/***************************************************************************
    begin                : Sat Sept 9 2003
    edit		 : Wed Jan 14 2009
    copyright            : (C) 2003 by Jeroen Wijnhout, 2007-2009 by Thomas Braun
    email                : Jeroen.Wijnhout@kdemail.net
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#include "kilelyxserver.h"

#include <sys/stat.h>
#include <stdlib.h> //getenv
#ifndef _MSC_VER
#include <unistd.h> //read
#else
#include <io.h>
#endif
#include <fcntl.h>

#include "kileactions.h"
#include "kiledebug.h"

#include <QDir>
#include <QFile>
#include <QFileInfo>
#include <QSocketNotifier>
#include <QRegularExpression>

#include <KLocalizedString>

KileLyxServer::KileLyxServer(bool startMe) :
    m_running(false)
{
#ifndef _MSC_VER
    m_perms = S_IRUSR | S_IWUSR;
#else
    m_perms = 0;
#endif
    KILE_DEBUG_MAIN << "===KileLyxServer::KileLyxServer(bool" << startMe << ")=== ";

    m_tempDir = new QTemporaryDir();
    if(!m_tempDir->isValid()) {
        KILE_DEBUG_MAIN << "an error occurred while creating a tempfile" ;
        return;
    }

    m_links << ".lyxpipe.in" << ".lyx/lyxpipe.in";
    m_links << ".lyxpipe.out" << ".lyx/lyxpipe.out";

    for(int i = 0; i < m_links.count() ; ++i) {
        m_pipes.append( m_tempDir->path() + QDir::separator() + m_links[i] );
        m_links[i].prepend(QDir::homePath() + QDir::separator() );
        KILE_DEBUG_MAIN << "m_pipes[" << i << "]=" << m_pipes[i];
        KILE_DEBUG_MAIN << "m_links[" << i << "]=" << m_links[i];
    }

    if(startMe) {
        start();
    }
}

KileLyxServer::~KileLyxServer()
{
    stop();
    removePipes();

    delete m_tempDir;

    for(QList<QFile*>::iterator i = m_pipeIn.begin(); i != m_pipeIn.end(); ++i) {
        delete *i;
    }

    for(QList<QSocketNotifier*>::iterator i = m_notifier.begin(); i != m_notifier.end(); ++i) {
        delete *i;
    }
}

bool KileLyxServer::start()
{
    if (m_running) {
        stop();
    }

    KILE_DEBUG_MAIN << "Starting the LyX server...";

    if (openPipes()) {
        QSocketNotifier *notifier;
        for(QList<QFile*>::iterator it = m_pipeIn.begin(); it != m_pipeIn.end(); ++it) {
            if ((*it)->fileName().right(3) == ".in" ) {
                notifier = new QSocketNotifier((*it)->handle(), QSocketNotifier::Read, this);
                connect(notifier, SIGNAL(activated(int)), this, SLOT(receive(int)));
                m_notifier.append(notifier);
                KILE_DEBUG_MAIN << "Created notifier for " << (*it)->fileName();
            }
            else {
                KILE_DEBUG_MAIN << "No notifier created for " << (*it)->fileName();
            }
        }
        m_running=true;
    }

    return m_running;
}

bool KileLyxServer::openPipes()
{
    KILE_DEBUG_MAIN << "===bool KileLyxServer::openPipes()===";

#ifdef Q_OS_WIN
    qCritical() << "kile's lyx server can not work on windows since we don't have pipes";
    qCritical() << "And also lyx itself does not support it, see  https://wiki.lyx.org/LyX/LyXServer";
    return false;
#else
    bool opened = false;
    QFileInfo pipeInfo,linkInfo;
    QFile *file;
    struct stat buf;
    struct stat *stats = &buf;

    QDir lyxDir(QDir::homePath() + QDir::separator() + ".lyx");
    if(!lyxDir.exists()) {
        KILE_DEBUG_MAIN << "Directory " << lyxDir.absolutePath() << " does not exist";
        if(mkdir(QFile::encodeName( lyxDir.path() ), m_perms | S_IXUSR) == -1) {
            qCritical() << "Could not create directory";
        }
        else {
            KILE_DEBUG_MAIN << "Directory created successfully";
        }
    }

    for(int i = 0; i < m_pipes.count(); ++i) {
        pipeInfo.setFile(m_pipes[i]);
        linkInfo.setFile(m_links[i]);

        QFile::remove(linkInfo.absoluteFilePath());
        linkInfo.refresh();

