/*
 * This file Copyright (C) 2009-2015 Mnemosyne LLC
 *
 * It may be used under the GNU GPL versions 2 or 3
 * or any future license endorsed by Mnemosyne LLC.
 *
 * $Id$
 */

#include <QFileInfo>
#include <QPushButton>

#include <libtransmission/transmission.h>
#include <libtransmission/utils.h> /* mime64 */
#include <libtransmission/variant.h>

#include "AddData.h"
#include "FreeSpaceLabel.h"
#include "OptionsDialog.h"
#include "Prefs.h"
#include "Session.h"
#include "Torrent.h"
#include "Utils.h"

/***
****
***/

OptionsDialog::OptionsDialog (Session& session, const Prefs& prefs, const AddData& addme, QWidget * parent):
  QDialog (parent, Qt::Dialog),
  mySession (session),
  myAdd (addme),
  myHaveInfo (false),
  myVerifyButton (nullptr),
  myVerifyFile (nullptr),
  myVerifyHash (QCryptographicHash::Sha1),
  myEditTimer (this)
{
  ui.setupUi (this);

  QString title;
  if (myAdd.type == AddData::FILENAME)
    title = tr ("Open Torrent from File");
  else
    title = tr ("Open Torrent from URL or Magnet Link");
  setWindowTitle (title);

  myEditTimer.setInterval (2000);
  myEditTimer.setSingleShot (true);
  connect (&myEditTimer, SIGNAL (timeout ()), this, SLOT (onDestinationChanged ()));

  if (myAdd.type == AddData::FILENAME)
    {
      ui.sourceStack->setCurrentWidget (ui.sourceButton);
      ui.sourceButton->setMode (PathButton::FileMode);
      ui.sourceButton->setTitle (tr ("Open Torrent"));
      ui.sourceButton->setNameFilter (tr ("Torrent Files (*.torrent);;All Files (*.*)"));
      ui.sourceButton->setPath (myAdd.filename);
      connect (ui.sourceButton, SIGNAL (pathChanged (QString)), this, SLOT (onSourceChanged ()));
    }
  else
    {
      ui.sourceStack->setCurrentWidget (ui.sourceEdit);
      ui.sourceEdit->setText (myAdd.readableName ());
      ui.sourceEdit->selectAll ();
      connect (ui.sourceEdit, SIGNAL (editingFinished ()), this, SLOT (onSourceChanged ()));
    }

  ui.sourceStack->setFixedHeight (ui.sourceStack->currentWidget ()->sizeHint ().height ());
  ui.sourceLabel->setBuddy (ui.sourceStack->currentWidget ());

  const QFontMetrics fontMetrics (font ());
  const int width = fontMetrics.size (0, QString::fromUtf8 ("This is a pretty long torrent filename indeed.torrent")).width ();
  ui.sourceStack->setMinimumWidth (width);

  const QString downloadDir (Utils::removeTrailingDirSeparator (prefs.getString (Prefs::DOWNLOAD_DIR)));
  ui.freeSpaceLabel->setSession (mySession);
  ui.freeSpaceLabel->setPath (downloadDir);

  if (session.isLocal ())
    {
      ui.destinationStack->setCurrentWidget (ui.destinationButton);
      ui.destinationButton->setMode (PathButton::DirectoryMode);
      ui.destinationButton->setTitle (tr ("Select Destination"));
      ui.destinationButton->setPath (downloadDir);
      myLocalDestination = downloadDir;
      connect (ui.destinationButton, SIGNAL (pathChanged (QString)), this, SLOT (onDestinationChanged ()));
    }
  else
    {
      ui.destinationStack->setCurrentWidget (ui.destinationEdit);
      ui.destinationEdit->setText (downloadDir);
      ui.freeSpaceLabel->setPath (downloadDir);
      connect (ui.destinationEdit, SIGNAL (textEdited (QString)), &myEditTimer, SLOT (start ()));
      connect (ui.destinationEdit, SIGNAL (editingFinished ()), this, SLOT (onDestinationChanged ()));
    }

