/*
 * barrier -- mouse and keyboard sharing utility
 * Copyright (C) 2012-2016 Symless Ltd.
 * Copyright (C) 2002 Chris Schoeneman
 *
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file LICENSE that should have accompanied this file.
 *
 * This package 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "server/ClientProxy1_0.h"

#include "barrier/ProtocolUtil.h"
#include "barrier/XBarrier.h"
#include "io/IStream.h"
#include "base/Log.h"
#include "base/IEventQueue.h"
#include "base/TMethodEventJob.h"

#include <cstring>

//
// ClientProxy1_0
//

ClientProxy1_0::ClientProxy1_0(const std::string& name, barrier::IStream* stream,
                               IEventQueue* events) :
    ClientProxy(name, stream),
    m_heartbeatTimer(NULL),
    m_parser(&ClientProxy1_0::parseHandshakeMessage),
    m_events(events)
{
    // install event handlers
    m_events->adoptHandler(m_events->forIStream().inputReady(),
                            stream->getEventTarget(),
                            new TMethodEventJob<ClientProxy1_0>(this,
                                &ClientProxy1_0::handleData, NULL));
    m_events->adoptHandler(m_events->forIStream().outputError(),
                            stream->getEventTarget(),
                            new TMethodEventJob<ClientProxy1_0>(this,
                                &ClientProxy1_0::handleWriteError, NULL));
    m_events->adoptHandler(m_events->forIStream().inputShutdown(),
                            stream->getEventTarget(),
                            new TMethodEventJob<ClientProxy1_0>(this,
                                &ClientProxy1_0::handleDisconnect, NULL));
    m_events->adoptHandler(m_events->forIStream().inputFormatError(),
                           stream->getEventTarget(),
                           new TMethodEventJob<ClientProxy1_0>(this,
                                &ClientProxy1_0::handleDisconnect, NULL));
    m_events->adoptHandler(m_events->forIStream().outputShutdown(),
                            stream->getEventTarget(),
                            new TMethodEventJob<ClientProxy1_0>(this,
                                &ClientProxy1_0::handleWriteError, NULL));
    m_events->adoptHandler(Event::kTimer, this,
                            new TMethodEventJob<ClientProxy1_0>(this,
                                &ClientProxy1_0::handleFlatline, NULL));

    setHeartbeatRate(kHeartRate, kHeartRate * kHeartBeatsUntilDeath);

    LOG((CLOG_DEBUG1 "querying client \"%s\" info", getName().c_str()));
    ProtocolUtil::writef(getStream(), kMsgQInfo);
}

ClientProxy1_0::~ClientProxy1_0()
{
    removeHandlers();
}

void
ClientProxy1_0::disconnect()
{
    removeHandlers();
    getStream()->close();
    m_events->addEvent(Event(m_events->forClientProxy().disconnected(), getEventTarget()));
}

void
ClientProxy1_0::removeHandlers()
{
    // uninstall event handlers
    m_events->removeHandler(m_events->forIStream().inputReady(),
                            getStream()->getEventTarget());
    m_events->removeHandler(m_events->forIStream().outputError(),
                            getStream()->getEventTarget());
    m_events->removeHandler(m_events->forIStream().inputShutdown(),
                            getStream()->getEventTarget());
    m_events->removeHandler(m_events->forIStream().outputShutdown(),
                            getStream()->getEventTarget());
    m_events->removeHandler(m_events->forIStream().inputFormatError(),
                            getStream()->getEventTarget());
    m_events->removeHandler(Event::kTimer, this);

    // remove timer
    removeHeartbeatTimer();
}

void
ClientProxy1_0::addHeartbeatTimer()
{
    if (m_heartbeatAlarm > 0.0) {
        m_heartbeatTimer = m_events->newOneShotTimer(m_heartbeatAlarm, this);
    }
}

void
ClientProxy1_0::removeHeartbeatTimer()
{
    if (m_heartbeatTimer != NULL) {
        m_events->deleteTimer(m_heartbeatTimer);
        m_heartbeatTimer = NULL;
    }
}

void
ClientProxy1_0::resetHeartbeatTimer()
{
    // reset the alarm
    removeHeartbeatTimer();
    addHeartbeatTimer();
}

