/****************************************************************************
**
** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtAddOn.JsonDb module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include <QtCore>
#include <QAbstractSocket>
#include <iostream>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <sys/resource.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

#include "jsondbpartitionglobal.h"
#include "jsondbsettings.h"
#include "jsondbsignals.h"
#include "dbserver.h"

#ifdef USE_SYSTEMD
#include <systemd/sd-daemon.h>
#endif

QString progname;

QT_USE_NAMESPACE_JSONDB_PARTITION

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

void daemonize()
{
    int i = fork();
    if (i < 0) exit(1); // Fork error
    if (i > 0) exit(0); // Parent exits

    ::setsid();  // Create a new process group

    /*
    for (i = ::getdtablesize() ; i > 0 ; i-- )
        ::close(i);   // Close all file descriptors
    i = ::open("/dev/null", O_RDWR); // Stdin
    ::dup(i);  // stdout
    ::dup(i);  // stderr
    */
    ::close(0);
    ::open("/dev/null", O_RDONLY);  // Stdin

//    ::umask(027);
    // ::chdir("/foo");

    QString pidfile = QString("/var/run/%1.pid").arg(QFileInfo(progname).fileName());
    int lfp = ::open(qPrintable(pidfile), O_RDWR|O_CREAT, 0640);
    if (lfp<0)
        qFatal("Cannot open pidfile %s\n", qPrintable(pidfile));
    if (lockf(lfp, F_TLOCK, 0)<0)
        qFatal("Can't get a lock on %s - another instance may be running\n", qPrintable(pidfile));
    QByteArray ba = QByteArray::number(::getpid());
    ::write(lfp, ba.constData(), ba.size());
    ::close(lfp);

    ::signal(SIGCHLD,SIG_IGN);
    ::signal(SIGTSTP,SIG_IGN);
    ::signal(SIGTTOU,SIG_IGN);
    ::signal(SIGTTIN,SIG_IGN);
}

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

static void usage(const char *errorMessage = 0)
{
    using namespace std;
    if (errorMessage)
        cout << "Error: " << errorMessage << endl << endl;
    cout << "Usage: " << qPrintable(progname) << " [OPTIONS]" << endl
         << endl
#ifdef Q_OS_LINUX
         << "     -daemon             Run as a daemon process" << endl
         << "     -sigstop            Send SIGSTOP to self when ready to notify upstart" << endl
#endif
         << "     -tcpPort port       Specify a TCP port to listen on" << endl
         << "     -config-path path   Specify the path to search for partitions.json files" << endl
#ifndef QT_NO_DEBUG_OUTPUT
         << "     -debug" << endl
         << "     -performance-log    Print timings of database operations" << endl
#endif
         << "     -verbose" << endl
         << "     -verbose-errors     Print client errors" << endl
         << "     -clear              Clear the database on startup" << endl
         << "     -pid pidfilename" << endl
         << "     -compact-on-exit    Compact database before exiting" << endl
         << "     -reject-stale-updates" << endl
         << "     -validate-schemas   Validate schemas of objects on create and update" << endl
         << "     -soft-validation    Won't reject invalid objects during schema validation but will output an according error message." << endl
         << "     -enforce-access-control " << endl
         << "     -limit megabytes" << endl
         << endl;
    exit(0);
}

static FILE *logstream = 0;
void logMessageOutput(QtMsgType type, const QMessageLogContext &, const QString &msg)
{
    if (!logstream)
        return;
    switch (type) {
    case QtDebugMsg:
        fprintf(logstream, "Debug: %s\n", qPrintable(msg));
        break;
    case QtWarningMsg:
        fprintf(logstream, "Warning: %s\n", qPrintable(msg));
        break;
    case QtCriticalMsg:
        fprintf(logstream, "Critical: %s\n", qPrintable(msg));
        break;
    case QtFatalMsg:
        fprintf(logstream, "Fatal: %s\n", qPrintable(msg));
        abort();
    }
}

int main(int argc, char * argv[])
{
    QCoreApplication::setOrganizationName("Nokia");
    QCoreApplication::setOrganizationDomain("nrcc.noklab.com");
    QCoreApplication::setApplicationName("jsondb");
    QCoreApplication::setApplicationVersion("1.0");
    QString pidFileName;
    QString searchPath;
    quint16 port = 0;
    bool clear = false;
    rlim_t limit = 0;
    QString logFileName;
    QCoreApplication app(argc, argv);
    QStringList args = QCoreApplication::arguments();
    bool compactOnClose = false;
    bool detach = false;
    bool sigstop = false;