  ui.destinationStack->setFixedHeight (ui.destinationStack->currentWidget ()->sizeHint ().height ());
  ui.destinationLabel->setBuddy (ui.destinationStack->currentWidget ());

  ui.filesView->setEditable (false);
  if (!session.isLocal ())
    ui.filesView->hideColumn (2); // hide the % done, since we've no way of knowing

  ui.priorityCombo->addItem (tr ("High"),   TR_PRI_HIGH);
  ui.priorityCombo->addItem (tr ("Normal"), TR_PRI_NORMAL);
  ui.priorityCombo->addItem (tr ("Low"),    TR_PRI_LOW);
  ui.priorityCombo->setCurrentIndex (1); // Normal

  if (session.isLocal ())
    {
      myVerifyButton = new QPushButton (tr ("&Verify Local Data"), this);
      ui.dialogButtons->addButton (myVerifyButton, QDialogButtonBox::ActionRole);
      connect (myVerifyButton, SIGNAL (clicked (bool)), this, SLOT (onVerify ()));
    }

  ui.startCheck->setChecked (prefs.getBool (Prefs::START));
  ui.trashCheck->setChecked (prefs.getBool (Prefs::TRASH_ORIGINAL));

  connect (ui.dialogButtons, SIGNAL (rejected ()), this, SLOT (deleteLater ()));
  connect (ui.dialogButtons, SIGNAL (accepted ()), this, SLOT (onAccepted ()));

  connect (ui.filesView, SIGNAL (priorityChanged (QSet<int>, int)), this, SLOT (onPriorityChanged (QSet<int>, int)));
  connect (ui.filesView, SIGNAL (wantedChanged (QSet<int>, bool)), this, SLOT (onWantedChanged (QSet<int>, bool)));

  connect (&myVerifyTimer, SIGNAL (timeout ()), this, SLOT (onTimeout ()));

  reload ();
}

OptionsDialog::~OptionsDialog ()
{
  clearInfo ();
}

/***
****
***/

void
OptionsDialog::clearInfo ()
{
  if (myHaveInfo)
    tr_metainfoFree (&myInfo);

  myHaveInfo = false;
  myFiles.clear ();
}

void
OptionsDialog::reload ()
{
  clearInfo ();
  clearVerify ();

  tr_ctor * ctor = tr_ctorNew (0);

  switch (myAdd.type)
    {
      case AddData::MAGNET:
        tr_ctorSetMetainfoFromMagnetLink (ctor, myAdd.magnet.toUtf8 ().constData ());
        break;

      case AddData::FILENAME:
        tr_ctorSetMetainfoFromFile (ctor, myAdd.filename.toUtf8 ().constData ());
        break;

      case AddData::METAINFO:
        tr_ctorSetMetainfo (ctor, reinterpret_cast<const quint8*> (myAdd.metainfo.constData ()), myAdd.metainfo.size ());
        break;

      default:
        break;
    }

  const int err = tr_torrentParse (ctor, &myInfo);
  myHaveInfo = !err;
  tr_ctorFree (ctor);

  ui.filesView->clear ();
  myFiles.clear ();
  myPriorities.clear ();
  myWanted.clear ();

  const bool haveFilesToShow = myHaveInfo && myInfo.fileCount > 0;

  ui.filesView->setVisible (haveFilesToShow);
  if (myVerifyButton != nullptr)
    myVerifyButton->setVisible (haveFilesToShow);
  layout ()->setSizeConstraint (haveFilesToShow ? QLayout::SetDefaultConstraint : QLayout::SetFixedSize);

  if (myHaveInfo)
    {
      myPriorities.insert (0, myInfo.fileCount, TR_PRI_NORMAL);
      myWanted.insert (0, myInfo.fileCount, true);

