/*=============================================================================

  Library: CTK

  Copyright (c) German Cancer Research Center,
    Division of Medical and Biological Informatics

  Licensed 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.

=============================================================================*/

#include "ctkPluginPrivate_p.h"

#include "ctkPluginConstants.h"
#include "ctkPluginDatabaseException.h"
#include "ctkPluginArchive_p.h"
#include "ctkPluginFrameworkContext_p.h"
#include "ctkPluginFrameworkUtil_p.h"
#include "ctkPluginActivator.h"
#include "ctkPluginContext_p.h"

#include "ctkServices_p.h"
#include "ctkServiceReferencePrivate.h"
#include "ctkServiceRegistration.h"

const ctkPlugin::States ctkPluginPrivate::RESOLVED_FLAGS = ctkPlugin::RESOLVED | ctkPlugin::STARTING | ctkPlugin::ACTIVE | ctkPlugin::STOPPING;

//----------------------------------------------------------------------------
ctkPluginPrivate::ctkPluginPrivate(
    QWeakPointer<ctkPlugin> qq,
    ctkPluginFrameworkContext* fw,
    ctkPluginArchive* pa)
      : q_ptr(qq), fwCtx(fw), id(pa->getPluginId()),
      location(pa->getPluginLocation().toString()), state(ctkPlugin::INSTALLED),
      archive(pa), pluginContext(0), pluginActivator(0), pluginLoader(pa->getLibLocation()),
      eagerActivation(false), activating(false), deactivating(false)
{
  //TODO
  //checkCertificates(pa);

  // Get library load hints
  if (fw->props.contains(ctkPluginConstants::FRAMEWORK_PLUGIN_LOAD_HINTS))
  {
    QVariant loadHintsVariant = fw->props[ctkPluginConstants::FRAMEWORK_PLUGIN_LOAD_HINTS];
    if (loadHintsVariant.isValid())
    {
      QLibrary::LoadHints loadHints = loadHintsVariant.value<QLibrary::LoadHints>();
      pluginLoader.setLoadHints(loadHints);
    }
  }

  checkManifestHeaders();

  pluginDir = fwCtx->getDataStorage(id);
//  int oldStartLevel = archive->getStartLevel();
  try
  {
    //TODO: StartLevel Service
    //if (fwCtx->startLevelController == 0)
    //{
      archive->setStartLevel(0);
    //}
//    else
//    {
//      if (oldStartLevel == -1)
//      {
//        archive->setStartLevel(fwCtx->startLevelController->getInitialPluginStartLevel());
//      }
//    }
  }
  catch (const std::exception& e)
  {
    qDebug() << "Failed to set start level on #" << id << ":" << e.what();
  }

  lastModified = archive->getLastModified();
  if (lastModified.isNull())
  {
    modified();
  }

  // fill require list
  QString requireString = archive->getAttribute(ctkPluginConstants::REQUIRE_PLUGIN);
  QList<QMap<QString, QStringList> > requireList = ctkPluginFrameworkUtil::parseEntries(ctkPluginConstants::REQUIRE_PLUGIN,
                                                                                        requireString, true, true, false);
  QListIterator<QMap<QString, QStringList> > i(requireList);
  while (i.hasNext())
  {
    const QMap<QString, QStringList>& e = i.next();
    const QStringList& res = e.value(ctkPluginConstants::RESOLUTION_DIRECTIVE);
    const QStringList& version = e.value(ctkPluginConstants::PLUGIN_VERSION_ATTRIBUTE);
    ctkRequirePlugin* rp = new ctkRequirePlugin(this, e.value("$key").front(),
                                                res.empty() ? QString() : res.front(),
                                                version.empty() ? QString() : version.front());
    require.push_back(rp);
  }
}