    progname = args.takeFirst();
    while (args.size()) {
        QString arg = args.at(0);
        if (!arg.startsWith("-"))
            break;
        args.removeFirst();
        if (arg == "-help") {
            usage();
        } else if (arg == "-tcpPort") {
            if (!args.size())
                usage();
            port = args.takeFirst().toInt();
        } else if (arg == "-config-path") {
            if (!args.size())
                usage("argument to -config-path is missing");
            searchPath = args.takeFirst();
            if (!QDir(searchPath).exists())
                usage("-config-path should point to a valid directory");
        } else if (arg == "-limit") {
            if (!args.size())
                usage();
            limit = args.takeFirst().toInt() * 1024*1024;
        } else if (arg == "-pid") {
            if (!args.size())
                usage();
            pidFileName = args.takeFirst();
        } else if (arg == "-compact-on-exit") {
            compactOnClose = true;
#ifndef QT_NO_DEBUG_OUTPUT
        } else if (arg == "-debug") {
            jsondbSettings->setDebug(true);
        } else if (arg == "-verbose") {
            jsondbSettings->setVerbose(true);
        } else if (arg == "-verbose-errors") {
            jsondbSettings->setVerboseErrors(true);
        } else if (arg == "-performance-log") {
            jsondbSettings->setPerformanceLog(true);
#endif
#ifdef Q_OS_LINUX
        } else if ( arg == "-daemon" ) {
            detach = true;
        } else if ( arg == "-sigstop" ) {
            sigstop = true;
#endif
        } else if (arg == "-validate-schemas") {
            jsondbSettings->setValidateSchemas(true);
        } else if (arg == "-no-validate-schemas") {
            jsondbSettings->setValidateSchemas(false);
        } else if (arg == "-soft-validation") {
            jsondbSettings->setSoftValidation(true);
        } else if (arg == "-no-soft-validation") {
            jsondbSettings->setSoftValidation(false);
        } else if (arg == "-reject-stale-updates") {
           jsondbSettings->setRejectStaleUpdates(true);
        } else if (arg == "-no-reject-stale-updates") {
            jsondbSettings->setRejectStaleUpdates(false);
        } else if (arg == "-enforce-access-control") {
            jsondbSettings->setEnforceAccessControl(true);
        } else if (arg == "-clear") {
            clear = true;
        } else if (arg == "-base-name") {
            args.removeAt(0);
            qWarning() << QStringLiteral("The -base-name argument is no longer supported");
        } else if (arg == "-dbdir") {
            args.removeAt(0);
            qWarning() << QStringLiteral("The -dbdir argument is no longer supported");
        } else if (arg == "-log-file") {
            logFileName = args.takeFirst();
        } else {
            std::cout << "Unknown argument " << qPrintable(arg) << std::endl << std::endl;
            usage();
        }
    }
    if (detach && sigstop) {
        qCritical() << "-daemon and -sigstop are incompatible";
        usage();
    }

    if (!pidFileName.isEmpty()) {
        QFile pidFile(qPrintable(pidFileName));
        pidFile.open(QIODevice::ReadWrite|QIODevice::Truncate);
        QByteArray ba = QByteArray::number(::getpid());
        pidFile.write(ba);
        pidFile.close();
    }

    // FIXME: we should eventually make this trailing argument an error
    if (args.size() == 1)
        qDebug() << "Passing the database directory as a trailing argument is no longer supported ("
                 << args.takeFirst() << ")";

    if (!args.isEmpty())
        usage();

    if (!logFileName.isEmpty()) {
        logstream = fopen(logFileName.toLocal8Bit().data(), "w");
        if (!logstream) {
            qCritical() << QString::fromLocal8Bit("Could not open '%1'").arg(logFileName);
            return errno;
        }
        ::setbuf(logstream, 0);
        qInstallMessageHandler(logMessageOutput);
    }

    DBServer server(searchPath);
    if (port)
        server.setTcpServerPort(port);
    JsonDbSignals handler;
    QObject::connect(&handler, SIGNAL(sigTERM()), &server, SLOT(sigTERM()));
    QObject::connect(&handler, SIGNAL(sigHUP()), &server, SLOT(sigHUP()));
    QObject::connect(&handler, SIGNAL(sigINT()), &server, SLOT(sigINT()));
    QObject::connect(&handler, SIGNAL(sigUSR1()), &server, SLOT(sigUSR1()));
    handler.start();

    if (limit) {
        struct rlimit rlim;
        getrlimit(RLIMIT_AS, &rlim);
        qDebug() << "getrlimit" << "RLIMIT_DATA" << rlim.rlim_cur;
        rlim.rlim_cur = limit;
        rlim.rlim_max = limit;
        int rc = setrlimit(RLIMIT_AS, &rlim);
        if (rc)
            qWarning() << "Failed to setrlimit" << errno;
    }

    server.setCompactOnClose(compactOnClose);
    if (clear)
        server.clear();

    if (!server.socket())
        return -1;

    if (!server.start())
        return -2;

    std::cout << "Ready" << std::endl << std::flush;

    if (detach)
        daemonize();
#ifdef USE_SYSTEMD
    else
        sd_notify(0, "READY=1");
#endif
#ifdef Q_OS_LINUX
    if (sigstop)
        ::kill(::getpid(), SIGSTOP);
#endif
    int result = app.exec();

    if (logstream) {
        fclose(logstream);
        logstream = NULL;
    }
    return result;
}