      for (tr_file_index_t i = 0; i < myInfo.fileCount; ++i)
        {
          TorrentFile file;
          file.index = i;
          file.priority = myPriorities[i];
          file.wanted = myWanted[i];
          file.size = myInfo.files[i].length;
          file.have = 0;
          file.filename = QString::fromUtf8 (myInfo.files[i].name);
          myFiles.append (file);
        }
    }

  ui.filesView->update (myFiles);
}

void
OptionsDialog::onPriorityChanged (const QSet<int>& fileIndices, int priority)
{
  for (const int i: fileIndices)
    myPriorities[i] = priority;
}

void
OptionsDialog::onWantedChanged (const QSet<int>& fileIndices, bool isWanted)
{
  for (const int i: fileIndices)
    myWanted[i] = isWanted;
}

void
OptionsDialog::onAccepted ()
{
  // rpc spec section 3.4 "adding a torrent"

  tr_variant args;
  tr_variantInitDict (&args, 10);
  QString downloadDir;

  // "download-dir"
  if (ui.destinationStack->currentWidget () == ui.destinationButton)
    downloadDir = myLocalDestination.absolutePath ();
  else
    downloadDir = ui.destinationEdit->text ();

  tr_variantDictAddStr (&args, TR_KEY_download_dir, downloadDir.toUtf8 ().constData ());

  // paused
  tr_variantDictAddBool (&args, TR_KEY_paused, !ui.startCheck->isChecked ());

  // priority
  const int index = ui.priorityCombo->currentIndex ();
  const int priority = ui.priorityCombo->itemData (index).toInt ();
  tr_variantDictAddInt (&args, TR_KEY_bandwidthPriority, priority);

  // files-unwanted
  int count = myWanted.count (false);
  if (count > 0)
    {
      tr_variant * l = tr_variantDictAddList (&args, TR_KEY_files_unwanted, count);
      for (int i = 0, n = myWanted.size (); i < n; ++i)
        {
          if (myWanted.at (i) == false)
            tr_variantListAddInt (l, i);
        }
    }

  // priority-low
  count = myPriorities.count (TR_PRI_LOW);
  if (count > 0)
    {
      tr_variant * l = tr_variantDictAddList (&args, TR_KEY_priority_low, count);
      for (int i = 0, n = myPriorities.size (); i < n; ++i)
        {
          if (myPriorities.at (i) == TR_PRI_LOW)
            tr_variantListAddInt (l, i);
        }
    }

  // priority-high
  count = myPriorities.count (TR_PRI_HIGH);
  if (count > 0)
    {
      tr_variant * l = tr_variantDictAddList (&args, TR_KEY_priority_high, count);
      for (int i = 0, n = myPriorities.size (); i < n; ++i)
        {
          if (myPriorities.at (i) == TR_PRI_HIGH)
            tr_variantListAddInt (l, i);
        }
    }

  mySession.addTorrent (myAdd, &args, ui.trashCheck->isChecked ());

  deleteLater ();
}

void
OptionsDialog::onSourceChanged ()
{
  if (ui.sourceStack->currentWidget () == ui.sourceButton)
    myAdd.set (ui.sourceButton->path ());
  else
    myAdd.set (ui.sourceEdit->text ());

  reload ();
}

void
OptionsDialog::onDestinationChanged ()
{
  if (ui.destinationStack->currentWidget () == ui.destinationButton)
    {
      myLocalDestination = ui.destinationButton->path ();
      ui.freeSpaceLabel->setPath (myLocalDestination.absolutePath ());
    }
  else
    {
      ui.freeSpaceLabel->setPath (ui.destinationEdit->text ());
    }
}

