#!/usr/bin/perl --

use POSIX;

setup();
read_config();
read_services();
parse_query();
process_query();

sub process_query () {
    if (exists $services{$query}) {

	exec ($verbose && length $services{$query}->{'verbose'} ?
	        $services{$query}->{'verbose'} :
		$services{$query}->{'command'});
	die $!;

    }

    if ($query eq '/') {

	print ("userv fingerd on $hostname\r\n".
	       "queries supported:\r\n".
	       "\r\n".
	       "  <nothing>     list of logged on users and available services\r\n".
	       "  /             this help text\r\n".
	       "  <service>     separately advertised special finger service\r\n".
	       "  <user>        user (logged in or otherwise)\r\n".
	       "  <user>+<xtra> user-provided extended/special finger service\r\n".
	       "  /<substring>  search for user matching substring\r\n")
	    or die $!;

	return;

    }

    if (!length $query) {

	read_per_user();

	if ($verbose) {
	    print "Username Idle  Msg,tty   Login at     From\r\n" or die $!;
	}
	
	open W,"who -iw|" or die $!;
	while (<W>) {

	    m/^(\w+) +(\S) +(\S+) +(\w+ +\d+ \d\d\:\d\d) +(\S+) +(.*)$/ or die;
	    ($user, $mesg, $tty, $login, $idle, $from) = ($1,$2,$3,$4,$5,$6);
	    $mesg = $mesg =~ m/[-+]/ ? $& : '?';

	    if ($tty =~ m/\./) {
		$from =~ s/.$/$& /;
		$from.= $tty;
		$tty= '';
	    }
	    
	    $pref= exists $user_pref_list{$user}
	        ? $user_pref_list{$user} : $def_pref_list;
	    next unless $pref =~ m/^\+/;

	    $idle= '' unless $pref =~ m/i/;
	    $mesg= ' ' unless $pref =~ m/m/;
	    $tty= '' unless $pref =~ m/t/;
	    $login= '' unless $pref =~ m/l/;
	    $from= '' unless $pref =~ m/t/;
	    
	    if ($verbose) {

		printf "%-8s %-5s %s%-8s %-12s %s\r\n",
		    $user, $idle, $mesg, $tty, $login, $from
			or die $!;
	    } else {
		$users{$user}->{'pref'} = $pref;
		$users{$user}->{'mesg'}->{$mesg} = 1;
		$users{$user}->{'idle'} = min_idle($users{$user}->{'idle'}, $idle);
	    }

	}
	$!=0; close W; $? and die "$! $?";

	if (!$verbose) {
	    print "Username Idle  Msg  Name\r\n" or die $!;

	    for $user (sort keys %users) {
		$pref= $users{$user}->{'pref'};
		$name= $pref =~ m/n/ ? (getpwnam($user))[6] : '';
		$name =~ s/,.*//;
		$mesg= join('', sort keys %{ $users{$user}->{'mesg'} });
		$mesg= '+' if $mesg =~ m,\+,;
		printf "%-8s %-5s %s    %s\r\n",
		    $user, $users{$user}->{'idle'}, $mesg, $name
			or die $!;
	    }
	}

	foreach $service (sort keys %services) {
	    $desc= $services{$service}->{'desc'};
	    next unless length $desc;

	    if (!$anyservice) {
		print "\r\nService      Description\r\n" or die $!;
		$anyservice= 1;
	    }
	    
	    printf "%-12s %s\r\n", $service, $desc or die $!;
	}
	
	print "\r\nFor help, finger /\@$hostname\r\n";
	return;
	
    }

    if ($query =~ s,^/,,) {
	$query =~ s/\W/\\$&/g;
	read_per_user();

	while (($user,$passwd,$uid,$gid,$quota,$comment,$name) = getpwent) {
	    $name =~ s/,.*//;

