package hudson.cli;

import hudson.Extension;
import hudson.Util;
import hudson.model.Computer;
import hudson.remoting.Channel;
import hudson.remoting.Channel.Mode;
import hudson.remoting.ChannelBuilder;
import jenkins.AgentProtocol;
import jenkins.model.Jenkins;
import jenkins.slaves.NioChannelSelector;
import org.jenkinsci.Symbol;
import org.jenkinsci.remoting.nio.NioChannelHub;

import javax.inject.Inject;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;

/**
 * {@link AgentProtocol} that accepts connection from CLI clients.
 *
 * @author Kohsuke Kawaguchi
 * @since 1.467
 */
@Extension @Symbol("cli")
public class CliProtocol extends AgentProtocol {
    @Inject
    NioChannelSelector nio;

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean isOptIn() {
        return OPT_IN;
    }

    @Override
    public String getName() {
        return "CLI-connect";
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getDisplayName() {
        return "Jenkins CLI Protocol/1";
    }

    @Override
    public void handle(Socket socket) throws IOException, InterruptedException {
        new Handler(nio.getHub(),socket).run();
    }

    protected static class Handler {
        protected final NioChannelHub hub;
        protected final Socket socket;

        /**
         * @deprecated as of 1.559
         *      Use {@link #Handler(NioChannelHub, Socket)}
         */
        @Deprecated
        public Handler(Socket socket) {
            this(null,socket);
        }

        public Handler(NioChannelHub hub, Socket socket) {
            this.hub = hub;
            this.socket = socket;
        }

        public void run() throws IOException, InterruptedException {
            PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(),"UTF-8")),true);
            out.println("Welcome");
            runCli(new Connection(socket));
        }

        protected void runCli(Connection c) throws IOException, InterruptedException {
            ChannelBuilder cb;
            String name = "CLI channel from " + socket.getInetAddress();

            // Connection can contain cipher wrapper, which can't be NIO-ed.
//            if (hub!=null)
//                cb = hub.newChannelBuilder(name, Computer.threadPoolForRemoting);
//            else
                cb = new ChannelBuilder(name, Computer.threadPoolForRemoting);

            Channel channel = cb
                    .withMode(Mode.BINARY)
                    .withRestricted(true)
                    .withBaseLoader(Jenkins.getActiveInstance().pluginManager.uberClassLoader)
                    .build(new BufferedInputStream(c.in), new BufferedOutputStream(c.out));

            channel.setProperty(CliEntryPoint.class.getName(),new CliManagerImpl(channel));
            channel.join();
        }
    }

    /**
     * A/B test turning off this protocol by default.
     */
    private static final boolean OPT_IN;

    static {
        byte hash = Util.fromHexString(Jenkins.getInstance().getLegacyInstanceId())[0];
        OPT_IN = (hash % 10) == 0;
    }
}