/*
    This file is part of KMail, the KDE mail client.
    Copyright (c) 2000 Don Sanders <sanders@kde.org>

    KMail is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License, version 2, as
    published by the Free Software Foundation.

    KMail 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, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/


#include "kmstartup.h"

#include "kmkernel.h" //control center
#include "kcursorsaver.h"

#include <klocale.h>
#include <kcomponentdata.h>
#include <kconfig.h>
#include <kstandarddirs.h>
#include <kmessagebox.h>
#include <kcrash.h>
#include <kglobal.h>
#include <kaboutdata.h>
#include <kiconloader.h>
#include <kconfiggroup.h>
#include <kde_file.h>

#include <QHostInfo>

#include <errno.h>
#include <sys/types.h>
#include <sys/param.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <qfile.h>

#undef Status // stupid X headers

extern "C" {

// Crash recovery signal handler
void kmsignalHandler(int sigId)
{
  kmsetSignalHandler(SIG_DFL);
  fprintf(stderr, "*** KMail got signal %d (Exiting)\n", sigId);
  // try to cleanup all windows
  if (kmkernel) kmkernel->dumpDeadLetters();
  ::exit(-1); //
}

// Crash recovery signal handler
void kmcrashHandler(int sigId)
{
  kmsetSignalHandler(SIG_DFL);
  fprintf(stderr, "*** KMail got signal %d (Crashing)\n", sigId);
  // try to cleanup all windows
  if (kmkernel) kmkernel->dumpDeadLetters();
  // Return to DrKonqi.
}
//-----------------------------------------------------------------------------


void kmsetSignalHandler(void (*handler)(int))
{
  KDE_signal(SIGTERM, handler);
  KDE_signal(SIGHUP,  handler);
  KCrash::setEmergencySaveFunction(kmcrashHandler);
}

}
//-----------------------------------------------------------------------------

namespace KMail {

void checkConfigUpdates() {
  static const char * const updates[] = {
    "9",
    "3.1-update-identities",
    "3.1-use-identity-uoids",
    "3.1-new-mail-notification",
    "3.2-update-loop-on-goto-unread-settings",
    "3.1.4-dont-use-UOID-0-for-any-identity",  //krazy:exclude=spelling
    "3.2-misc",
    "3.2-moves",
    "3.3-use-ID-for-accounts",
    "3.3-update-filter-rules",
    "3.3-move-identities-to-own-file",
    "3.3-aegypten-kpgprc-to-kmailrc",
    "3.3-aegypten-kpgprc-to-libkleopatrarc",
    "3.3-aegypten-emailidentities-split-sign-encr-keys",
    "3.3-misc",
    "3.3b1-misc",
    "3.4-misc",
    "3.4a",
    "3.4b",
    "3.4.1",
    "3.5.4",
    "3.5.7-imap-flag-migration",
    "4.0-misc",
    "4.2"
  };
  static const int numUpdates = sizeof updates / sizeof *updates;
  // Warning: do not remove entries in the above array, or the update-level check below will break

  KSharedConfig::Ptr config = KMKernel::config();
  KConfigGroup startup( config, "Startup" );
  const int configUpdateLevel = startup.readEntry( "update-level", 0 );
  if ( configUpdateLevel == numUpdates ) // Optimize for the common case that everything is OK
    return;

  for ( int i = configUpdateLevel ; i < numUpdates ; ++i ) {
    config->checkUpdate( updates[i], "kmail.upd" );
  }
  startup.writeEntry( "update-level", numUpdates );
}

void lockOrDie() {
// Check and create a lock file to prevent concurrent access to kmail files
  QString appName = KGlobal::mainComponent().componentName();
  if ( appName.isEmpty() )
    appName = "kmail";

  QString programName;
  const KAboutData *about = KGlobal::mainComponent().aboutData();
  if ( about )
    programName = about->programName();
  if ( programName.isEmpty() )
    programName = i18n("KMail");

