// Copyright 2016 The Android Open Source Project
//
// This software is licensed under the terms of the GNU General Public
// License version 2, as published by the Free Software Foundation, and
// may be copied, distributed, and modified under those terms.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

#include "android/emulation/AdbHostListener.h"

#include "android/base/async/AsyncSocketServer.h"
#include "android/base/async/ThreadLooper.h"
#include "android/base/Log.h"
#include "android/base/sockets/ScopedSocket.h"
#include "android/base/sockets/SocketUtils.h"
#include "android/emulation/AdbHostServer.h"
#include "android/emulation/AdbTypes.h"

#include <memory>
#include <vector>

namespace android {
namespace emulation {

static bool systemSupportsIPv4() {
    int socket = base::socketCreateTcp4();
    if (socket < 0 && errno == EAFNOSUPPORT)
        return false;
    base::socketClose(socket);
    return true;
}

using android::base::AsyncSocketServer;
using android::base::ScopedSocket;

bool AdbHostListener::reset(int adbPort) {
    if (adbPort < 0) {
        mServer.reset();
    } else if (!mServer || adbPort != mServer->port()) {
        CHECK(adbPort < 65536);
        AsyncSocketServer::LoopbackMode mode =
            AsyncSocketServer::kIPv4AndOptionalIPv6;
        if (!systemSupportsIPv4()) {
            mode = AsyncSocketServer::kIPv6;
        }
        mServer = AsyncSocketServer::createTcpLoopbackServer(
                adbPort,
                [this](int port) { return this->onHostServerConnection(port); },
                mode,
                android::base::ThreadLooper::get());
        if (!mServer) {
            // This can happen when the emulator is probing for a free port
            // at startup, so don't print a warning here.
            return false;
        }
        // Don't start listening until startListening() is called.
    }
    return true;
}

void AdbHostListener::startListening() {
    if (mServer) {
        mServer->startListening();
    }
}

void AdbHostListener::stopListening() {
    if (mServer) {
        mServer->stopListening();
    }
}

void AdbHostListener::notifyServer() {
    if (mServer && mAdbClientPort > 0) {
        AdbHostServer::notify(mServer->port(), mAdbClientPort);
    }
}

bool AdbHostListener::onHostServerConnection(int socket) {
    mGuestAgent->onHostConnection(ScopedSocket(socket));
    return true;
}

}  // namespace emulation
}  // namespace android