/***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2007 Ola Bini <ola@ologix.com>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
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package org.jruby.ext.socket;

import org.jruby.Ruby;
import org.jruby.RubyBasicObject;
import org.jruby.RubyClass;
import org.jruby.RubyFixnum;
import org.jruby.RubyString;
import org.jruby.RubyThread;
import org.jruby.anno.JRubyClass;
import org.jruby.anno.JRubyMethod;
import org.jruby.api.Access;
import org.jruby.runtime.Block;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.Visibility;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.util.io.FilenoUtil;
import org.jruby.util.io.SelectorFactory;

import java.io.IOException;
import java.net.BindException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.channels.spi.SelectorProvider;

import static org.jruby.api.Convert.asFixnum;
import static org.jruby.api.Convert.asSymbol;
import static org.jruby.api.Define.defineClass;
import static org.jruby.api.Error.argumentError;
import static org.jruby.api.Error.typeError;

@JRubyClass(name="TCPServer", parent="TCPSocket")
public class RubyTCPServer extends RubyTCPSocket {
    static void createTCPServer(ThreadContext context, RubyClass TCPSocket) {
        defineClass(context, "TCPServer", TCPSocket, RubyTCPServer::new).
                defineMethods(context, RubyTCPServer.class);
    }

    public RubyTCPServer(Ruby runtime, RubyClass type) {
        super(runtime, type);
    }

    @JRubyMethod(name = "initialize", required = 1, optional = 1, checkArity = false, visibility = Visibility.PRIVATE)
    public IRubyObject initialize(ThreadContext context, IRubyObject[] args) {
        Ruby runtime = context.runtime;
        IRubyObject _host;
        IRubyObject _port = null;
        String host = "0.0.0.0";

        switch (args.length) {
            case 2:
                _host = args[0];
                _port = args[1];

                if (_host.isNil()) break;
                if (_host instanceof RubyFixnum) throw typeError(context, _host, "String");

                RubyString hostString = _host.convertToString();
                if (!hostString.isEmpty()) host = hostString.toString();

                break;
            case 1:
                _host = context.nil;
                _port = args[0];
                break;
            default:
                throw argumentError(context, args.length, 1, 2);
        }

        int port = SocketUtils.getPortFrom(context, _port);

        ServerSocketChannel ssc = null;
        boolean success = false;

        try {
            InetAddress addr = InetAddress.getByName(host);

            ssc = ServerSocketChannel.open();
            ssc.socket().setReuseAddress(true);

            InetSocketAddress socket_address = new InetSocketAddress(addr, port);

            ssc.socket().bind(socket_address);

            initSocket(newChannelFD(runtime, ssc));

            success = true;
        } catch (UnknownHostException e) {
            throw SocketUtils.sockerr(runtime, "initialize: name or service not known");
        } catch (BindException e) {
            throw runtime.newErrnoFromBindException(e, bindContextMessage(context, _host, port));
        } catch (SocketException e) {
            String msg = e.getMessage();

            throw msg.contains("Permission denied") ?
                    runtime.newErrnoEACCESError("bind(2)") :
                    SocketUtils.sockerr(runtime, "initialize: name or service not known");
        } catch (IOException e) {
            throw runtime.newIOErrorFromException(e);
        } catch (IllegalArgumentException iae) {
            throw SocketUtils.sockerr(runtime, iae.getMessage());
        } finally {
            if (!success && ssc != null) {
                try { ssc.close(); } catch (IOException ioe) {}
            }
        }

        return this;
    }

    @JRubyMethod(name = "accept")
    public IRubyObject accept(ThreadContext context) {
        RubyTCPSocket socket = new RubyTCPSocket(context.runtime, Access.getClass(context, "TCPSocket"));

        try {
            RubyThread thread = context.getThread();

            while (true) {
                boolean ready = thread.select(this, SelectionKey.OP_ACCEPT);

                if (!ready) {
                    // we were woken up without being selected...poll for thread events and go back to sleep
                    context.pollThreadEvents();

                } else {
                    SocketChannel connected = getServerSocketChannel().accept();
                    if (connected == null) continue;

                    connected.finishConnect();

                    // Force the client socket to be blocking
                    synchronized (connected.blockingLock()) {
                        connected.configureBlocking(false);
                        connected.configureBlocking(true);
                    }

                    // otherwise one key has been selected (ours) so we get the channel and hand it off
                    socket.initSocket(newChannelFD(context.runtime, connected));

                    return socket;
                }
            }

        } catch(IOException e) {
            throw context.runtime.newIOErrorFromException(e);
        }
    }

