Split commands into separate classes

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

@@ -0,0 +1,50 @@
+package org.asamk.signal.commands;
+
+import net.sourceforge.argparse4j.inf.Namespace;
+import net.sourceforge.argparse4j.inf.Subparser;
+import org.asamk.signal.UserAlreadyExists;
+import org.asamk.signal.manager.Manager;
+import org.whispersystems.libsignal.InvalidKeyException;
+
+import java.io.IOException;
+import java.util.concurrent.TimeoutException;
+
+import static org.asamk.signal.util.ErrorUtils.handleAssertionError;
+
+public class LinkCommand implements LocalCommand {
+
+    @Override
+    public void attachToSubparser(final Subparser subparser) {
+        subparser.addArgument("-n", "--name")
+                .help("Specify a name to describe this new device.");
+    }
+
+    @Override
+    public int handleCommand(final Namespace ns, final Manager m) {
+        String deviceName = ns.getString("name");
+        if (deviceName == null) {
+            deviceName = "cli";
+        }
+        try {
+            System.out.println(m.getDeviceLinkUri());
+            m.finishDeviceLink(deviceName);
+            System.out.println("Associated with: " + m.getUsername());
+        } catch (TimeoutException e) {
+            System.err.println("Link request timed out, please try again.");
+            return 3;
+        } catch (IOException e) {
+            System.err.println("Link request error: " + e.getMessage());
+            return 3;
+        } catch (AssertionError e) {
+            handleAssertionError(e);
+            return 1;
+        } catch (InvalidKeyException e) {
+            e.printStackTrace();
+            return 2;
+        } catch (UserAlreadyExists e) {
+            System.err.println("The user " + e.getUsername() + " already exists\nDelete \"" + e.getFileName() + "\" before trying again.");
+            return 1;
+        }
+        return 0;
+    }
+}