void
ClientProxy1_0::resetHeartbeatRate()
{
    setHeartbeatRate(kHeartRate, kHeartRate * kHeartBeatsUntilDeath);
}

void
ClientProxy1_0::setHeartbeatRate(double, double alarm)
{
    m_heartbeatAlarm = alarm;
}

void
ClientProxy1_0::handleData(const Event&, void*)
{
    // handle messages until there are no more.  first read message code.
    UInt8 code[4];
    UInt32 n = getStream()->read(code, 4);
    while (n != 0) {
        // verify we got an entire code
        if (n != 4) {
            LOG((CLOG_ERR "incomplete message from \"%s\": %d bytes", getName().c_str(), n));
            disconnect();
            return;
        }

        // parse message
        try {
            LOG((CLOG_DEBUG2 "msg from \"%s\": %c%c%c%c", getName().c_str(), code[0], code[1], code[2], code[3]));
            if (!(this->*m_parser)(code)) {
                LOG((CLOG_ERR "invalid message from client \"%s\": %c%c%c%c", getName().c_str(), code[0], code[1], code[2], code[3]));
                disconnect();
                return;
            }
        } catch (const XBadClient& e) {
            // TODO: disconnect handling is currently dispersed across both parseMessage() and
            // handleData() functions, we should collect that to a single place

            LOG((CLOG_ERR "protocol error from client: %s", e.what()));
            disconnect();
            return;
        }

        // next message
        n = getStream()->read(code, 4);
    }

    // restart heartbeat timer
    resetHeartbeatTimer();
}

bool
ClientProxy1_0::parseHandshakeMessage(const UInt8* code)
{
    if (memcmp(code, kMsgCNoop, 4) == 0) {
        // discard no-ops
        LOG((CLOG_DEBUG2 "no-op from", getName().c_str()));
        return true;
    }
    else if (memcmp(code, kMsgDInfo, 4) == 0) {
        // future messages get parsed by parseMessage
        // NOTE: we're taking address of virtual function here,
        // not ClientProxy1_0 implementation of it.
        m_parser = &ClientProxy1_0::parseMessage;
        if (recvInfo()) {
            m_events->addEvent(Event(m_events->forClientProxy().ready(), getEventTarget()));
            addHeartbeatTimer();
            return true;
        }
    }
    return false;
}

bool
ClientProxy1_0::parseMessage(const UInt8* code)
{
    if (memcmp(code, kMsgDInfo, 4) == 0) {
        if (recvInfo()) {
            m_events->addEvent(
                            Event(m_events->forIScreen().shapeChanged(), getEventTarget()));
            return true;
        }
        return false;
    }
    else if (memcmp(code, kMsgCNoop, 4) == 0) {
        // discard no-ops
        LOG((CLOG_DEBUG2 "no-op from", getName().c_str()));
        return true;
    }
    else if (memcmp(code, kMsgCClipboard, 4) == 0) {
        return recvGrabClipboard();
    }
    else if (memcmp(code, kMsgDClipboard, 4) == 0) {
        return recvClipboard();
    }
    return false;
}

void
ClientProxy1_0::handleDisconnect(const Event&, void*)
{
    LOG((CLOG_NOTE "client \"%s\" has disconnected", getName().c_str()));
    disconnect();
}

void
ClientProxy1_0::handleWriteError(const Event&, void*)
{
    LOG((CLOG_WARN "error writing to client \"%s\"", getName().c_str()));
    disconnect();
}

void
ClientProxy1_0::handleFlatline(const Event&, void*)
{
    // didn't get a heartbeat fast enough.  assume client is dead.
    LOG((CLOG_NOTE "client \"%s\" is dead", getName().c_str()));
    disconnect();
}

bool
ClientProxy1_0::getClipboard(ClipboardID id, IClipboard* clipboard) const
{
    Clipboard::copy(clipboard, &m_clipboard[id].m_clipboard);
    return true;
}

void
ClientProxy1_0::getShape(SInt32& x, SInt32& y, SInt32& w, SInt32& h) const
{
    x = m_info.m_x;
    y = m_info.m_y;
    w = m_info.m_w;
    h = m_info.m_h;
}