//----------------------------------------------------------------------------
ctkPluginPrivate::ctkPluginPrivate(QWeakPointer<ctkPlugin> qq,
                                   ctkPluginFrameworkContext* fw,
                                   long id, const QString& loc, const QString& sym, const ctkVersion& ver)
                                     : q_ptr(qq), fwCtx(fw), id(id), location(loc), symbolicName(sym), version(ver),
                                     state(ctkPlugin::INSTALLED), archive(0), pluginContext(0),
                                     pluginActivator(0), eagerActivation(false), activating(false),
                                     deactivating(false)
{
  modified();
}

//----------------------------------------------------------------------------
ctkPluginPrivate::~ctkPluginPrivate()
{
  qDeleteAll(require);
  delete archive;
}

//----------------------------------------------------------------------------
ctkPlugin::State ctkPluginPrivate::getUpdatedState()
{
  if (state & ctkPlugin::INSTALLED)
  {
    try
    {
      if (state == ctkPlugin::INSTALLED)
      {
        fwCtx->resolvePlugin(this);
        state = ctkPlugin::RESOLVED;
        fwCtx->listeners.emitPluginChanged(ctkPluginEvent(ctkPluginEvent::RESOLVED, this->q_func()));
      }

    }
    catch (const ctkPluginException& pe)
    {
      this->fwCtx->listeners.frameworkError(this->q_func(), pe);
      throw;
    }
  }

  return state;
}

//----------------------------------------------------------------------------
QFileInfo ctkPluginPrivate::getDataRoot()
{
  return pluginDir;
}

//----------------------------------------------------------------------------
void ctkPluginPrivate::setAutostartSetting(const ctkPlugin::StartOptions& setting) {
  try
  {
    if (archive)
    {
      archive->setAutostartSetting(setting);
    }
  }
  catch (const ctkPluginDatabaseException& e)
  {
    this->fwCtx->listeners.frameworkError(this->q_func(), e);
  }
}

//----------------------------------------------------------------------------
void ctkPluginPrivate::ignoreAutostartSetting()
{
  try
  {
    if (archive)
    {
      archive->setAutostartSetting(-1);
    }
  }
  catch (const ctkPluginDatabaseException& e)
  {
    this->fwCtx->listeners.frameworkError(this->q_func(), e);
  }
}

//----------------------------------------------------------------------------
void ctkPluginPrivate::modified()
{
  lastModified = QDateTime::currentDateTime();
  if (archive)
  {
    archive->setLastModified(lastModified);
  }
}

//----------------------------------------------------------------------------
void ctkPluginPrivate::checkManifestHeaders()
{
  symbolicName = archive->getAttribute(ctkPluginConstants::PLUGIN_SYMBOLICNAME);

  if (symbolicName.isEmpty())
  {
    throw std::invalid_argument(std::string("ctkPlugin has no symbolic name, location=") +
                                qPrintable(location));
  }

  QString mpv = archive->getAttribute(ctkPluginConstants::PLUGIN_VERSION);
  if (!mpv.isEmpty())
  {
    try
    {
      version = ctkVersion(mpv);
    }
    catch (const std::exception& e)
    {
      throw std::invalid_argument(std::string("ctkPlugin does not specify a valid ") +
                                  qPrintable(ctkPluginConstants::PLUGIN_VERSION) + " header. Got exception: " + e.what());
    }
  }

  QSharedPointer<ctkPlugin> snp = fwCtx->plugins->getPlugin(symbolicName, version);
  // TBD! Should we allow update to same version?
  if (!snp.isNull() && snp->d_func() != this)
  {
    throw std::invalid_argument(std::string("Plugin with same symbolic name and version is already installed (")
                                + symbolicName.toStdString() + ", " + version.toString().toStdString() + ")");
  }

  QString ap = archive->getAttribute(ctkPluginConstants::PLUGIN_ACTIVATIONPOLICY);
  if (ctkPluginConstants::ACTIVATION_EAGER == ap)
  {
    eagerActivation = true;
  }