  QString lockLocation = KStandardDirs::locateLocal("data", "kmail/lock");
  KConfig config(lockLocation, KConfig::SimpleConfig);
  KConfigGroup group(&config, "");
  int oldPid = group.readEntry("pid", -1 );
  kDebug() << "oldPid=" << oldPid;
  const QString oldHostName = group.readEntry("hostname");
  const QString oldAppName = group.readEntry( "appName", appName );
  const QString oldProgramName = group.readEntry( "programName", programName );
  const QString hostName = QHostInfo::localHostName();
  bool first_instance = false;
  if ( oldPid == -1 ) {
    first_instance = true;
  } else if ( hostName == oldHostName && oldPid != getpid() ) {
    // check if the lock file is stale
#ifdef Q_OS_LINUX //krazy:exclude=cpp
    if ( ::access("/proc", X_OK ) == 0 ) {
      // On linux with /proc we can even check that
      // it's really kmail and not something else
      char path_buffer[MAXPATHLEN + 1];
      path_buffer[MAXPATHLEN] = 0;
      const QString procPath = QString( "/proc/%1/exe" ).arg( oldPid );
      const int length =
        readlink( procPath.toLatin1(), path_buffer, MAXPATHLEN );
      if ( length == -1 ) { // no such pid
        first_instance = true;
      } else {
        path_buffer[length] = '\0';
        const QString path = QFile::decodeName( path_buffer );
        kDebug() << path;
        const int pos = path.lastIndexOf( '/' );
        const QString fileName = path.mid( pos + 1 );
        kDebug() << "Found process" << oldPid
                     << "running. It's:" << fileName;
        first_instance = fileName != "kmail" && fileName != "kontact";
      }
    } else
#endif
    {
      // Otherwise we just check if the other pid is currently running.
      // Not 100% correct but better safe than sorry.
      if ( kill(oldPid, 0) == -1 )
        first_instance = ( errno == ESRCH );
    }
  }

  if ( !first_instance ) {
    QString msg;
    if ( oldHostName == hostName ) {
      // this can only happen if the user is running this application on
      // different displays on the same machine. All other cases will be
      // taken care of by KUniqueApplication()
      if ( oldAppName == appName )
        msg = i18n("%1 already seems to be running on another display on "
                   "this machine. Running %2 more than once "
                   "can cause the loss of mail. You should not start %1 "
                   "unless you are sure that it is not already running.",
                   programName, programName );
              // QString::arg( st ) only replaces the first occurrence of %1
              // with st while QString::arg( s1, s2 ) replacess all occurrences
              // of %1 with s1 and all occurrences of %2 with s2. So don't
              // even think about changing the above to .arg( programName ).
      else
        msg = i18n("%1 seems to be running on another display on this "
                   "machine. Running %1 and %2 at the same "
                   "time can cause the loss of mail. You should not start %2 "
                   "unless you are sure that %1 is not running.",
                   oldProgramName, programName );
    }
    else {
      if ( oldAppName == appName )
        msg = i18n("%1 already seems to be running on %2. Running %1 more "
                   "than once can cause the loss of mail. You should not "
                   "start %1 on this computer unless you are sure that it is "
                   "not already running on %2.",
                   programName, oldHostName );
      else
        msg = i18n("%1 seems to be running on %3. Running %1 and %2 at the "
                   "same time can cause the loss of mail. You should not "
                   "start %2 on this computer unless you are sure that %1 is "
                   "not running on %3.",
                    oldProgramName, programName, oldHostName );
    }

    KCursorSaver idle( KBusyPtr::idle() );
    if ( KMessageBox::No ==
         KMessageBox::warningYesNo( 0, msg, QString(),
           KGuiItem(i18nc("Start kmail even when another instance is running.", "Start %1", programName )),
           KGuiItem(i18nc("Do not start another kmail instance.","Exit")) ) ) {
      exit(1);
    }
  }

  qlonglong pid = static_cast<qlonglong>( getpid() );
  group.writeEntry( "pid", pid );
  group.writeEntry( "hostname", hostName );
  group.writeEntry( "appName", appName );
  group.writeEntry( "programName", programName );
  group.sync();
}

void insertLibraryCataloguesAndIcons() {
  static const char * const catalogs[] = {
    "libkdepim",
    "libksieve",
    "libkleopatra",
    "libkpgp",
    "libkmime",
    "libmessagelist",
    "libmessagecore"
  };

  KLocale * l = KGlobal::locale();
  KIconLoader * il = KIconLoader::global();
  for ( unsigned int i = 0 ; i < sizeof catalogs / sizeof *catalogs ; ++i ) {
    l->insertCatalog( catalogs[i] );
    il->addAppDir( catalogs[i] );
  }

}

void cleanup()
{
  const QString lockLocation = KStandardDirs::locateLocal("data", "kmail/lock");
  KConfig config(lockLocation, KConfig::SimpleConfig);
  KConfigGroup group(&config, "");
  group.writeEntry("pid", -1);
  group.sync();
}
}
