/*
  server.c

  $Id: server.c 70 2000-05-12 17:35:00Z enz $
*/

#if HAVE_CONFIG_H
#include <config.h>
#endif

#if TIME_WITH_SYS_TIME
#include <sys/time.h>
#include <time.h>
#else
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <time.h>
#endif
#endif

#include <stdio.h>
#include "server.h"
#include <ctype.h>
#include <signal.h>
#include <stdarg.h>
#include <sys/types.h>
#include <unistd.h>
#include "client.h"
#include "common.h"
#include "configfile.h"
#include "content.h"
#include "control.h"
#include "database.h"
#include "dynamicstring.h"
#include "fetch.h"
#include "fetchlist.h"
#include "group.h"
#include "itemlist.h"
#include "lock.h"
#include "log.h"
#include "online.h"
#include "outgoing.h"
#include "over.h"
#include "post.h"
#include "protocol.h"
#include "pseudo.h"
#include "request.h"
#include "util.h"
#include "wildmat.h"
#include "portable.h"

struct
{
    Bool running;
    int artPtr;
    Str grp; /* selected group, "" if none */
} server = { FALSE, 0, "" };

typedef struct Cmd
{
    const char *name;
    const char *syntax;
    /* Returns false, if quit cmd */
    Bool (*cmdProc)( char *arg, const struct Cmd *cmd );
}
Cmd;

static Bool doArt( char *arg, const Cmd *cmd );
static Bool doBody( char *arg, const Cmd *cmd );
static Bool doGrp( char *arg, const Cmd *cmd );
static Bool doHead( char *arg, const Cmd *cmd );
static Bool doHelp( char *arg, const Cmd *cmd );
static Bool doIhave( char *arg, const Cmd *cmd );
static Bool doLast( char *arg, const Cmd *cmd );
static Bool doList( char *arg, const Cmd *cmd );
static Bool doListgrp( char *arg, const Cmd *cmd );
static Bool doMode( char *arg, const Cmd *cmd );
static Bool doNewgrps( char *arg, const Cmd *cmd );
static Bool doNext( char *arg, const Cmd *cmd );
static Bool doPost( char *arg, const Cmd *cmd );
static Bool doSlave( char *arg, const Cmd *cmd );
static Bool doStat( char *arg, const Cmd *cmd );
static Bool doQuit( char *arg, const Cmd *cmd );
static Bool doXhdr( char *arg, const Cmd *cmd );
static Bool doXpat( char *arg, const Cmd *cmd );
static Bool doXOver( char *arg, const Cmd *cmd );
static Bool notImplemented( char *arg, const Cmd *cmd );
static void putStat( unsigned int stat, const char *fmt, ... );

Cmd commands[] =
{
    { "article", "ARTICLE [msg-id|n]", &doArt },
    { "body", "BODY [msg-id|n]", &doBody },
    { "head", "HEAD [msg-id|n]", &doHead },
    { "group", "GROUP grp", &doGrp },
    { "help", "HELP", &doHelp },
    { "ihave", "IHAVE (ignored)", &doIhave },
    { "last", "LAST", &doLast },
    { "list", "LIST [ACTIVE [pat]]|ACTIVE.TIMES [pat]|"
      "EXTENSIONS|NEWSGROUPS [pat]|OVERVIEW.FMT", &doList },
    { "listgroup", "LISTGROUP grp", &doListgrp },
    { "mode", "MODE (ignored)", &doMode },
    { "newgroups", "NEWGROUPS [xx]yymmdd hhmmss [GMT]", &doNewgrps },
    { "newnews", "NEWNEWS (not implemented)", &notImplemented },
    { "next", "NEXT", &doNext },
    { "post", "POST", &doPost },
    { "quit", "QUIT", &doQuit },
    { "slave", "SLAVE (ignored)", &doSlave },
    { "stat", "STAT [msg-id|n]", &doStat },
    { "xhdr", "XHDR over-field [m[-[n]]]", &doXhdr },
    { "xpat", "XPAT over-field m[-[n]] pat", &doXpat },
    { "xover", "XOVER [m[-[n]]]", &doXOver }
};

/*
  Notice interest in reading this group.
  Automatically subscribe if option set in config file.
*/
static void
noteInterest( void )
{
    FetchMode mode;

    Grp_setLastAccess( server.grp, time( NULL ) );
    if ( ! Grp_local ( server.grp ) && Cfg_autoSubscribe() && ! Online_true() )
    {
        Fetchlist_read();
        if ( ! Fetchlist_contains( server.grp ) )
        {
            if ( strcmp( Cfg_autoSubscribeMode(), "full" ) == 0 )
                mode = FULL;
            else if ( strcmp( Cfg_autoSubscribeMode(), "thread" ) == 0 )
                mode = THREAD;
            else
                mode = OVER;
            Fetchlist_add( server.grp, mode );
            Fetchlist_write();
            Pseudo_autoSubscribed();
        }
    }
}

static void
putStat( unsigned int stat, const char *fmt, ... )
{
    Str s, line;
    va_list ap;