}

//----------------------------------------------------------------------------
void ctkPluginPrivate::finalizeActivation()
{
  switch (getUpdatedState())
  {
  case ctkPlugin::INSTALLED:
    // we shouldn't be here, getUpdatedState should have thrown
    // an exception during resolving the plugin
    throw ctkPluginException("Internal error: expected exception on plugin resolve not thrown!");
  case ctkPlugin::STARTING:
    if (activating) return; // finalization already in progress.
    // Lazy activation; fall through to RESOLVED.
  case ctkPlugin::RESOLVED:
    //6:
    state = ctkPlugin::STARTING;
    activating = true;
    qDebug() << "activating #" << this->id;
    //7:
    if (!pluginContext)
    {
      pluginContext.reset(new ctkPluginContext(this));
    }
    try
    {
      // start dependencies
      startDependencies();
      //TODO maybe call this in its own thread
      start0();
    }
    catch (...)
    {
      //8:
      state = ctkPlugin::STOPPING;
      // NYI, call outside lock
      fwCtx->listeners.emitPluginChanged(ctkPluginEvent(ctkPluginEvent::STOPPING, this->q_func()));
      removePluginResources();
      pluginContext.reset();

      state = ctkPlugin::RESOLVED;
      // NYI, call outside lock
      fwCtx->listeners.emitPluginChanged(ctkPluginEvent(ctkPluginEvent::STOPPED, this->q_func()));
      activating = false;
      throw;
    }
    activating = false;
    break;
      case ctkPlugin::ACTIVE:
    break;
      case ctkPlugin::STOPPING:
    // This happens if start is called from inside the ctkPluginActivator::stop method.
    // Don't allow it.
    throw ctkPluginException("start called from ctkPluginActivator::stop",
                             ctkPluginException::ACTIVATOR_ERROR);
      case ctkPlugin::UNINSTALLED:
    throw std::logic_error("ctkPlugin is in UNINSTALLED state");
  }
}

//----------------------------------------------------------------------------
void ctkPluginPrivate::stop0(bool wasStarted)
{
  //5:
  state = ctkPlugin::STOPPING;
  deactivating = true;
  //6-13:
  ctkPluginActivator* activator = 0;
  const std::exception* savedException = 0;
  try
  {
    //6:
    fwCtx->listeners.emitPluginChanged(ctkPluginEvent(ctkPluginEvent::STOPPING, q_func()));

    //7:
    if (wasStarted && pluginActivator)
    {
      try
      {
        pluginActivator->stop(pluginContext.data());
      }
      catch (const std::exception& e)
      {
        savedException = new ctkPluginException("ctkPlugin::stop: PluginActivator stop failed",
                                                ctkPluginException::ACTIVATOR_ERROR, &e);
      }
      if (state == ctkPlugin::UNINSTALLED)
      {
        throw std::logic_error("Plugin is uninstalled");
      }
      activator = pluginActivator;
      pluginActivator = 0;
    }

    // Call hooks after we've called PluginActivator::stop(), but before we've cleared all resources
    // TODO service listener hooks
    //fwCtx->listeners.serviceListeners.hooksBundleStopped(this);

    if (pluginContext)
    {
      pluginContext->d_func()->invalidate();
      pluginContext.reset();
    }
    //8-10:
    removePluginResources();
  }
  catch (const std::exception* exc)
  {
    savedException = exc;
  }

  delete activator;

  if (state != ctkPlugin::UNINSTALLED)
  {
    state = ctkPlugin::RESOLVED;
    deactivating = false;
    //fwCtx.packages.notifyAll();
    fwCtx->listeners.emitPluginChanged(ctkPluginEvent(ctkPluginEvent::STOPPED, q_func()));
  }

  if (savedException)
  {
    throw savedException;
  }
}

//----------------------------------------------------------------------------
QStringList ctkPluginPrivate::findResourceEntries(const QString& path,
                                                  const QString& pattern, bool recurse) const
{
  QStringList result;
  QStringList resources = archive->findResourcesPath(path);
  foreach(QString fp, resources)
  {
    QString lastComponentOfPath = fp.section('/', -1);
    bool isDirectory = fp.endsWith("/");

    if (!isDirectory &&
        (pattern.isNull() || ctkPluginFrameworkUtil::filterMatch(pattern, lastComponentOfPath)))
    {
      result << (path + fp);
    }
    if (isDirectory && recurse)
    {
      QStringList subResources = findResourceEntries(fp, pattern, recurse);
      foreach (QString subResource, subResources)
      {
        result << (path + subResource);
      }
    }
  }
  return result;
}

