/*
    kshorturifilter.h

    This file is part of the KDE project
    Copyright (C) 2000 Dawit Alemayehu <adawit@kde.org>
    Copyright (C) 2000 Malte Starostik <starosti@zedat.fu-berlin.de>

    This program 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 2 of the License, or
    (at your option) any later version.

    This program 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include <stdlib.h>
#include <unistd.h>
#include <pwd.h>
#include <sys/stat.h>

#include <qdir.h>
#include <qregexp.h>

#include <kapplication.h>
#include <kdebug.h>
#include <kprotocolinfo.h>
#include <kstandarddirs.h>
#include <kconfig.h>

#include "kshorturifilter.h"

#define FQDN_PATTERN    "(?:[a-zA-Z0-9][a-zA-Z0-9+-]*\\.[a-zA-Z]+)"
#define IPv4_PATTERN    "[0-9]{1,3}\\.[0-9]{1,3}(?:\\.[0-9]{0,3})?(?:\\.[0-9]{0,3})?"
#define IPv6_PATTERN    "^\\[.*\\]"
#define ENV_VAR_PATTERN "\\$[a-zA-Z_][a-zA-Z0-9_]*"

#define QFL1(x) QString::fromLatin1(x)
 
 /**
  * IMPORTANT: if you change anything here, please run the regression test
  * kdelibs/kio/tests/kurifiltertest
  */
  
typedef QMap<QString,QString> EntryMap;

static bool isValidShortURL( const QString& cmd, bool verbose = false )
{
  // Examples of valid short URLs:
  // "kde.org", "foo.bar:8080", "user@foo.bar:3128"
  // "192.168.1.0", "127.0.0.1:3128"
  // "[FEDC:BA98:7654:3210:FEDC:BA98:7654:3210]"
  QRegExp exp;
  
  // Match FQDN_PATTERN
  exp.setPattern( QFL1(FQDN_PATTERN) );
  if ( cmd.contains( exp ) )
  {
    if (verbose)
      kdDebug() << "KShortURIFilter::isValidShortURL: " << cmd 
                << " matches FQDN_PATTERN" << endl;
    return true;  
  }
  
  // Match IPv4 addresses
  exp.setPattern( QFL1(IPv4_PATTERN) );
  if ( cmd.contains( exp ) )
  {
    if (verbose)
      kdDebug() << "KShortURIFilter::isValidShortURL: " << cmd 
                << " matches IPv4_PATTERN" << endl;  
    return true;
  }
    
  // Match IPv6 addresses
  exp.setPattern( QFL1(IPv6_PATTERN) );
  if ( cmd.contains( exp ) )
  {
    if (verbose)
      kdDebug() << "KShortURIFilter::isValidShortURL: " << cmd 
                << " matches IPv6_PATTERN" << endl;
    return true;
  }
  
  if (verbose)
    kdDebug() << "KShortURIFilter::isValidShortURL: '" << cmd 
              << "' is not a short URL." << endl;
  
  return false;
}

static QString removeArgs( const QString& _cmd )
{
  QString cmd( _cmd );

  if( cmd[0] != '\'' && cmd[0] != '"' )
  {
    // Remove command-line options (look for first non-escaped space)
    int spacePos = 0;

    do
    {
      spacePos = cmd.find( ' ', spacePos+1 );
    } while ( spacePos > 1 && cmd[spacePos - 1] == '\\' );

    if( spacePos > 0 )
    {
      cmd = cmd.left( spacePos );
      //kdDebug() << k_funcinfo << "spacePos=" << spacePos << " returning " << cmd << endl;
    }
  }
  
  return cmd;
}

KShortURIFilter::KShortURIFilter( QObject *parent, const char *name,
                                  const QStringList & /*args*/ )
                :KURIFilterPlugin( parent, name ? name : "kshorturifilter", 1.0),
                 DCOPObject("KShortURIFilterIface")
{
    configure();
}

bool KShortURIFilter::filterURI( KURIFilterData& data ) const
{
 /*
  * Here is a description of how the shortURI deals with the supplied
  * data.  First it expands any environment variable settings and then
  * deals with special shortURI cases. These special cases are the "smb:"
  * URL scheme which is very specific to KDE, "#" and "##" which are
  * shortcuts for man:/ and info:/ protocols respectively. It then handles
  * local files.  Then it checks to see if the URL is valid and one that is
  * supported by KDE's IO system.  If all the above checks fails, it simply
  * lookups the URL in the user-defined list and returns without filtering
  * if it is not found. TODO: the user-defined table is currently only manually
  * hackable and is missing a config dialog.
  */