	    $pref= exists $user_pref_search{$user}
	        ? $user_pref_search{$user}
	        : $def_pref_search;
	    next unless $pref =~ m/[uy]/;
	    $name= '' unless $pref =~ m/y/;
	    next unless query_match($user) || query_match($name);

	    if (!$found) {
		print "Username  Name\r\n" or die $!;
		$found= 1;
	    }
	    printf "%-9s %s\r\n", $user,$name or die $!;

	}

	if (!$found) {
	    print "No matches.  finger /\@$hostname for help.\r\n" or die $!;
	}

	return;
    }

    if ($query =~ s/\+.*$//) { $qsuffix= $&; }

    if (!(($user)= getpwnam($query))) {
	print "No user named \`$query'.  finger /\@$hostname for help.\r\n" or die $!;
	return;
    }

    @servcmd= length $qsuffix
	? ('finger-finger')
        : ('finger-extended',$qsuffix);
    exec 'userv','-t',300,$user,@list;
    die $!;

}

sub query_match ($) {
    my ($data) = @_;
    return $data =~ m/\b$query\b/io;
}

sub setup () {
    $progname= $0; $progname =~ s,.*/,,;
    alarm(300);

    $config= '/etc/finger-userv/config';

    if (@ARGV) { @ARGV == 1 or die; $config= $ARGV[1]; }
    $services= '/etc/userv/finger/services';
    $peruser= '/var/lib/userv/finger/prefs';
    $def_pref_list= '+m';  $list_fields= 'imtlfn';
    $def_pref_search= 'y';  $search_opts= 'nuy';
}

sub parse_query () {
    $query= <STDIN>;
    $query =~ s/\r?\n$// or die "$0: no query\n";

    $verbose = $query =~ s,^/[wW],,;
    $query =~ s/^ *//;
}

sub min_idle ($$) {
    my ($a,$b) = @_;
    return '.' if $a eq '.' || $b eq '.';
    return $b if $a eq 'old' || $a eq '';
    return $a if $b eq 'old' || $b eq '';;
    return $a le $b ? $a : $b;
}

sub read_config () {
    if (open C, "$config") {
	while (<C>) {
	    chomp; s/\s+$//; s/^\s+//;
	    if (m/^default\-pref\s+([-+][$list_fields]+)\s+([$search_opts])$/) {
		$def_pref_list= $1;
		$def_pref_search= $2;
	    } elsif (m/^hostname\s+(\S+)$/) {
		$hostname= $1;
	    } elsif (m/^prefs\-file\s+(\S.*)$/) {
		$peruser= $1;
	    } elsif (m/^services\-file\s+(\S.*)$/) {
		$services= $1;
	    } elsif (m/\S/ && !m/^\#/) {
		die;
	    }
	}
	close C or die $!;
    } elsif ($! != &ENOENT) {
	die $!;
    }

    if (!defined $hostname) {
	chomp($hostname= `hostname -f`);
	length $hostname or die $?;
    }
}

sub read_services () {
    if (open C, "$services") {
	while (<C>) {
	    chomp; s/\s+$//; s/^\s+//;
	    next if m/^\#/ || !m/\S/;
	    if (m/^service\s+(\S.*)$/) {
		$sname= $1;
		die if exists $services{$sname};
	    } elsif (m/^(desc|command|verbose)\s+(\S.*)$/) {
		die if exists $services{$sname}->{$1};
		$services{$sname}->{$1}= $2;
	    } else {
		die;
	    }
	}
	close C;
	foreach $sname (keys %services) {
	    die unless exists $services{$sname}->{'command'};
	}
    } elsif ($! != &ENOENT) {
	die $!;
    }
}

sub read_per_user () {
    if (open DL, "$peruser") {
	while (<DL>) {
	    m/^(\w+) ([-+][$list_fields]+) ([$search_opts])$/ or die;
	    $user_pref_list{$1}= $2;
	    $user_pref_search{$1}= $3;
	}
	close DL;
    } elsif ($! != &ENOENT) {
	die $!;
    }
}