//----------------------------------------------------------------------------
void ctkPluginPrivate::startDependencies()
{
  QListIterator<ctkRequirePlugin*> i(this->require);
  while (i.hasNext())
  {
    ctkRequirePlugin* pr = i.next();
    QList<ctkPlugin*> pl = fwCtx->plugins->getPlugins(pr->name, pr->pluginRange);
    if (pl.isEmpty())
    {
      if (pr->resolution == ctkPluginConstants::RESOLUTION_MANDATORY)
      {
        // We should never get here, since the plugin can only be
        // started if all its dependencies could be resolved.
        throw ctkPluginException(
            QString("Internal error: dependent plugin %1 inside version range %2 is not installed.").
            arg(pr->name).arg(pr->pluginRange.toString()));
      }
      else
      {
        continue;
      }
    }

    // We take the first plugin in the list (highest version number)
    // Immediately start the dependencies (no lazy activation) but do not
    // change the autostart setting of the plugin.
    pl.front()->start(ctkPlugin::START_TRANSIENT);
  }
}

//----------------------------------------------------------------------------
void ctkPluginPrivate::start0()
{
  fwCtx->listeners.emitPluginChanged(ctkPluginEvent(ctkPluginEvent::STARTING, this->q_func()));

  try {
    pluginLoader.load();
    if (!pluginLoader.isLoaded())
    {
      throw ctkPluginException(QString("Loading plugin %1 failed: %2").arg(pluginLoader.fileName()).arg(pluginLoader.errorString()),
                               ctkPluginException::ACTIVATOR_ERROR);
    }

    pluginActivator = qobject_cast<ctkPluginActivator*>(pluginLoader.instance());
    if (!pluginActivator)
    {
      throw ctkPluginException(QString("Creating ctkPluginActivator instance from %1 failed: %2").arg(pluginLoader.fileName()).arg(pluginLoader.errorString()),
                               ctkPluginException::ACTIVATOR_ERROR);
    }

    pluginActivator->start(pluginContext.data());

    if (ctkPlugin::UNINSTALLED == state)
    {
      throw ctkPluginException("ctkPlugin uninstalled during start()", ctkPluginException::STATECHANGE_ERROR);
    }
    state = ctkPlugin::ACTIVE;
  }
  catch (const std::exception& e)
  {
    throw ctkPluginException("ctkPlugin start failed", ctkPluginException::ACTIVATOR_ERROR, &e);
  }

  qDebug() << "activating #" << id << "completed.";

  //10:
  fwCtx->listeners.emitPluginChanged(ctkPluginEvent(ctkPluginEvent::STARTED, this->q_func()));
}

//----------------------------------------------------------------------------
void ctkPluginPrivate::removePluginResources()
{
  // automatic disconnect due to Qt signal slot
  //fwCtx->listeners.removeAllListeners(this);

  QList<ctkServiceRegistration> srs = fwCtx->services->getRegisteredByPlugin(this);
  QMutableListIterator<ctkServiceRegistration> i(srs);
  while (i.hasNext())
  {
    try
    {
      i.next().unregister();
    }
    catch (const std::logic_error& /*ignore*/)
    {
      // Someone has unregistered the service after stop completed.
      // This should not occur, but we don't want get stuck in
      // an illegal state so we catch it.
    }
  }

  QList<ctkServiceRegistration> s = fwCtx->services->getUsedByPlugin(q_func());
  QListIterator<ctkServiceRegistration> i2(s);
  while (i2.hasNext())
  {
    i2.next().getReference().d_func()->ungetService(q_func(), false);
  }

}