/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache 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.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#define __STDC_CONSTANT_MACROS

#include <log4cxx/logstring.h>

#include <log4cxx/helpers/filewatchdog.h>

#include <log4cxx/helpers/loglog.h>

#include <log4cxx/helpers/transcoder.h>

#include <log4cxx/helpers/exception.h>

#include <log4cxx/helpers/threadutility.h>

#include <log4cxx/helpers/stringhelper.h>

#include <functional>

#include <chrono>

#include <thread>

#include <condition_variable>

using namespace LOG4CXX_NS;

using namespace LOG4CXX_NS::helpers;

long FileWatchdog::DEFAULT_DELAY = 60000;

struct FileWatchdog::FileWatchdogPrivate{

  FileWatchdogPrivate(const File& file1) :

    file(file1), delay(DEFAULT_DELAY), lastModif(0),

    warnedAlready(false),

    taskName{ LOG4CXX_STR("WatchDog_") + file1.getName() }

  { }

  /**

  The name of the file to observe  for changes.

  */

  File file;

  /**

  The delay to observe between every check.

  By default set DEFAULT_DELAY.*/

  long delay;

  log4cxx_time_t lastModif;

  bool warnedAlready;

  LogString taskName;

  ThreadUtility::ManagerWeakPtr taskManager;

};

FileWatchdog::FileWatchdog(const File& file1)

  : m_priv(std::make_unique<FileWatchdogPrivate>(file1))

{

}

FileWatchdog::~FileWatchdog()

{

  stop();

}

bool FileWatchdog::is_active()

{

  bool result = false;

  if (auto p = m_priv->taskManager.lock())

    result = p->value().hasPeriodicTask(m_priv->taskName);

  return result;

}

void FileWatchdog::stop()

{

  if (auto p = m_priv->taskManager.lock())

    p->value().removePeriodicTask(m_priv->taskName);

}

/**

Stop all tasks that periodically checks for a file change.

*/

void FileWatchdog::stopAll()

{

  ThreadUtility::instance()->removePeriodicTasksMatching(LOG4CXX_STR("WatchDog_"));

}

const File& FileWatchdog::file()

{

  return m_priv->file;

}

void FileWatchdog::checkAndConfigure()

{

  if (LogLog::isDebugEnabled())

  {

    LogString msg(LOG4CXX_STR("Checking ["));

    msg += m_priv->file.getPath();

    msg += LOG4CXX_STR("]");

    LogLog::debug(msg);

  }

  Pool pool1;

  if (!m_priv->file.exists(pool1))

  {

    if (!m_priv->warnedAlready)

    {

      LogLog::warn(LOG4CXX_STR("[")

        + m_priv->file.getPath()

        + LOG4CXX_STR("] does not exist."));

      m_priv->warnedAlready = true;

    }

  }

  else

  {

    auto thisMod = m_priv->file.lastModified(pool1);

    if (thisMod > m_priv->lastModif)

    {

      m_priv->lastModif = thisMod;

      doOnChange();

      m_priv->warnedAlready = false;

    }

  }

}

void FileWatchdog::start()

{

  auto taskManager = ThreadUtility::instancePtr();

  checkAndConfigure();

  if (!taskManager->value().hasPeriodicTask(m_priv->taskName))

  {

    if (LogLog::isDebugEnabled())

    {

      Pool p;

      LogString msg(LOG4CXX_STR("Checking ["));

      msg += m_priv->file.getPath();

      msg += LOG4CXX_STR("] at ");

      StringHelper::toString((int)m_priv->delay, p, msg);

      msg += LOG4CXX_STR(" ms interval");

      LogLog::debug(msg);

    }

    taskManager->value().addPeriodicTask(m_priv->taskName

      , std::bind(&FileWatchdog::checkAndConfigure, this)

      , std::chrono::milliseconds(m_priv->delay)

      );

    m_priv->taskManager = taskManager;

  }

}

void FileWatchdog::setDelay(long delay1){

  m_priv->delay = delay1;

  auto p = m_priv->taskManager.lock();

  if (p && p->value().hasPeriodicTask(m_priv->taskName))

  {

    p->value().removePeriodicTask(m_priv->taskName);

    p->value().addPeriodicTask(m_priv->taskName

      , std::bind(&FileWatchdog::checkAndConfigure, this)

      , std::chrono::milliseconds(m_priv->delay)

      );

  }

}

void FileWatchdog::setFile(const File& filename)

{

    m_priv->file = filename;

  m_priv->lastModif = 0;

}