    ASSERT( stat <= 999 );
    va_start( ap, fmt );
    vsnprintf( s, MAXCHAR, fmt, ap );
    va_end( ap );
    snprintf( line, MAXCHAR, "%u %s", stat, s );
    Log_dbg( "[S] %s", line );
    printf( "%s\r\n", line );
}

static void
putTxtLn( const char *fmt, ... )
{
    Str line;
    va_list ap;

    va_start( ap, fmt );
    vsnprintf( line, MAXCHAR, fmt, ap );
    va_end( ap );
    Prt_putTxtLn( line, stdout );
}

static void
putTxtBuf( const char *buf )
{
    if ( buf )
        Prt_putTxtBuf( buf, stdout );
}

static void
putEndOfTxt( void )
{
    Prt_putEndOfTxt( stdout );
}

static void
putSyntax( const Cmd *cmd )
{
    putStat( STAT_SYNTAX_ERR, "Syntax error. Usage: %s", cmd->syntax );
}

static Bool
getLn( Str line )
{
    return Prt_getLn( line, stdin );
}

static Bool
getTxtLn( Str line, Bool *err )
{
    return Prt_getTxtLn( line, err, stdin );
}

static Bool
notImplemented( char *arg, const Cmd *cmd )
{
    putStat( STAT_NO_PERMISSION, "Command not implemented" );
    return TRUE;
}

static void
checkNewArts( const char *grp )
{
    if ( ! Online_true()
         || strcmp( grp, server.grp ) == 0
         || Grp_local( grp )
         || time( NULL ) - Grp_lastAccess( server.grp ) < 1800 )
        return;
    if ( Fetch_init( Grp_server( grp ) ) )
    {
        Fetch_getNewArts( grp, OVER );
        Fetch_close();
    }
}

static void
postArts( void )
{
    Str s;

    Cfg_beginServEnum();
    while ( Cfg_nextServ( s ) )
        if ( Fetch_init( s ) )
        {
            Fetch_postArts();
            Fetch_close();
        }
}

static Bool
needsPseudoGenInfo( const char *grp )
{
    return ! ( Grp_local( grp )
	       || Fetchlist_contains( grp )
	       || Online_true() );
}

static void
readCont( const char *name )
{
    Fetchlist_read();
    Cont_read( name );
    if ( needsPseudoGenInfo( name ) )
    { 
        Pseudo_appGeneralInfo();
	/* This adds the pseudo message to the overview contents
	   but NOT to the group info. If an article gets added,
	   the group info will get updated then from the
	   contents, so the article number will be preserved.
	   Otherwise it will be lost when the content is discarded. */
    }
}

static void
changeToGrp( const char *grp )
{
    checkNewArts( grp );
    Utl_cpyStr( server.grp, grp );
    readCont( grp );
    server.artPtr = Cont_first();
}

static Bool
doGrp( char *arg, const Cmd *cmd )
{
    int first, last, numb;

    if ( arg[ 0 ] == '\0' )
        putSyntax( cmd );
    else if ( ! Grp_exists( arg ) )
        putStat( STAT_NO_SUCH_GRP, "No such group" );
    else
    {
        changeToGrp( arg );
        first = Cont_first();
        last = Cont_last();
	if ( ( first == 0 && last == 0 )
	     || first > last )
            first = last = numb = 0;
	else
	    numb = last - first + 1;
        putStat( STAT_GRP_SELECTED, "%lu %lu %lu %s selected",
                 numb, first, last, arg );
    }
    return TRUE;
}

static Bool
testGrpSelected( void )
{
    if ( *server.grp == '\0' )
    {
        putStat( STAT_NO_GRP_SELECTED, "No group selected" );
        return FALSE;
    }
    return TRUE;
}

static void
findServer( const char *msgId, Str result )
{
    const char *p, *pColon, *srv;
    Str s, grp;

    Utl_cpyStr( result, "(unknown)" );
    if ( Db_contains( msgId ) )
    {
        Utl_cpyStr( s, Db_xref( msgId ) );
        p = strtok( s, " \t" );
        if ( p )
            do
            {
                pColon = strstr( p, ":" );
                if ( pColon )
                {
                    Utl_cpyStrN( grp, p, pColon - p );
                    srv = Grp_server( grp );
                    if ( Cfg_servIsPreferential( srv, result ) )
                        Utl_cpyStr( result, srv );
                }
            }
            while ( ( p = strtok( NULL, " \t" ) ) );
    }
}

static Bool
retrieveArt( const char *msgId )
{
    Str s;

    findServer( msgId, s );    
    if ( strcmp( s, "(unknown)" ) == 0 
         || strcmp( s, GRP_LOCAL_SERVER_NAME ) == 0 )
        return FALSE;        
    if ( ! Client_connect( s ) )
        return FALSE;
    Client_retrieveArt( msgId );
    Client_disconnect();
    return TRUE;
}

static Bool
checkNumb( int numb )
{
    if ( ! testGrpSelected() )
        return FALSE;
    if ( ! Cont_validNumb( numb ) )
    {
        putStat( STAT_NO_SUCH_NUMB, "No such article" );
        return FALSE;
    }
    return TRUE;
}

/*
  Parse arguments for ARTICLE, BODY, HEAD, STAT commands.
  Return message-ID and article number (0 if unknown).
*/
static Bool
whichId( const char **msgId, int *numb, char *arg )
{
    const Over *ov;
    int n;

    if ( sscanf( arg, "%d", &n ) == 1 )
    {
        if ( ! checkNumb( n ) )
            return FALSE;
        server.artPtr = n;
        ov = Cont_get( n );
        *msgId = Ov_msgId( ov );
        *numb = n;
    }
    else if ( strcmp( arg, "" ) == 0 )
    {
        if ( ! checkNumb( server.artPtr ) )
            return FALSE;
        ov = Cont_get( server.artPtr );
        *msgId = Ov_msgId( ov );
        *numb =  server.artPtr;
    }
    else
    {
        *msgId = arg;
        *numb = 0;
    }
    if ( ! Pseudo_isGeneralInfo( *msgId ) && ! Db_contains( *msgId ) )
    {
        putStat( STAT_NO_SUCH_NUMB, "No such article" );
        return FALSE;
    }
    return TRUE;
}

static void
touchArticle( const char *msgId )
{
    int status = Db_status( msgId );
    status |= DB_INTERESTING;
    Db_setStatus( msgId, status );
    Db_updateLastAccess( msgId );
}

