Attach and send keys

package io.github.libtmux.examples;

import io.github.libtmux.Layout;
import io.github.libtmux.Pane;
import io.github.libtmux.Server;
import io.github.libtmux.ServerConfig;
import io.github.libtmux.ServerEndpoint;
import io.github.libtmux.Session;
import io.github.libtmux.Window;
import io.github.libtmux.exception.ServerUnavailableException;
import java.nio.file.Path;
import java.util.Optional;

/**
 * Lays out a session the way you would set one up by hand before starting work.
 *
 * <pre>{@code
 * java BuildAWorkspace.java /tmp/libtmux-java-dev/demo/s
 * }</pre>
 */
public final class BuildAWorkspace {

    private BuildAWorkspace() {}

    public static void main(String[] args) {
        System.out.println(run(Path.of(args.length > 0 ? args[0] : "/tmp/libtmux-java-dev/demo/s")));
    }

    /** Separated from {@code main} so the suite can run exactly what a reader runs. */
    public static String run(Path socket) {
        ServerConfig config = ServerConfig.builder()
                .endpoint(ServerEndpoint.socketPath(socket))
                .configFile(Path.of("/dev/null"))
                .build();

        // Closing a server closes this client. The tmux server, and the session, outlive the program
        // — which is the whole point of tmux and the reason nothing here kills it.
        try (Server server = Server.open(config)) {
            // One read decides and answers. An absent daemon means the name cannot be taken, so
            // that specific failure is the other way this resolves to "not found".
            Optional<Session> existing;
            try {
                existing = server.session("work");
            } catch (ServerUnavailableException absent) {
                existing = Optional.empty();
            }
            Session session = existing.orElseGet(() -> server.newSession("work"));

            Window editor = session.newWindow(window -> window.named("editor").detached());
            Pane shell = editor.split(split -> split.toRight());
            shell.sendLine("git status --short");

            editor.selectLayout(Layout.MAIN_VERTICAL);

            return "session " + session.name() + " has "
                    + session.refresh().windows().size() + " windows";
        }
    }
}