#!/usr/bin/perl -w

# start-engine
# derived from start-memcached
# 2003/2004 - Jay Bonci <jaybonci@debian.org>
# This script handles the parsing of the /etc/memcached.conf file
# and was originally created for the Debian distribution.
# Anyone may use this little script under the same terms as
# memcached itself.

# a bit changed it for telegram-daemon to generate config before start (Vitaly Valtman)

use POSIX qw(strftime);
use strict;

my $id = defined($ARGV[0]) ? $ARGV[0] : '';
my $idx = $id eq '' ? '' : " '$id'";
my $idl = ($id =~ /^\.(.*)$/ ? "-$1" : $id);

my $root = "";

my $params; my $etchandle; my $etcfile = "$root/etc/telegram-daemon/telegram-daemon$id.conf";

# This script assumes that engine is located at /usr/bin/engine, and
# that the pidfile is writable at /var/run/engine.pid

my $engine_pfx = "$root/usr/share/telegram-daemon/bin/";
my $pidfile = "$root/var/run/telegram-daemon$id.pid";

# If we don't get a valid logfile parameter in the /etc/engine.conf file,
# we'll just throw away all of our in-daemon output. We need to re-tie it so
# that non-bash shells will not hang on logout. Thanks to Michael Renner for 
# the tip
my $fd_reopened = "/dev/null";
$fd_reopened = "$root/var/log/telegram-daemon/telegram-daemon$idl.log" if -d "$root/var/log/telegram-daemon/";

sub handle_logfile
{
    my ($logfile) = @_;
    $logfile = "$root/var/log/telegram-daemon/$logfile" unless $logfile =~ /\//;
    $fd_reopened = $logfile;
}

sub reopen_logfile
{
    my ($logfile) = @_;
    
    open *STDERR, ">>$logfile";
    open *STDOUT, ">>$logfile";
    open *STDIN, ">>/dev/null";
    chown 239, 239, $logfile;
    $fd_reopened = $logfile;
}

sub adjust_arg
{
    my ($arg) = @_;
    if ($arg =~ /^newest:(.*)$/) {
        my @L = split /:/, $1;
        my $x = $arg;
        my $xt = 0;
        for my $y (@L) {
            my @S = stat($y);
            if (scalar @S && $S[9] > $xt) {
                $x = $y;
                $xt = $S[9];
            }
        }
        return $x;
    }
    return $arg;
}

# This is set up in place here to support other non -[a-z] directives

my $conf_directives = {
        "logfile" => \&handle_logfile,
};

my %Vars = ( 
             "execute" => "msg-search-engine",
             "work_dir"   => "$root/var/lib/telegram-daemon"
             );

my $have_c = 0;
my $have_l = 0;
my $have_u = 0;
my $have_aes = 0;

if(open $etchandle, $etcfile)
{
        foreach my $line (<$etchandle>)
        {
                $line ||= "";
                $line =~ s/\#.*//g;
                $line =~ s/\s+$//g;
                $line =~ s/^\s+//g;
                next unless $line;
                next if $line =~ /^\-[h]/;

                if($line =~ /^[^\-]/)
                {
                        my ($directive, $int, $arg) = $line =~ /^(.*?)(\s+|\s*=\s*)(.*)/; 
                        next unless $directive;
                        if (exists $conf_directives->{$directive}) {
                            $conf_directives->{$directive}->($arg);
                        } else {
                            $Vars{$directive} = $arg;
                        }
                        next;
                }

                $have_l = 1 if $line =~ /^-L\s/;
                $have_c = 1 if $line =~ /^-c\s/;
                $have_u = 1 if $line =~ /^-U\s/;
                push @$params, $line;                
        }

}else{
        $params = [];
}

push @$params, "-U telegramd" unless($have_u);
push @$params, "-L $fd_reopened" unless($have_l);
push @$params, "-c config$idl" unless($have_c);
$params = join " ", @$params;

if(-e $pidfile)
{
        open PIDHANDLE, "$pidfile";
        my $localpid = <PIDHANDLE>;
        close PIDHANDLE;

        if ($localpid && $localpid =~ /(\d+)/) { $localpid = $1; } else { $localpid = -1; }
        if (-d "/proc/$localpid")
        {
                print STDERR "telegram-daemon$idl is already running.\n"; 
                exit;                
        } else {
                print STDERR "removing stale $pidfile.\n"; 
                `rm -f $pidfile`;
        }

}

if (exists $Vars{'quit'}) {
    print STDERR "telegram-daemon$idl disabled\n";
    exit(0);
}

my $engine = $engine_pfx.$Vars{'execute'};
my $wdir = $Vars{'work_dir'};
chdir $wdir if -d $wdir;

unless (-x $engine) {
    print STDERR "executable $engine not found\n";
    exit(1);
}

unless (-d $wdir) {
    print STDERR "work directory $wdir not found\n";
    exit(1);
}

for my $x ('s', 0 .. 9) {
    if (defined($Vars{"arg$x"})) {
        $params .= " ".adjust_arg($Vars{"arg$x"});
    }
}

my $pid = fork();



if (!$pid) {
    reopen_logfile ($fd_reopened);
    chdir $wdir;
    open(my $fh, '>', "config$idl");

    my $text = <<"END_MSG"
config_directory="$wdir";
test=false;
msg_num=true;
binlog_enabled=true;
binlog="binlog$idl.bin";
pfs_enabled=true;
log_level = 0;
lua_script="script$idl.lua";
END_MSG
;
    print $fh $text;
    close $fh;
    my $t;
    $t = strftime ("%Y-%m-%d %H:%M:%S %Z", localtime);
    print STDERR "[$t] invoking telegram-daemon$idl: $engine $params\n";
    exec "$engine $params";
    exit (0);
} else {
    if (open PIDHANDLE,">$pidfile") {
        print PIDHANDLE $pid;
        close PIDHANDLE;
    } else {
        print STDERR "Can't write pidfile to $pidfile.\n";
    }
}