestamps);
+            } else if ("viewed".equals(type)) {
+                m.sendViewedReceipt(recipient, targetTimestamps);
+            } else {
+                throw new UserErrorException("Unknown receipt type: " + type);
+            }
+        } catch (IOException | UntrustedIdentityException e) {
+            throw new UserErrorException("Failed to send message: " + e.getMessage());
+        } catch (InvalidNumberException e) {
+            throw new UserErrorException("Invalid number: " + e.getMessage());
+        }
+    }
+}