  KURL url = data.uri();
  QString cmd = data.typedString();
  bool isMalformed = !url.isValid();
  //kdDebug() << "url=" << url.url() << " cmd=" << cmd << " isMalformed=" << isMalformed << endl;

  if (!isMalformed &&
      (url.protocol().length() == 4) && 
      (url.protocol() != QString::fromLatin1("http")) &&
      (url.protocol()[0]=='h') &&
      (url.protocol()[1]==url.protocol()[2]) &&
      (url.protocol()[3]=='p'))
  {
     // Handle "encrypted" URLs like: h++p://www.kde.org
     url.setProtocol( QString::fromLatin1("http"));
     setFilteredURI( data, url);
     setURIType( data, KURIFilterData::NET_PROTOCOL );
     return true;
  }

  // TODO: Make this a bit more intelligent for Minicli! There
  // is no need to make comparisons if the supplied data is a local
  // executable and only the argument part, if any, changed! (Dawit)
  // You mean caching the last filtering, to try and reuse it, to save stat()s? (David)

  // Handle MAN & INFO pages shortcuts...
  QString man_proto = QFL1("man:");
  QString info_proto = QFL1("info:");
  if( cmd[0] == '#' ||
      cmd.find( man_proto, 0, true ) == 0 ||
      cmd.find( info_proto, 0, true ) == 0 )
  {
    if( cmd.left(2) == QFL1("##") )
      cmd = QFL1("info:/") + cmd.mid(2);
    else if ( cmd[0] == '#' )
      cmd = QFL1("man:/") + cmd.mid(1);

    else if ((cmd==info_proto) || (cmd==man_proto))
      cmd+='/';

    setFilteredURI( data, KURL( cmd ));
    setURIType( data, KURIFilterData::HELP );
    return true;
  }

  bool expanded = false;
  
  // Expanding shortcut to HOME URL...
  QString path;
  QString ref;
  QString query;
  
  if (KURL::isRelativeURL(cmd))
     path = cmd;
  else
  {
    if (url.isLocalFile())
     {
        path = url.path();
        ref = url.ref();
        query = url.query();
        if (path.isEmpty() && url.hasHost())
           path = "/";
     }
  }

  if( path[0] == '~' )
  {
    int slashPos = path.find('/');
    if( slashPos == -1 )
      slashPos = path.length();
    if( slashPos == 1 )   // ~/
    {
      path.replace ( 0, 1, QDir::homeDirPath() );
    }
    else // ~username/
    {
      QString user = path.mid( 1, slashPos-1 );
      struct passwd *dir = getpwnam(user.local8Bit().data());
      if( dir && strlen(dir->pw_dir) )
      {
        path.replace (0, slashPos, QString::fromLocal8Bit(dir->pw_dir));
      }
      else
      {
        QString msg = dir ? i18n("<qt><b>%1</b> does not have a home folder.</qt>").arg(user) :
                            i18n("<qt>There is no user called <b>%1</b>.</qt>").arg(user);
        setErrorMsg( data, msg );
        setURIType( data, KURIFilterData::ERROR );
        // Always return true for error conditions so
        // that other filters will not be invoked !!
        return true;
      }
    }
    expanded = true;
  }
  else if ( path[0] == '$' ) {
    // Environment variable expansion.
    QRegExp r (QFL1(ENV_VAR_PATTERN));
    if ( r.search( path ) == 0 )
    {
      const char* exp = getenv( path.mid( 1, r.matchedLength() - 1 ).local8Bit().data() );
      if(exp)
      {
        path.replace( 0, r.matchedLength(), QString::fromLocal8Bit(exp) );
        expanded = true;
      }
    }
  }

  if ( expanded )
  {
    // Look for #ref again, after $ and ~ expansion (testcase: $QTDIR/doc/html/functions.html#s)
    // Can't use KURL here, setPath would escape it...
    int pos = path.find('#');
    if ( pos > -1 )
    {
      ref = path.mid( pos + 1 );
      path = path.left( pos );
      //kdDebug() << "Extracted ref: path=" << path << " ref=" << ref << endl;
    }
  }


  bool isLocalFullPath = (!path.isEmpty() && path[0] == '/');