/***
****
****  VERIFY
****
***/

void
OptionsDialog::clearVerify ()
{
  myVerifyHash.reset ();
  myVerifyFile.close ();
  myVerifyFilePos = 0;
  myVerifyFlags.clear ();
  myVerifyFileIndex = 0;
  myVerifyPieceIndex = 0;
  myVerifyPiecePos = 0;
  myVerifyTimer.stop ();

  for (TorrentFile& f: myFiles)
    f.have = 0;

  ui.filesView->update (myFiles);
}

void
OptionsDialog::onVerify ()
{
  clearVerify ();
  myVerifyFlags.insert (0, myInfo.pieceCount, false);
  myVerifyTimer.setSingleShot (false);
  myVerifyTimer.start (0);
}

namespace
{
  uint64_t getPieceSize (const tr_info * info, tr_piece_index_t pieceIndex)
  {
    if (pieceIndex != info->pieceCount - 1)
      return info->pieceSize;
    return info->totalSize % info->pieceSize;
  }
}

void
OptionsDialog::onTimeout ()
{
  if (myFiles.isEmpty ())
    {
      myVerifyTimer.stop ();
      return;
    }

  const tr_file * file = &myInfo.files[myVerifyFileIndex];

  if (!myVerifyFilePos && !myVerifyFile.isOpen ())
    {
      const QFileInfo fileInfo (myLocalDestination, QString::fromUtf8 (file->name));
      myVerifyFile.setFileName (fileInfo.absoluteFilePath ());
      myVerifyFile.open (QIODevice::ReadOnly);
    }

  int64_t leftInPiece = getPieceSize (&myInfo, myVerifyPieceIndex) - myVerifyPiecePos;
  int64_t leftInFile = file->length - myVerifyFilePos;
  int64_t bytesThisPass = qMin (leftInFile, leftInPiece);
  bytesThisPass = qMin (bytesThisPass, static_cast<int64_t> (sizeof (myVerifyBuf)));

  if (myVerifyFile.isOpen () && myVerifyFile.seek (myVerifyFilePos))
    {
      int64_t numRead = myVerifyFile.read (myVerifyBuf, bytesThisPass);
      if (numRead == bytesThisPass)
        myVerifyHash.addData (myVerifyBuf, numRead);
    }

  leftInPiece -= bytesThisPass;
  leftInFile -= bytesThisPass;
  myVerifyPiecePos += bytesThisPass;
  myVerifyFilePos += bytesThisPass;

  myVerifyBins[myVerifyFileIndex] += bytesThisPass;

  if (leftInPiece == 0)
    {
      const QByteArray result (myVerifyHash.result ());
      const bool matches = !memcmp (result.constData (),
                                    myInfo.pieces[myVerifyPieceIndex].hash,
                                    SHA_DIGEST_LENGTH);
      myVerifyFlags[myVerifyPieceIndex] = matches;
      myVerifyPiecePos = 0;
      ++myVerifyPieceIndex;
      myVerifyHash.reset ();

      FileList changedFiles;
      if (matches)
        {
          for (auto i = myVerifyBins.begin (), end = myVerifyBins.end (); i != end; ++i)
            {
              TorrentFile& f (myFiles[i.key ()]);
              f.have += i.value ();
              changedFiles.append (f);
            }
        }
      ui.filesView->update (changedFiles);
      myVerifyBins.clear ();
    }

  if (leftInFile == 0)
    {
      myVerifyFile.close ();
      ++myVerifyFileIndex;
      myVerifyFilePos = 0;
    }

  bool done = myVerifyPieceIndex >= myInfo.pieceCount;
  if (done)
    {
      uint64_t have = 0;
      for (const TorrentFile& f: myFiles)
        have += f.have;

      if (!have) // everything failed
        {
          // did the user accidentally specify the child directory instead of the parent?
          const QStringList tokens = QString::fromUtf8 (file->name).split (QLatin1Char ('/'));
          if (!tokens.empty () && myLocalDestination.dirName () == tokens.at (0))
            {
              // move up one directory and try again
              myLocalDestination.cdUp ();
              onVerify ();
              done = false;
            }
        }
    }

  if (done)
    myVerifyTimer.stop ();
}