static void
touchReferences( const char *msgId )
{
    Str s;
    int len;
    char *p;
    const char *ref = Db_ref( msgId );

    while ( TRUE )
    {
        p = s;
        while ( *ref != '<' )
            if ( *(ref++) == '\0' )
                return;
        len = 0;
        while ( *ref != '>' )
        {
            if ( *ref == '\0' || ++len >= MAXCHAR - 1 )
                return;
            *(p++) = *(ref++);
        }
        *(p++) = '>';
        *p = '\0';
        if ( Db_contains( s ) )
            touchArticle( s );
    }
}

static void
doBodyInDb( const char *msgId )
{
    int stat;
    Str srv;

    touchArticle( msgId );
    touchReferences( msgId );
    stat = Db_status( msgId );
    if ( Online_true() && ( stat & DB_NOT_DOWNLOADED ) )
    {
        retrieveArt( msgId );
        stat = Db_status( msgId );
    }
    if ( stat & DB_RETRIEVING_FAILED )
    {
        Db_setStatus( msgId, stat & ~DB_RETRIEVING_FAILED );
        putTxtBuf( Db_body( msgId ) );
    }
    else if ( stat & DB_NOT_DOWNLOADED )
    {
        findServer( msgId, srv );
        if ( Req_contains( srv, msgId ) )
            putTxtBuf( Pseudo_alreadyMarkedBody() );
        else if ( strcmp( srv, "(unknown)" ) != 0 && 
		  strcmp( srv, GRP_LOCAL_SERVER_NAME ) != 0 && 
		  Req_add( srv, msgId ) )
            putTxtBuf( Pseudo_markedBody() );
        else
            putTxtBuf( Pseudo_markingFailedBody() );
    }
    else
        putTxtBuf( Db_body( msgId ) );
}

static Bool
doBody( char *arg, const Cmd *cmd )
{
    const char *msgId;
    int numb;
    
    if ( ! whichId( &msgId, &numb, arg ) )
        return TRUE;
    putStat( STAT_BODY_FOLLOWS, "%ld %s Body", numb, msgId );
    if ( Pseudo_isGeneralInfo( msgId ) )
        putTxtBuf( Pseudo_generalInfoBody() );
    else
        doBodyInDb( msgId );
    putEndOfTxt();
    noteInterest();
    return TRUE;
}

static void
doHeadInDb( const char *msgId )
{
    putTxtBuf( Db_header( msgId ) );
}

static Bool
doHead( char *arg, const Cmd *cmd )
{
    const char *msgId;
    int numb;
    
    if ( ! whichId( &msgId, &numb, arg ) )
        return TRUE;
    putStat( STAT_HEAD_FOLLOWS, "%ld %s Head", numb, msgId );
    if ( Pseudo_isGeneralInfo( msgId ) )
        putTxtBuf( Pseudo_generalInfoHead() );
    else
        doHeadInDb( msgId );
    putEndOfTxt();
    return TRUE;
}

static void
doArtInDb( const char *msgId )
{
    doHeadInDb( msgId );
    putTxtLn( "" );
    doBodyInDb( msgId );
}

static Bool
doArt( char *arg, const Cmd *cmd )
{
    const char *msgId;
    int numb;
    
    if ( ! whichId( &msgId, &numb, arg ) )
        return TRUE;
    putStat( STAT_ART_FOLLOWS, "%ld %s Article", numb, msgId );
    if ( Pseudo_isGeneralInfo( msgId ) )
    {
        putTxtBuf( Pseudo_generalInfoHead() );
        putTxtLn( "" );
        putTxtBuf( Pseudo_generalInfoBody() );
    }
    else
        doArtInDb( msgId );
    putEndOfTxt();
    noteInterest();
    return TRUE;
}

static Bool
doHelp( char *arg, const Cmd *cmd )
{
    unsigned int i;

    putStat( STAT_HELP_FOLLOWS, "Help" );
    putTxtBuf( "\nCommands:\n\n" );
    for ( i = 0; i < sizeof( commands ) / sizeof( commands[ 0 ] ); ++i )
        putTxtLn( "%s", commands[ i ].syntax );
    putEndOfTxt();
    return TRUE;
}

static Bool
doIhave( char *arg, const Cmd *cmd )
{
    putStat( STAT_ART_REJECTED, "Command not used" );
    return TRUE;
}

static Bool
doLast( char *arg, const Cmd *cmd )
{
    int n;

    if ( testGrpSelected() )
    {
        n = server.artPtr;
        if ( ! Cont_validNumb( n ) )
            putStat( STAT_NO_ART_SELECTED, "No article selected" );
        else
        {
            while ( ! Cont_validNumb( --n ) && n >= Cont_first() );
            if ( ! Cont_validNumb( n ) )
                putStat( STAT_NO_PREV_ART, "No previous article" );
            else
            {
                putStat( STAT_ART_RETRIEVED, "%ld %s selected",
                         n, Ov_msgId( Cont_get( n ) ) );
                server.artPtr = n;
            }
        }
    }
    return TRUE;
}

static void
printGroups( const char *pat, void (*printProc)( Str, const char* ) )
{
    Str line;
    const char *g;
    FILE *f;
    sig_t lastHandler;
    int ret;

