/* This file is part of Clementine.
   Copyright 2012, David Sansome <me@davidsansome.com>

   Clementine is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Clementine 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 Clementine.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "macfslistener.h"

#include <CoreFoundation/CFArray.h>
#include <Foundation/NSArray.h>
#include <Foundation/NSString.h>

#include "core/logging.h"
#include "core/scoped_nsobject.h"

MacFSListener::MacFSListener(QObject* parent)
    : FileSystemWatcherInterface(parent),
      run_loop_(NULL),
      stream_(NULL) {
}

void MacFSListener::Init() {
  run_loop_ = CFRunLoopGetCurrent();
}

void MacFSListener::EventStreamCallback(
    ConstFSEventStreamRef stream,
    void* user_data,
    size_t num_events,
    void* event_paths,
    const FSEventStreamEventFlags event_flags[],
    const FSEventStreamEventId event_ids[]) {
  MacFSListener* me = reinterpret_cast<MacFSListener*>(user_data);
  char** paths = reinterpret_cast<char**>(event_paths);
  for (int i = 0; i < num_events; ++i) {
    QString path = QString::fromUtf8(paths[i]);
    qLog(Debug) << "Something changed at:" << path;
    while (path.endsWith('/')) {
      path.chop(1);
    }
    emit me->PathChanged(path);
  }
}

void MacFSListener::AddPath(const QString& path) {
  Q_ASSERT(run_loop_);
  paths_.insert(path);
  UpdateStream();
}

void MacFSListener::Clear() {
  paths_.clear();
  UpdateStream();
}

void MacFSListener::UpdateStream() {
  if (stream_) {
    FSEventStreamStop(stream_);
    FSEventStreamInvalidate(stream_);
    FSEventStreamRelease(stream_);
    stream_ = NULL;
  }

  if (paths_.empty()) {
    return;
  }

  scoped_nsobject<NSMutableArray> array([[NSMutableArray alloc] init]);

  foreach (const QString& path, paths_) {
    scoped_nsobject<NSString> string(
        [[NSString alloc] initWithUTF8String: path.toUtf8().constData()]);
    [array addObject: string.get()];
  }

  FSEventStreamContext context;
  memset(&context, 0, sizeof(context));
  context.info = this;
  CFAbsoluteTime latency = 1.0;

  stream_ = FSEventStreamCreate(
      NULL,
      &EventStreamCallback,
      &context,  // Copied
      reinterpret_cast<CFArrayRef>(array.get()),
      kFSEventStreamEventIdSinceNow,
      latency,
      kFSEventStreamCreateFlagNone);

  FSEventStreamScheduleWithRunLoop(stream_, run_loop_, kCFRunLoopDefaultMode);
  FSEventStreamStart(stream_);
}
