/*
 * Deskflow -- mouse and keyboard sharing utility
 * Copyright (C) 2012-2016 Symless Ltd.
 * Copyright (C) 2012 Nick Bolton
 *
 * 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 "ipc/IpcLogOutputter.h"

#include "arch/Arch.h"
#include "arch/XArch.h"
#include "base/Event.h"
#include "base/EventQueue.h"
#include "base/TMethodEventJob.h"
#include "base/TMethodJob.h"
#include "common/ipc.h"
#include "ipc/IpcClientProxy.h"
#include "ipc/IpcMessage.h"
#include "ipc/IpcServer.h"
#include "mt/Thread.h"

enum EIpcLogOutputter
{
  kBufferMaxSize = 1000,
  kMaxSendLines = 100,
  kBufferRateWriteLimit = 1000, // writes per kBufferRateTime
  kBufferRateTimeLimit = 1      // seconds
};

IpcLogOutputter::IpcLogOutputter(IpcServer &ipcServer, IpcClientType clientType, bool useThread)
    : m_ipcServer(ipcServer),
      m_bufferMutex(ARCH->newMutex()),
      m_sending(false),
      m_bufferThread(nullptr),
      m_running(false),
      m_notifyCond(ARCH->newCondVar()),
      m_notifyMutex(ARCH->newMutex()),
      m_bufferThreadId(0),
      m_bufferWaiting(false),
      m_bufferMaxSize(kBufferMaxSize),
      m_bufferRateWriteLimit(kBufferRateWriteLimit),
      m_bufferRateTimeLimit(kBufferRateTimeLimit),
      m_bufferWriteCount(0),
      m_bufferRateStart(ARCH->time()),
      m_clientType(clientType),
      m_runningMutex(ARCH->newMutex())
{
  if (useThread) {
    m_bufferThread = new Thread(new TMethodJob<IpcLogOutputter>(this, &IpcLogOutputter::bufferThread));
  }
}

IpcLogOutputter::~IpcLogOutputter()
{
  close();

  ARCH->closeMutex(m_bufferMutex);

  if (m_bufferThread != nullptr) {
    m_bufferThread->cancel();
    m_bufferThread->wait();
    delete m_bufferThread;
  }

  ARCH->closeCondVar(m_notifyCond);
  ARCH->closeMutex(m_notifyMutex);
}

void IpcLogOutputter::open(const char *title)
{
}

void IpcLogOutputter::close()
{
  if (m_bufferThread != nullptr) {
    ArchMutexLock lock(m_runningMutex);
    m_running = false;
    notifyBuffer();
    m_bufferThread->wait(5);
  }
}

void IpcLogOutputter::show(bool showIfEmpty)
{
}

bool IpcLogOutputter::write(ELevel, const char *text)
{
  // ignore events from the buffer thread (would cause recursion).
  if (m_bufferThread != nullptr && Thread::getCurrentThread().getID() == m_bufferThreadId) {
    return true;
  }

  appendBuffer(text);
  notifyBuffer();

  return true;
}

void IpcLogOutputter::appendBuffer(const String &text)
{
  ArchMutexLock lock(m_bufferMutex);

  double elapsed = ARCH->time() - m_bufferRateStart;
  if (elapsed < m_bufferRateTimeLimit) {
    if (m_bufferWriteCount >= m_bufferRateWriteLimit) {
      // discard the log line if we've logged too much.
      return;
    }
  } else {
    m_bufferWriteCount = 0;
    m_bufferRateStart = ARCH->time();
  }

  if (m_buffer.size() >= m_bufferMaxSize) {
    // if the queue is exceeds size limit,
    // throw away the oldest item
    m_buffer.pop_front();
  }

  m_buffer.push_back(text);
  m_bufferWriteCount++;
}

bool IpcLogOutputter::isRunning()
{
  ArchMutexLock lock(m_runningMutex);
  return m_running;
}

void IpcLogOutputter::bufferThread(void *)
{
  m_bufferThreadId = m_bufferThread->getID();
  m_running = true;

  try {
    while (isRunning()) {
      if (m_buffer.empty() || !m_ipcServer.hasClients(m_clientType)) {
        ArchMutexLock lock(m_notifyMutex);
        ARCH->waitCondVar(m_notifyCond, m_notifyMutex, -1);
      }

      sendBuffer();
    }
  } catch (XArch &e) {
    LOG((CLOG_ERR "ipc log buffer thread error, %s", e.what()));
  }

  LOG((CLOG_DEBUG "ipc log buffer thread finished"));
}

void IpcLogOutputter::notifyBuffer()
{
  ArchMutexLock lock(m_notifyMutex);
  ARCH->broadcastCondVar(m_notifyCond);
}

String IpcLogOutputter::getChunk(size_t count)
{
  ArchMutexLock lock(m_bufferMutex);

  if (m_buffer.size() < count) {
    count = m_buffer.size();
  }

  String chunk;
  for (size_t i = 0; i < count; i++) {
    chunk.append(m_buffer.front());
    chunk.append("\n");
    m_buffer.pop_front();
  }
  return chunk;
}

void IpcLogOutputter::sendBuffer()
{
  if (m_buffer.empty() || !m_ipcServer.hasClients(m_clientType)) {
    return;
  }

  IpcLogLineMessage message(getChunk(kMaxSendLines));
  m_sending = true;
  m_ipcServer.send(message, IpcClientType::GUI);
  m_sending = false;
}

void IpcLogOutputter::bufferMaxSize(UInt16 bufferMaxSize)
{
  m_bufferMaxSize = bufferMaxSize;
}

UInt16 IpcLogOutputter::bufferMaxSize() const
{
  return m_bufferMaxSize;
}

void IpcLogOutputter::bufferRateLimit(UInt16 writeLimit, double timeLimit)
{
  m_bufferRateWriteLimit = writeLimit;
  m_bufferRateTimeLimit = timeLimit;
}