void
ClientProxy1_0::getCursorPos(SInt32& x, SInt32& y) const
{
    // note -- this returns the cursor pos from when we last got client info
    x = m_info.m_mx;
    y = m_info.m_my;
}

void
ClientProxy1_0::enter(SInt32 xAbs, SInt32 yAbs,
                UInt32 seqNum, KeyModifierMask mask, bool)
{
    LOG((CLOG_DEBUG1 "send enter to \"%s\", %d,%d %d %04x", getName().c_str(), xAbs, yAbs, seqNum, mask));
    ProtocolUtil::writef(getStream(), kMsgCEnter,
                                xAbs, yAbs, seqNum, mask);
}

bool
ClientProxy1_0::leave()
{
    LOG((CLOG_DEBUG1 "send leave to \"%s\"", getName().c_str()));
    ProtocolUtil::writef(getStream(), kMsgCLeave);

    // we can never prevent the user from leaving
    return true;
}

void
ClientProxy1_0::setClipboard(ClipboardID id, const IClipboard* clipboard)
{
    // ignore -- deprecated in protocol 1.0
}

void
ClientProxy1_0::grabClipboard(ClipboardID id)
{
    LOG((CLOG_DEBUG "send grab clipboard %d to \"%s\"", id, getName().c_str()));
    ProtocolUtil::writef(getStream(), kMsgCClipboard, id, 0);

    // this clipboard is now dirty
    m_clipboard[id].m_dirty = true;
}

void
ClientProxy1_0::setClipboardDirty(ClipboardID id, bool dirty)
{
    m_clipboard[id].m_dirty = dirty;
}

void
ClientProxy1_0::keyDown(KeyID key, KeyModifierMask mask, KeyButton)
{
    LOG((CLOG_DEBUG1 "send key down to \"%s\" id=%d, mask=0x%04x", getName().c_str(), key, mask));
    ProtocolUtil::writef(getStream(), kMsgDKeyDown1_0, key, mask);
}

void
ClientProxy1_0::keyRepeat(KeyID key, KeyModifierMask mask,
                SInt32 count, KeyButton)
{
    LOG((CLOG_DEBUG1 "send key repeat to \"%s\" id=%d, mask=0x%04x, count=%d", getName().c_str(), key, mask, count));
    ProtocolUtil::writef(getStream(), kMsgDKeyRepeat1_0, key, mask, count);
}

void
ClientProxy1_0::keyUp(KeyID key, KeyModifierMask mask, KeyButton)
{
    LOG((CLOG_DEBUG1 "send key up to \"%s\" id=%d, mask=0x%04x", getName().c_str(), key, mask));
    ProtocolUtil::writef(getStream(), kMsgDKeyUp1_0, key, mask);
}

void
ClientProxy1_0::mouseDown(ButtonID button)
{
    LOG((CLOG_DEBUG1 "send mouse down to \"%s\" id=%d", getName().c_str(), button));
    ProtocolUtil::writef(getStream(), kMsgDMouseDown, button);
}

void
ClientProxy1_0::mouseUp(ButtonID button)
{
    LOG((CLOG_DEBUG1 "send mouse up to \"%s\" id=%d", getName().c_str(), button));
    ProtocolUtil::writef(getStream(), kMsgDMouseUp, button);
}

void
ClientProxy1_0::mouseMove(SInt32 xAbs, SInt32 yAbs)
{
    LOG((CLOG_DEBUG2 "send mouse move to \"%s\" %d,%d", getName().c_str(), xAbs, yAbs));
    ProtocolUtil::writef(getStream(), kMsgDMouseMove, xAbs, yAbs);
}

void
ClientProxy1_0::mouseRelativeMove(SInt32, SInt32)
{
    // ignore -- not supported in protocol 1.0
}

void
ClientProxy1_0::mouseWheel(SInt32, SInt32 yDelta)
{
    // clients prior to 1.3 only support the y axis
    LOG((CLOG_DEBUG2 "send mouse wheel to \"%s\" %+d", getName().c_str(), yDelta));
    ProtocolUtil::writef(getStream(), kMsgDMouseWheel1_0, yDelta);
}