    putStat( STAT_GRPS_FOLLOW, "Groups" );
    fflush( stdout );
    Log_dbg( "[S FLUSH]" );
    if ( Grp_exists( pat ) )
    {
        (*printProc)( line, pat );
        if ( ! Prt_putTxtLn( line, stdout ) )
            Log_err( "Writing to stdout failed." );
    }                    
    else
    {
        lastHandler = signal( SIGPIPE, SIG_IGN );
        f = popen( "sort", "w" );
        if ( f == NULL )
        {
            Log_err( "Cannot open pipe to 'sort'" );
            if ( Grp_firstGrp( &g ) )
                do
                    if ( Wld_match( g, pat ) )
                    {
                        (*printProc)( line, g );
                        if ( ! Prt_putTxtLn( line, stdout ) )
                            Log_err( "Writing to stdout failed." );
                    }
                while ( Grp_nextGrp( &g ) );
        }
        else
        {
            if ( Grp_firstGrp( &g ) )
                do
                    if ( Wld_match( g, pat ) )
                    {
                        (*printProc)( line, g );
                        if ( ! Prt_putTxtLn( line, f ) )
                        {
                            Log_err( "Writing to 'sort' pipe failed." );
                            break;
                        }                    
                    }
                while ( Grp_nextGrp( &g ) );
            ret = pclose( f );
            if ( ret != EXIT_SUCCESS )
                Log_err( "sort command returned %d", ret );
            fflush( stdout );
            Log_dbg( "[S FLUSH]" );
            signal( SIGPIPE, lastHandler );
        }
    }
    putEndOfTxt();
}

static void
printActiveTimes( Str result, const char *grp )
{
    snprintf( result, MAXCHAR, "%s %ld", grp, Grp_created( grp ) );
}

static void
doListActiveTimes( const char *pat )
{
    printGroups( pat, &printActiveTimes );
}

static void
printActive( Str result, const char *grp )
{
    int last;
    
    /* If there will be a pseudo gen info message waiting when we join
       this group, fiddle the group numbers to show it. */
    last = Grp_last( grp );
    if ( needsPseudoGenInfo( grp ) )
	last++;
    
    snprintf( result, MAXCHAR, "%s %d %d %c",
              grp, last, Grp_first( grp ), Grp_postAllow( grp ) );
}

static void
doListActive( const char *pat )
{
    /* We need to read the fetchlist so we know whether a pseudo
       gen info article needs to be faked when printing the group
       last. */
    Fetchlist_read();
    printGroups( pat, &printActive );
}

static void
printNewsgrp( Str result, const char *grp )
{
    snprintf( result, MAXCHAR, "%s %s", grp, Grp_dsc( grp ) );
}

static void
doListNewsgrps( const char *pat )
{
    printGroups( pat, &printNewsgrp );
}

static void
putGrp( const char *name )
{
    putTxtLn( "%s %lu %lu y", name, Grp_last( name ), Grp_first( name ) );
}

static void
doListOverFmt( void )
{
    putStat( STAT_GRPS_FOLLOW, "Overview format" );
    putTxtBuf( "Subject:\n"
               "From:\n"
               "Date:\n"
               "Message-ID:\n"
               "References:\n"
               "Bytes:\n"
               "Lines:\n" );
    putEndOfTxt();
}

static void
doListExtensions( void )
{
    putStat( STAT_CMD_OK, "Extensions" );
    putTxtBuf( " LISTGROUP\n"
               " XOVER\n" );
    putEndOfTxt();    
}

static Bool
doList( char *line, const Cmd *cmd )
{
    Str s, arg;
    const char *pat;

    if ( sscanf( line, "%s", s ) != 1 )
        doListActive( "*" );
    else
    {
        Utl_toLower( s );
        strcpy( arg, Utl_restOfLn( line, 1 ) );
        pat = Utl_stripWhiteSpace( arg );
        if ( pat[ 0 ] == '\0' )
            pat = "*";
        if ( strcmp( "active", s ) == 0 )
            doListActive( pat );
        else if ( strcmp( "overview.fmt", s ) == 0 )
            doListOverFmt();
        else if ( strcmp( "newsgroups", s ) == 0 )
            doListNewsgrps( pat );
        else if ( strcmp( "active.times", s ) == 0 )
            doListActiveTimes( pat );
        else if ( strcmp( "extensions", s ) == 0 )
            doListExtensions();
        else
            putSyntax( cmd );
    }
    return TRUE;
}

static Bool
doListgrp( char *arg, const Cmd *cmd )
{
    const Over *ov;
    int first, last, i;

    if ( ! Grp_exists( arg ) )
        putStat( STAT_NO_SUCH_GRP, "No such group" );
    else
    {
        changeToGrp( arg );
        first = Cont_first();
        last = Cont_last();
        putStat( STAT_GRP_SELECTED, "Article list" );
        for ( i = first; i <= last; ++i )
            if ( ( ov = Cont_get( i ) ) )
                putTxtLn( "%lu", i );
        putEndOfTxt();
    }
    return TRUE;
}

static Bool
doMode( char *arg, const Cmd *cmd )
{
    putStat( STAT_READY_POST_ALLOW, "Ok" );
    return TRUE;
}

static unsigned long
getTimeInSeconds( unsigned int year, unsigned int mon, unsigned int day,
                  unsigned int hour, unsigned int min, unsigned int sec )
{
    struct tm t;

    memset( &t, 0, sizeof( t ) );
    t.tm_year = year - 1900;
    t.tm_mon = mon - 1;
    t.tm_mday = day;
    t.tm_hour = hour;
    t.tm_min = min;
    t.tm_sec = sec;
    return mktime( &t );
}


static Bool
doNewgrps( char *arg, const Cmd *cmd )
{
    time_t t, now, lastUpdate;
    unsigned int year, mon, day, hour, min, sec, cent, len;
    const char *g;
    Str date, timeofday, file;