        KILE_DEBUG_MAIN << "pipe=" << m_pipes[i] << Qt::endl;
        KILE_DEBUG_MAIN << "link=" << m_links[i] << Qt::endl;

        if(!pipeInfo.exists()) {
            //create the dir first
            if(!QFileInfo::exists(pipeInfo.absolutePath())) {
                if(mkdir(QFile::encodeName( pipeInfo.path() ), m_perms | S_IXUSR) == -1) {
                    qCritical() << "Could not create directory for pipe";
                    continue;
                }
                else {
                    KILE_DEBUG_MAIN << "Created directory " << pipeInfo.path();
                }
            }
            if (mkfifo(QFile::encodeName( pipeInfo.absoluteFilePath() ), m_perms) != 0) {
                qCritical() << "Could not create pipe: " << pipeInfo.absoluteFilePath();
                continue;
            }
            else {
                KILE_DEBUG_MAIN << "Created pipe: " << pipeInfo.absoluteFilePath();
            }
        }

        if(symlink(QFile::encodeName(pipeInfo.absoluteFilePath()),QFile::encodeName(linkInfo.absoluteFilePath())) != 0) {
            qCritical() << "Could not create symlink: " << linkInfo.absoluteFilePath() << " --> " << pipeInfo.absoluteFilePath();
            continue;
        }

        // the file object will be deleted at the shutdown of the server in KileLyxServer::stop()
        file  = new QFile(pipeInfo.absoluteFilePath());
        pipeInfo.refresh();

        if(pipeInfo.exists() && file->open(QIODevice::ReadWrite)) { // in that order we don't create the file if it does not exist
            KILE_DEBUG_MAIN << "Opened file: " << pipeInfo.absoluteFilePath();
            fstat(file->handle(),stats);
            if(!S_ISFIFO(stats->st_mode)) {
                qCritical() << "The file " << pipeInfo.absoluteFilePath() <<  "we just created is not a pipe!";
                file->close();
                delete file;
                continue;
            }
            else {
                m_pipeIn.append(file);
                m_file.insert(file->handle(), file);
                opened = true;
                KILE_DEBUG_MAIN << "everything is correct :)" << Qt::endl;
            }
        }
        else {
            qCritical() << "Could not open " << pipeInfo.absoluteFilePath();
        }
    }
    return opened;
#endif
}

void KileLyxServer::stop()
{
    KILE_DEBUG_MAIN << "Stopping the LyX server...";

    for(QList<QFile*>::iterator it = m_pipeIn.begin(); it != m_pipeIn.end(); ++it) {
        (*it)->close();
        delete *it;
    }

    for(QList<QSocketNotifier*>::iterator i = m_notifier.begin(); i != m_notifier.end(); ++i) {
        delete *i;
    }

    m_pipeIn.clear();
    m_notifier.clear();

    m_running=false;
}

void KileLyxServer::removePipes()
{
    for (int i = 0; i < m_links.count(); ++i) {
        QFile::remove(m_links[i]);
    }
    for (int i = 0; i < m_pipes.count(); ++i) {
        QFile::remove(m_pipes[i]);
    }
}

void KileLyxServer::processLine(const QString &line)
{
    KILE_DEBUG_MAIN << "===void KileLyxServer::processLine(const QString " << line << ")===";

    static QRegularExpression reCite(":citation-insert:(.*)$");
    static QRegularExpression reBibtexdbadd(":bibtex-database-add:(.*)$");
    static QRegularExpression rePaste(":paste:(.*)$");

    auto match = reCite.match(line);
    if(match.hasMatch()) {
        Q_EMIT(insert(KileAction::TagData(i18n("Cite"), "\\cite{"+match.captured(1)+'}')));
        return;
    }

    match = reBibtexdbadd.match(line);
    if(match.hasMatch()) {
        Q_EMIT(insert(KileAction::TagData(i18n("Add BibTeX database"), "\\bibliography{"+ match.captured(1) + '}')));
    }

    match = rePaste.match(line);
    if (match.hasMatch()) {
        Q_EMIT(insert(KileAction::TagData(i18n("Paste"), match.captured(1))));
    }
}

void KileLyxServer::receive(int fd)
{
    if(m_file[fd]) {
        int bytesRead;
        int const size = 256;
        char buffer[size];
        if((bytesRead = read(fd, buffer, size - 1)) > 0) {
            buffer[bytesRead] = '\0'; // turn it into a c string
            QStringList cmds = QString(buffer).trimmed().split('\n');
            for(int i = 0; i < cmds.count(); ++i) {
                processLine(cmds[i]);
            }
        }
    }
}