  // Checking for local resource match...
  // Determine if "uri" is an absolute path to a local resource  OR
  // A local resource with a supplied absolute path in KURIFilterData
  QString abs_path = data.absolutePath();

  bool canBeAbsolute = (isMalformed && !abs_path.isEmpty());
  bool canBeLocalAbsolute = (canBeAbsolute && abs_path[0] =='/');
  bool exists = false;

  /*kdDebug() << "abs_path=" << abs_path << " malformed=" << isMalformed
            << " canBeLocalAbsolute=" << canBeLocalAbsolute << endl;*/

  struct stat buff;
  if ( canBeLocalAbsolute )
  {
    QString abs = QDir::cleanDirPath( abs_path );
    // combine absolute path (abs_path) and relative path (cmd) into abs_path
    int len = path.length();
    if( (len==1 && path[0]=='.') || (len==2 && path[0]=='.' && path[1]=='.') )
        path += '/';
    //kdDebug() << "adding " << abs << " and " << path << endl;
    abs = QDir::cleanDirPath(abs + '/' + path);
    //kdDebug() << "checking whether " << abs << " exists." << endl;
    // Check if it exists
    if( stat( QFile::encodeName(abs).data(), &buff ) == 0 )
    {
        path = abs; // yes -> store as the new cmd
        exists = true;
        isLocalFullPath = true;
    }
  }

  if( isLocalFullPath && !exists )
  {
    exists = ( stat( QFile::encodeName(path).data() , &buff ) == 0 );
    if ( !exists && !query.isEmpty() ) { // maybe what we thought was a 'query', is part of the path (#58990)
        QString pathWithQuery = path + KURL::decode_string(query, 106 /* utf-8 */);
        if ( stat( QFile::encodeName(pathWithQuery).data() , &buff ) == 0 ) {
            path = pathWithQuery;
            exists = true;
            query = QString::null;
        }
    }
  }

  //kdDebug() << "path =" << path << " isLocalFullPath=" << isLocalFullPath << " exists=" << exists << endl;
  if( exists )
  {
    KURL u;
    u.setPath(path);
    u.setRef(ref);
    u.setQuery(query);

    if (kapp && !kapp->authorizeURLAction( QString::fromLatin1("open"), KURL(), u))
    {
      // No authorisation, we pretend it's a file will get 
      // an access denied error later on.
      setFilteredURI( data, u );
      setURIType( data, KURIFilterData::LOCAL_FILE );
      return true;
    }

    // Can be abs path to file or directory, or to executable with args
    bool isDir = S_ISDIR( buff.st_mode );
    if( !isDir && access ( QFile::encodeName(path).data(), X_OK) == 0 )
    {
      //kdDebug() << "Abs path to EXECUTABLE" << endl;
      setFilteredURI( data, u );
      setURIType( data, KURIFilterData::EXECUTABLE );
      return true;
    }
    
    // Open "uri" as file:/xxx if it is a non-executable local resource.
    if( isDir || S_ISREG( buff.st_mode ) )
    {
      //kdDebug() << "Abs path as local file" << endl;
      setFilteredURI( data, u );
      setURIType( data, ( isDir ) ? KURIFilterData::LOCAL_DIR : KURIFilterData::LOCAL_FILE );
      return true;
    }
    
    // Should we return LOCAL_FILE for non-regular files too?
    kdDebug() << "File found, but not a regular file nor dir... socket?" << endl;
  }

  // Let us deal with possible relative URLs to see
  // if it is executable under the user's $PATH variable.
  // We try hard to avoid parsing any possible command
  // line arguments or options that might have been supplied.
  QString exe = removeArgs( cmd );
  //kdDebug() << k_funcinfo << "findExe with " << exe << endl;
  if( !KStandardDirs::findExe( exe ).isNull() && data.checkForExecutables() )
  {
    //kdDebug() << "EXECUTABLE  exe=" << exe << endl;
    setFilteredURI( data, KURL( exe ));
    // check if we have command line arguments
    if( exe != cmd )
        setArguments(data, cmd.right(cmd.length() - exe.length()));
    setURIType( data, KURIFilterData::EXECUTABLE );
    return true;
  }