    if ( sscanf( arg, "%s %s", date, timeofday ) != 2 ) 
    {
        putSyntax( cmd );
        return TRUE;
    }
    len = strlen( date );
    switch ( len )
    {
    case 6:
        if ( sscanf( date, "%2u%2u%2u", &year, &mon, &day ) != 3 )
        {
            putSyntax( cmd );
            return TRUE;
        }
        now = time( NULL );
        cent = 1900;
        while ( now > getTimeInSeconds( cent + 100, 1, 1, 0, 0, 0 ) )
            cent += 100;
        year += cent;
        break;
    case 8:
        if ( sscanf( date, "%4u%2u%2u", &year, &mon, &day ) != 3 )
        {
            putSyntax( cmd );
            return TRUE;
        }
        break;
    default:
        putSyntax( cmd );
        return TRUE;
    }
    if ( sscanf( timeofday, "%2u%2u%2u", &hour, &min, &sec ) != 3 )
    {
        putSyntax( cmd );
        return TRUE;
    }
    if ( year < 1970 || mon == 0 || mon > 12 || day == 0 || day > 31
         || hour > 23 || min > 59 || sec > 60 )
    {
        putSyntax( cmd );
        return TRUE;
    }
    snprintf( file, MAXCHAR, "%s/groupinfo.lastupdate", Cfg_spoolDir() );
    t = getTimeInSeconds( year, mon, day, hour, min, sec );
    putStat( STAT_NEW_GRP_FOLLOW, "New groups since %s", arg );

    if ( ! Utl_getStamp( &lastUpdate, file ) || t <= lastUpdate )
    {
        if ( Grp_firstGrp( &g ) )
            do
                if ( Grp_created( g ) > t )
                    putGrp( g );
            while ( Grp_nextGrp( &g ) );
    }
    putEndOfTxt();
    return TRUE;
}

static Bool
doNext( char *arg, const Cmd *cmd )
{
    int n;

    if ( testGrpSelected() )
    {
        n = server.artPtr;
        if ( ! Cont_validNumb( n ) )
            putStat( STAT_NO_ART_SELECTED, "No article selected" );
        else
        {
            while ( ! Cont_validNumb( ++n ) && n <= Cont_last() );
            if ( ! Cont_validNumb( n ) )
                putStat( STAT_NO_NEXT_ART, "No next article" );
            else
            {
                putStat( STAT_ART_RETRIEVED, "%ld %s selected",
                         n, Ov_msgId( Cont_get( n ) ) );
                server.artPtr = n;
            }
        }
    }
    return TRUE;
}

/* Cancel and return TRUE if need to send cancel message on to server. */
static Bool
controlCancel( const char *cancelId )
{
    return ( Ctrl_cancel( cancelId ) == CANCEL_NEEDS_MSG );
}

/*
  It's a control message. Currently we only know about 'cancel'
  messages; others are passed on for outside groups, and logged
  as ignored for local groups.
 */
static Bool
handleControl( ItemList *control, ItemList *newsgroups,
	       const char *msgId, const DynStr *art )
{
    const char *grp;
    const char *op;
    Bool err = FALSE;
    Bool localDone = FALSE;

    op = Itl_first( control );
    if ( op == NULL )
    {
	Log_err( "Malformed control line." );
	return TRUE;
    }
    else if ( strcasecmp( op, "cancel" ) == 0 )
    {
	if ( controlCancel( Itl_next( control ) ) )
	    localDone = TRUE;
	else
	    return err;
    }

    /* Pass on for outside groups. */
    for( grp = Itl_first( newsgroups );
	 grp != NULL;
	 grp = Itl_next( newsgroups ) )
    {
	if ( Grp_exists( grp ) && ! Grp_local( grp ) )
	{
	    if ( ! Out_add( Grp_server( grp ), msgId, art ) )
	    {
		Log_err( "Cannot add posted article to outgoing directory" );
		err = TRUE;
	    }
	    break;
	}
    }

    if ( localDone )
	return err;

    /* Log 'can't do' for internal groups. */
    for( grp = Itl_first( newsgroups );
	 grp != NULL;
	 grp = Itl_next( newsgroups ) )
    {
	if ( Grp_exists( grp ) && Grp_local( grp ) )
	    Log_inf( "Ignoring control '%s' for '%s'.", op, grp );
    }

    return err;
}

static Bool
postArticle( ItemList *newsgroups, const char *msgId, const DynStr *art )
{
    const char *grp;
    Bool err;
    Bool oneLocal;

    err = oneLocal = FALSE;

    /* Run round first doing all local groups. */ 
    for( grp = Itl_first( newsgroups );
	 grp != NULL;
	 grp = Itl_next( newsgroups ) )
    {
	if ( Grp_local( grp ) )
	{
	    if ( ! oneLocal )
	    {
		if ( ! Post_open( DynStr_str( art ) ) )
		{
		    err = TRUE;
		    break;
		}
		else
		    oneLocal = TRUE;
	    }

	    if ( ! Post_add( grp ) )
		err = TRUE;
	}
    }
    if ( oneLocal )
	Post_close();

    /* Now look for a valid external group. */
    for( grp = Itl_first( newsgroups );
	 grp != NULL;
	 grp = Itl_next( newsgroups ) )
    {
	if ( Grp_exists( grp ) && ! Grp_local( grp ) )
	{
	    if ( ! Out_add( Grp_server( grp ), msgId, art ) )
	    {
		Log_err( "Cannot add posted article to outgoing directory" );
		err = TRUE;
	    }
	    break;
	}
    }

    return err;
}

static Bool
doPost( char *arg, const Cmd *cmd )
{
    Bool err, replyToFound, dateFound, inHeader;
    DynStr *s;
    Str line, field, val, msgId, from;
    const char* p;
    ItemList * newsgroups, *control;