    @JRubyMethod(name = "accept_nonblock")
    public IRubyObject accept_nonblock(ThreadContext context) {
        return accept_nonblock(context, context.runtime, true);
    }

    @JRubyMethod(name = "accept_nonblock")
    public IRubyObject accept_nonblock(ThreadContext context, IRubyObject opts) {
        return accept_nonblock(context, context.runtime, extractExceptionArg(context, opts));
    }

    public IRubyObject accept_nonblock(ThreadContext context, Ruby runtime, boolean ex) {
        RubyTCPSocket socket = new RubyTCPSocket(runtime, Access.getClass(context, "TCPSocket"));
        Selector selector = null;
        ServerSocketChannel ssc = getServerSocketChannel();

        synchronized (ssc.blockingLock()) {
            boolean oldBlocking = ssc.isBlocking();

            try {
                ssc.configureBlocking(false);
                selector = SelectorFactory.openWithRetryFrom(runtime, SelectorProvider.provider());

                boolean ready = context.getThread().select(this, SelectionKey.OP_ACCEPT, 0);

                if (!ready) {
                    // no connection immediately accepted, let them try again

                    if (ex) {
                        throw runtime.newErrnoEAGAINReadableError("Resource temporarily unavailable");
                    }

                    return asSymbol(context, "wait_readable");

                } else {
                    // otherwise one key has been selected (ours) so we get the channel and hand it off
                    socket.initSocket(newChannelFD(runtime, ssc.accept()));

                    return socket;
                }

            } catch(IOException e) {
                throw runtime.newIOErrorFromException(e);

            } finally {
                try {
                    if (selector != null) selector.close();
                } catch (Exception e) {
                }
                try {ssc.configureBlocking(oldBlocking);} catch (IOException ioe) {}

            }
        }
    }

    @JRubyMethod(name = "sysaccept")
    public IRubyObject sysaccept(ThreadContext context) {
        try {
            RubyThread thread = context.getThread();

            while (true) {
                boolean ready = thread.select(this, SelectionKey.OP_ACCEPT);

                if (!ready) {
                    // we were woken up without being selected...poll for thread events and go back to sleep
                    context.pollThreadEvents();

                } else {
                    SocketChannel connected = getServerSocketChannel().accept();
                    if (connected == null) continue;

                    connected.finishConnect();

                    return asFixnum(context, FilenoUtil.filenoFrom(connected));
                }
            }

        } catch(IOException e) {
            throw context.runtime.newIOErrorFromException(e);
        }
    }

    @JRubyMethod(name = "listen")
    public IRubyObject listen(ThreadContext context, IRubyObject backlog) {
        return RubyFixnum.zero(context.runtime);
    }

    @JRubyMethod(name = "peeraddr", rest = true)
    public IRubyObject peeraddr(ThreadContext context, IRubyObject[] args) {
        throw context.runtime.newNotImplementedError("not supported");
    }

    @JRubyMethod(name = "getpeername", rest = true)
    public IRubyObject getpeername(ThreadContext context, IRubyObject[] args) {
        throw context.runtime.newNotImplementedError("not supported");
    }

    @JRubyMethod(rest = true, meta = true)
    public static IRubyObject open(ThreadContext context, IRubyObject recv, IRubyObject[] args, Block block) {
        IRubyObject tcpServer = recv.callMethod(context, "new", args);

        if (!block.isGiven()) return tcpServer;

        try {
            return block.yield(context, tcpServer);
        } finally {
            tcpServer.callMethod(context, "close");
        }
    }

    public ServerSocketChannel getServerSocketChannel() {
        return (ServerSocketChannel)getChannel();
    }

    @Override
    public IRubyObject shutdown(ThreadContext context, IRubyObject[] args) {
        // act like a platform that does not support shutdown for server sockets
        throw context.runtime.newErrnoENOTCONNError();
    }

    @Override
    public IRubyObject gets(ThreadContext context) {
        throw context.runtime.newErrnoENOTCONNError();
    }

    @Override
    public IRubyObject gets(ThreadContext context, IRubyObject sep) {
        throw context.runtime.newErrnoENOTCONNError();
    }

    @Override
    public IRubyObject gets(ThreadContext context, IRubyObject sep, IRubyObject limit) {
        throw context.runtime.newErrnoENOTCONNError();
    }
}