  // Process URLs of known and supported protocols so we don't have
  // to resort to the pattern matching scheme below which can possibly
  // be slow things down...
  if ( !isMalformed && !isLocalFullPath )
  {
    QStringList protocols = KProtocolInfo::protocols();
    for( QStringList::ConstIterator it = protocols.begin(); it != protocols.end(); ++it )
    {
      if( (url.protocol() == *it) )
      {
        setFilteredURI( data, url );
        if ( *it == QFL1("man") || *it == QFL1("help") )
          setURIType( data, KURIFilterData::HELP );
        else
          setURIType( data, KURIFilterData::NET_PROTOCOL );
        return true;
      }
    }
  }

  // Okay this is the code that allows users to supply custom matches for
  // specific URLs using Qt's regexp class. This is hard-coded for now.
  // TODO: Make configurable at some point...
  if ( !cmd.contains( ' ' ) )
  {
    QValueList<URLHint>::ConstIterator it;
    for( it = m_urlHints.begin(); it != m_urlHints.end(); ++it )
    {
      QRegExp match( (*it).regexp );
      if ( match.search( cmd, 0 ) == 0 )
      {
        //kdDebug() << "match - prepending " << (*it).prepend << endl;
        cmd.prepend( (*it).prepend );
        setFilteredURI( data, KURL( cmd ) );
        setURIType( data, KURIFilterData::NET_PROTOCOL );
        return true;
      }
    }

    // If cmd is NOT a local resource, check if it is a valid "shortURL"
    // candidate and append the default protocol the user supplied. (DA)
    if ( isMalformed && isValidShortURL(cmd, m_bVerbose) )
    {
      if (m_bVerbose)
        kdDebug() << "Valid short url, from malformed url -> using default proto=" 
                  << m_strDefaultProtocol << endl;
      
      cmd.insert( 0, m_strDefaultProtocol );
      setFilteredURI( data, KURL( cmd ));
      setURIType( data, KURIFilterData::NET_PROTOCOL );
      return true;
    }
  }

  // If we previously determined that the URL might be a file,
  // and if it doesn't exist, then error
  if( isLocalFullPath && !exists )
  {
    KURL u;
    u.setPath(path);
    u.setRef(ref);

    if (kapp && !kapp->authorizeURLAction( QString::fromLatin1("open"), KURL(), u))
    {
      // No authorisation, we pretend it exists and will get 
      // an access denied error later on.
      setFilteredURI( data, u );
      setURIType( data, KURIFilterData::LOCAL_FILE );
      return true;
    }
    //kdDebug() << "fileNotFound -> ERROR" << endl;
    setErrorMsg( data, i18n( "<qt>The file or folder <b>%1</b> does not exist." ).arg( data.uri().prettyURL() ) );
    setURIType( data, KURIFilterData::ERROR );
    return true;
  }

  // If we reach this point, we cannot filter this thing so simply return false
  // so that other filters, if present, can take a crack at it.
  return false;
}

KCModule* KShortURIFilter::configModule( QWidget*, const char* ) const
{
    return 0; //new KShortURIOptions( parent, name );
}

QString KShortURIFilter::configName() const
{
    return i18n("&ShortURLs");
}

void KShortURIFilter::configure()
{
  KConfig config( name() + QFL1("rc"), false, false );
  m_strDefaultProtocol = config.readEntry( "DefaultProtocol", QFL1("http://") );
  m_bVerbose = config.readBoolEntry( "Verbose", false );
  QChar sep = config.readNumEntry( "PatternSeparator", ' ' );
  EntryMap patterns = config.entryMap( QFL1("Pattern") );
  const EntryMap protocols = config.entryMap( QFL1("Protocol") );
  
  for( EntryMap::Iterator it = patterns.begin(); it != patterns.end(); ++it )
  {
    QStringList regexps = QStringList::split (sep, it.data());
    for (QStringList::Iterator exp = regexps.begin(); exp != regexps.end(); ++exp)
    {
      QString protocol = protocols[it.key()];
      if (!protocol.isEmpty())
        m_urlHints.append( URLHint(*exp, protocol) );
    }
  }
}

K_EXPORT_COMPONENT_FACTORY( libkshorturifilter,
	                    KGenericFactory<KShortURIFilter>( "kcmkurifilt" ) )

#include "kshorturifilter.moc"