    /*
      Get article and make following changes to the header:
      - add/replace/cut Message-ID depending on config options
      - add Reply-To with content of From, if missing
      (some providers overwrite From field)
      - rename X-Sender header to X-NOFFLE-X-Sender
      (some providers want to insert their own X-Sender)

      For doing this, it is not necessary to parse multiple-line
      headers.
    */
    putStat( STAT_SEND_ART, "Continue (end with period)" );
    fflush( stdout );
    Log_dbg( "[S FLUSH]" );
    s = new_DynStr( 10000 );
    msgId[ 0 ] = '\0';
    from[ 0 ] = '\0';
    newsgroups = control = NULL;
    replyToFound = dateFound = FALSE;
    inHeader = TRUE;
    while ( getTxtLn( line, &err ) )
    {
        if ( inHeader )
        {
            p = Utl_stripWhiteSpace( line );
            if ( *p == '\0' )
            {
                inHeader = FALSE;
                if ( from[ 0 ] == '\0' )
                    Log_err( "Posted message has no From field" );
                if ( ! Cfg_removeMsgId() )
                {
                    if ( Cfg_replaceMsgId() )
                    {
                        Prt_genMsgId( msgId, from, "NOFFLE" );
                        Log_dbg( "Replacing Message-ID with '%s'", msgId );
                    }
                    else if ( msgId[ 0 ] == '\0' )
                    {
                        Prt_genMsgId( msgId, from, "NOFFLE" );

                        Log_inf( "Adding missing Message-ID '%s'", msgId );
                    }
                    else if ( ! Prt_isValidMsgId( msgId ) )
                    {
                        Log_ntc( "Replacing invalid Message-ID with '%s'",
                                 msgId );
                        Prt_genMsgId( msgId, from, "NOFFLE" );
                    }
                    DynStr_app( s, "Message-ID: " );
                    DynStr_appLn( s, msgId );
                }
                if ( ! replyToFound && from[ 0 ] != '\0' )
                {
                    Log_dbg( "Adding Reply-To field to posted message." );
                    DynStr_app( s, "Reply-To: " );
                    DynStr_appLn( s, from );
                }
		if ( ! dateFound )
		{
		    time_t t;

		    time( &t );
		    Utl_rfc822Date( t, val );
		    DynStr_app( s, "Date: " );
		    DynStr_appLn( s, val );
		}
                DynStr_appLn( s, p );
            }
            else if ( Prt_getField( field, val, p ) )
            {
                if ( strcmp( field, "message-id" ) == 0 )
                    strcpy( msgId, val );
                else if ( strcmp( field, "from" ) == 0 )
                {
                    strcpy( from, val );
                    DynStr_appLn( s, p );
                }
                else if ( strcmp( field, "newsgroups" ) == 0 )
                {
		    Utl_toLower( val );
		    newsgroups = new_Itl ( val, " ," );
                    DynStr_appLn( s, p );
                }
                else if ( strcmp( field, "control" ) == 0 )
                {
		    control = new_Itl ( val, " " );
                    DynStr_appLn( s, p );
                }
                else if ( strcmp( field, "reply-to" ) == 0 )
                {
                    replyToFound = TRUE;
                    DynStr_appLn( s, p );
                }
                else if ( strcmp( field, "date" ) == 0 )
                {
                    dateFound = TRUE;
                    DynStr_appLn( s, p );
                }
                else if ( strcmp( field, "x-sender" ) == 0 )
                {
                    DynStr_app( s, "X-NOFFLE-X-Sender: " );
                    DynStr_appLn( s, val );
                }
                else
                    DynStr_appLn( s, p );
            }
            else
                DynStr_appLn( s, line );
        }
        else
            DynStr_appLn( s, line );
    }
    if ( inHeader )
        Log_err( "Posted message has no body" );
    if ( ! err )
    {
        if ( newsgroups == NULL || Itl_count( newsgroups ) == 0 )
        {
            Log_err( "Posted message has no valid Newsgroups header field" );
            err = TRUE;
        }
        else
	{
	    const char *grp;
	    Bool knownGrp = FALSE;
	    Bool postAllowedGrp = FALSE;

	    /* Check at least one group is known. */
	    for( grp = Itl_first( newsgroups );
		 grp != NULL;
		 grp = Itl_next( newsgroups ) )
	    {
		if ( Grp_exists( grp ) )
		{
		    knownGrp = TRUE;
		    switch( Grp_postAllow( grp ) )
		    {
		    case 'n':
			break;
		    case 'm':
			/* Can't post to moderated local groups. */
			postAllowedGrp = ! Grp_local( grp );
			break;
		    default:
			postAllowedGrp = TRUE;
		    }
		    if ( postAllowedGrp )
			break;
		}
	    }
	    
	    if ( ! knownGrp )
	    {

		Log_err( "No known group in Newsgroups header field" );
		err = TRUE;
	    }
	    else if ( ! postAllowedGrp )
	    {

		Log_err( "No group permits posting" );
		err = TRUE;
	    }
	    else
	    {
		err = ( control == NULL )
		    ? postArticle( newsgroups, msgId, s )
		    : handleControl( control, newsgroups, msgId, s );
	    }	    
	}
    }
    if ( err )
        putStat( STAT_POST_FAILED, "Posting failed" );
    else
    {
        putStat( STAT_POST_OK, "Message posted" );
        if ( Online_true() )
            postArts();
    }
    del_Itl( newsgroups );
    del_Itl( control );
    del_DynStr( s );
    return TRUE;
}

static void
parseRange( const char *s, int *first, int *last, int *numb )
{
    int r, i;
    char* p;
    Str t;

    Utl_cpyStr( t, s );
    p = Utl_stripWhiteSpace( t );
    r = sscanf( p, "%d-%d", first, last );
    if ( r < 1 )
    {
        *first = server.artPtr;
        *last = server.artPtr;
    }
    else if ( r == 1 )
    {
        if ( p[ strlen( p ) - 1 ] == '-' )
            *last = Cont_last();
        else
            *last = *first;
    }    
    if ( *first < Cont_first() )
        *first = Cont_first();
    if ( *last > Cont_last() )
        *last = Cont_last();
    if ( *first > Cont_last() ||  *last < Cont_first() )
        *last = *first - 1;
    *numb = 0;
    for ( i = *first; i <= *last; ++i )
        if ( Cont_validNumb( i ) )
            ++(*numb);
}

/*
  Note this only handles a subset of headers. But they are all
  the headers any newsreader should need to work properly.