void
ClientProxy1_0::sendDragInfo(UInt32 fileCount, const char* info, size_t size)
{
    // ignore -- not supported in protocol 1.0
    LOG((CLOG_DEBUG "draggingInfoSending not supported"));
}

void
ClientProxy1_0::fileChunkSending(UInt8 mark, char* data, size_t dataSize)
{
    // ignore -- not supported in protocol 1.0
    LOG((CLOG_DEBUG "fileChunkSending not supported"));
}

void
ClientProxy1_0::screensaver(bool on)
{
    LOG((CLOG_DEBUG1 "send screen saver to \"%s\" on=%d", getName().c_str(), on ? 1 : 0));
    ProtocolUtil::writef(getStream(), kMsgCScreenSaver, on ? 1 : 0);
}

void
ClientProxy1_0::resetOptions()
{
    LOG((CLOG_DEBUG1 "send reset options to \"%s\"", getName().c_str()));
    ProtocolUtil::writef(getStream(), kMsgCResetOptions);

    // reset heart rate and death
    resetHeartbeatRate();
    removeHeartbeatTimer();
    addHeartbeatTimer();
}

void
ClientProxy1_0::setOptions(const OptionsList& options)
{
    LOG((CLOG_DEBUG1 "send set options to \"%s\" size=%d", getName().c_str(), options.size()));
    ProtocolUtil::writef(getStream(), kMsgDSetOptions, &options);

    // check options
    for (UInt32 i = 0, n = (UInt32)options.size(); i < n; i += 2) {
        if (options[i] == kOptionHeartbeat) {
            double rate = 1.0e-3 * static_cast<double>(options[i + 1]);
            if (rate <= 0.0) {
                rate = -1.0;
            }
            setHeartbeatRate(rate, rate * kHeartBeatsUntilDeath);
            removeHeartbeatTimer();
            addHeartbeatTimer();
        }
    }
}

bool
ClientProxy1_0::recvInfo()
{
    // parse the message
    SInt16 x, y, w, h, dummy1, mx, my;
    if (!ProtocolUtil::readf(getStream(), kMsgDInfo + 4,
                            &x, &y, &w, &h, &dummy1, &mx, &my)) {
        return false;
    }
    LOG((CLOG_DEBUG "received client \"%s\" info shape=%d,%d %dx%d at %d,%d", getName().c_str(), x, y, w, h, mx, my));

    // validate
    if (w <= 0 || h <= 0) {
        return false;
    }
    if (mx < x || mx >= x + w || my < y || my >= y + h) {
        mx = x + w / 2;
        my = y + h / 2;
    }

    // save
    m_info.m_x  = x;
    m_info.m_y  = y;
    m_info.m_w  = w;
    m_info.m_h  = h;
    m_info.m_mx = mx;
    m_info.m_my = my;

    // acknowledge receipt
    LOG((CLOG_DEBUG1 "send info ack to \"%s\"", getName().c_str()));
    ProtocolUtil::writef(getStream(), kMsgCInfoAck);
    return true;
}

bool
ClientProxy1_0::recvClipboard()
{
    // deprecated in protocol 1.0
    return false;
}

bool
ClientProxy1_0::recvGrabClipboard()
{
    // parse message
    ClipboardID id;
    UInt32 seqNum;
    if (!ProtocolUtil::readf(getStream(), kMsgCClipboard + 4, &id, &seqNum)) {
        return false;
    }
    LOG((CLOG_DEBUG "received client \"%s\" grabbed clipboard %d seqnum=%d", getName().c_str(), id, seqNum));

    // validate
    if (id >= kClipboardEnd) {
        return false;
    }

    // notify
    ClipboardInfo* info   = new ClipboardInfo;
    info->m_id             = id;
    info->m_sequenceNumber = seqNum;
    m_events->addEvent(Event(m_events->forClipboard().clipboardGrabbed(),
                            getEventTarget(), info));

    return true;
}

//
// ClientProxy1_0::ClientClipboard
//

ClientProxy1_0::ClientClipboard::ClientClipboard() :
    m_clipboard(),
    m_sequenceNumber(0),
    m_dirty(true)
{
    // do nothing
}