  That last sentence will at some stage be proved wrong.
 */
static Bool
doXhdr( char *arg, const Cmd *cmd )
{
    int first, last, i, n, numb;
    enum { SUBJ, FROM, DATE, MSG_ID, REF, BYTES, LINES, XREF } what;
    const char *p, *msgId;
    const Over *ov;
    Str whatStr;

    if ( ! testGrpSelected() )
        return TRUE;
    if ( sscanf( arg, "%s", whatStr ) != 1 )
    {
        putSyntax( cmd );
        return TRUE;
    }
    Utl_toLower( whatStr );
    if ( strcmp( whatStr, "subject" ) == 0 )
        what = SUBJ;
    else if ( strcmp( whatStr, "from" ) == 0 )
        what = FROM;
    else if ( strcmp( whatStr, "date" ) == 0 )
        what = DATE;
    else if ( strcmp( whatStr, "message-id" ) == 0 )
        what = MSG_ID;
    else if ( strcmp( whatStr, "references" ) == 0 )
        what = REF;
    else if ( strcmp( whatStr, "bytes" ) == 0 )
        what = BYTES;
    else if ( strcmp( whatStr, "lines" ) == 0 )
        what = LINES;
    else if ( strcmp( whatStr, "xref" ) == 0 )
        what = XREF;
    else
    {
        putStat( STAT_HEAD_FOLLOWS, "Unknown header (empty list follows)" );
        putEndOfTxt();
        return TRUE;
    }
    p = Utl_restOfLn( arg, 1 );
    if ( p[ 0 ] == '<' )
    {
	first = last = Cont_find( p );
	if ( first < 0 )
	    numb = 0;
    }
    else
	parseRange( p, &first, &last, &numb );
    if ( numb == 0 )
        putStat( STAT_NO_ART_SELECTED, "No articles selected" );
    else
    {
        putStat( STAT_HEAD_FOLLOWS, "%s header %lu-%lu",
                 whatStr, first, last ) ;
        for ( i = first; i <= last; ++i )
            if ( ( ov = Cont_get( i ) ) )
            {
                n = Ov_numb( ov );
                switch ( what )
                {
                case SUBJ:
                    putTxtLn( "%lu %s", n, Ov_subj( ov ) );
                    break;
                case FROM:
                    putTxtLn( "%lu %s", n, Ov_from( ov ) );
                    break;
                case DATE:
                    putTxtLn( "%lu %s", n, Ov_date( ov ) );
                    break;
                case MSG_ID:
                    putTxtLn( "%lu %s", n, Ov_msgId( ov ) );
                    break;
                case REF:
                    putTxtLn( "%lu %s", n, Ov_ref( ov ) );
                    break;
                case BYTES:
                    putTxtLn( "%lu %d", n, Ov_bytes( ov ) );
                    break;
                case LINES:
                    putTxtLn( "%lu %d", n, Ov_lines( ov ) );
                    break;
		case XREF:
		    msgId = Ov_msgId( ov );
		    if ( Pseudo_isGeneralInfo( msgId ) )
			putTxtLn( "%lu %s:%lu", n, server.grp, n );
		    else
			putTxtLn( "%lu %s", n, Db_xref( msgId ) );
		    break;
                default:
                    ASSERT( FALSE );
                }
            }
        putEndOfTxt();
    }
    return TRUE;
}

static Bool
doXpat( char *arg, const Cmd *cmd )
{
    int first, last, i, n;
    enum { SUBJ, FROM, DATE, MSG_ID, REF } what;
    const Over *ov;
    Str whatStr, pat;

    if ( ! testGrpSelected() )
        return TRUE;
    if ( sscanf( arg, "%s %d-%d %s", whatStr, &first, &last, pat ) != 4 )
    {
        if ( sscanf( arg, "%s %d- %s", whatStr, &first, pat ) == 3 )
            last = Cont_last();
        else if ( sscanf( arg, "%s %d %s", whatStr, &first, pat ) == 3 )
            last = first;
        else
        {
            putSyntax( cmd );
            return TRUE;
        }
    }
    Utl_toLower( whatStr );
    if ( strcmp( whatStr, "subject" ) == 0 )
        what = SUBJ;
    else if ( strcmp( whatStr, "from" ) == 0 )
        what = FROM;
    else if ( strcmp( whatStr, "date" ) == 0 )
        what = DATE;
    else if ( strcmp( whatStr, "message-id" ) == 0 )
        what = MSG_ID;
    else if ( strcmp( whatStr, "references" ) == 0 )
        what = REF;
    else
    {
        putStat( STAT_HEAD_FOLLOWS, "invalid header (empty list follows)" );
        putEndOfTxt();
        return TRUE;
    }
    putStat( STAT_HEAD_FOLLOWS, "header" ) ;
    for ( i = first; i <= last; ++i )
        if ( ( ov = Cont_get( i ) ) )
        {
            n = Ov_numb( ov );
            switch ( what )
            {
            case SUBJ:
                if ( Wld_match( Ov_subj( ov ), pat ) )
                     putTxtLn( "%lu %s", n, Ov_subj( ov ) );
                break;
            case FROM:
                if ( Wld_match( Ov_from( ov ), pat ) )
                    putTxtLn( "%lu %s", n, Ov_from( ov ) );
                break;
            case DATE:
                if ( Wld_match( Ov_date( ov ), pat ) )
                    putTxtLn( "%lu %s", n, Ov_date( ov ) );
                break;
            case MSG_ID:
                if ( Wld_match( Ov_msgId( ov ), pat ) )
                    putTxtLn( "%lu %s", n, Ov_msgId( ov ) );
                break;
            case REF:
                if ( Wld_match( Ov_ref( ov ), pat ) )
                    putTxtLn( "%lu %s", n, Ov_ref( ov ) );
                break;
            default:
                ASSERT( FALSE );
            }
        }
    putEndOfTxt();
    return TRUE;
}

static Bool
doSlave( char *arg, const Cmd *cmd )
{
    putStat( STAT_CMD_OK, "Ok" );
    return TRUE;
}

static Bool
doStat( char *arg, const Cmd *cmd )
{
    const char *msgId;
    int numb;
    
    if ( ! whichId( &msgId, &numb, arg ) )
        return TRUE;
    if ( numb > 0 )
        putStat( STAT_ART_RETRIEVED, "%ld %s selected",
                 numb, msgId );
    else
        putStat( STAT_ART_RETRIEVED, "0 %s selected", msgId );
    return TRUE;
}

static Bool
doQuit( char *arg, const Cmd *cmd )
{
    putStat( STAT_GOODBYE, "Goodbye" );
    return FALSE;
}

static Bool
doXOver( char *arg, const Cmd *cmd )
{
    int first, last, i, n;
    const Over *ov;

    if ( ! testGrpSelected() )
        return TRUE;
    parseRange( arg, &first, &last, &n );
    if ( n == 0 )
	first = last = server.artPtr;
    putStat( STAT_OVERS_FOLLOW, "Overview %ld-%ld", first, last );
    for ( i = first; i <= last; ++i )
	if ( ( ov = Cont_get( i ) ) )
	    putTxtLn( "%lu\t%s\t%s\t%s\t%s\t%s\t%d\t%d\t",
		      Ov_numb( ov ), Ov_subj( ov ), Ov_from( ov ),
		      Ov_date( ov ), Ov_msgId( ov ), Ov_ref( ov ),
		      Ov_bytes( ov ), Ov_lines( ov ) );
    putEndOfTxt();
    return TRUE;
}

static void
putFatal( const char *fmt, ... )
{
    va_list ap;
    Str s;

    va_start( ap, fmt );
    vsnprintf( s, MAXCHAR, fmt, ap );
    va_end( ap );
    Log_err( s );
    putStat( STAT_PROGRAM_FAULT, "%s", s );
    fflush( stdout );
    Log_dbg( "[S FLUSH]" );
}

/* Parse line, execute command and return FALSE, if it was the quit command. */
static Bool
parseAndExecute( Str line )
{
    unsigned int i, n;
    Cmd *c;
    Str s, arg;
    Bool ret;

    if ( sscanf( line, "%s", s ) == 1 )
    {
        Utl_toLower( s );
        strcpy( arg, Utl_restOfLn( line, 1 ) );
        n = sizeof( commands ) / sizeof( commands[ 0 ] );
        for ( i = 0, c = commands; i < n; ++i, ++c )
            if ( strcmp( c->name, s ) == 0 )
            {
                ret = c->cmdProc( Utl_stripWhiteSpace( arg ), c );
                fflush( stdout );
                Log_dbg( "[S FLUSH]" );
                return ret;
            }
    }
    putStat( STAT_NO_SUCH_CMD, "Command not recognized" );
    fflush( stdout );
    Log_dbg( "[S FLUSH]" );
    return TRUE;
}

static void
putWelcome( void )
{
    putStat( STAT_READY_POST_ALLOW, "NNTP server NOFFLE %s",
             Cfg_version() );
    fflush( stdout );
    Log_dbg( "[S FLUSH]" );
}

static Bool
initServer( void )
{
    ASSERT( ! server.running );
    if ( ! Lock_openDatabases() )
      return FALSE;
    server.running = TRUE;
    return TRUE;
}

static void
closeServer( void )
{
    ASSERT( server.running );
    server.running = FALSE;
    Lock_closeDatabases();
}

void
Server_run( void )
{
    Bool done;
    int r;
    Str line;
    struct timeval timeOut;
    fd_set readSet;

    putWelcome();
    done = FALSE;
    while ( ! done )
    {
        FD_ZERO( &readSet );
        FD_SET( STDIN_FILENO, &readSet );
        /* Never hold lock more than 5 seconds (empirically good value,
           avoids to close/open databases, if clients sends several
           commands, but releases the lock often enough, for allowing
           multiple persons to read news at the same time) */
        timeOut.tv_sec = 5;
        timeOut.tv_usec = 0;
        r = select( STDIN_FILENO + 1, &readSet, NULL, NULL, &timeOut );
        if ( r < 0 )
            done = TRUE;
        else if ( r == 0 )
        {
            if ( server.running )
                closeServer();
        }
        else /* ( r > 0 ) */
        {
            if ( ! server.running )
            {
                if ( ! initServer() )
                {
                    putFatal( "Cannot init server" );
                    done = TRUE;
                }
            }
            if ( ! getLn( line ) )
            {
                Log_inf( "Client disconnected. Terminating." );
                done = TRUE;
            }
            else if ( ! parseAndExecute( line ) )
                done = TRUE;
        }
    }
    if ( server.running )
        closeServer();
}