#!/Utils/bin/perl

# $Id: showhtml,v 1.8 1995/08/22 14:02:35 belinfan Exp $

# a script to handle text/html documents:
#   find the Mosaic or Netscape process (or start a new one),
#   and use the corresponding remote-execution feature to have
#   it display the document.

# Author: Axel.Belinfante@cs.utwente.nl

#print stderr "testing....\n";
#foreach (keys %ENV) {
#  print stderr $_.' : '.$ENV{$_}."\n";
#}
#exit;

$mcmd_prefix = '/tmp/Mosaic.';
$home = $ENV{'HOME'};
$symlinkfile = '/tmp/showhtml'.$$.'.html';

$default_viewer = 'mosaic';

$mpidfile = $home . '/' . '.mosaicpid';
$mprefix = $home . '/' . '.mosaic';
$npidfile = $home . '/' . '.netscapepid';
$nprefix = $home . '/' . '.netscape';

$ps_opt = '-a';
(@uname) = split(' ', `uname -a`);
if ($uname[0] =~ /sunos/i && $uname[2] =~ /^4/) {
    $ps_opt = 'x';
}

($file_url, @flags) = @ARGV;
&main($file_url, @flags);

sub main {
    local($file_url, @flags) = @_;
    local($viewer) = &find_a_viewer(@flags);

    if (grep(/^-html$/, @flags)) {
	symlink($file_url, $symlinkfile);
	&do_view($symlinkfile, '', $viewer);
	sleep 10;
	unlink($symlinkfile);
    } elsif (grep(/^-url$/, @flags) || $file_url =~ /^http:/) {
        &do_view('', $file_url, $viewer);
    } else {
	&do_view($file_url, '', $viewer);
    }
}

sub find_a_viewer {
    local(@flags) = @_;
    local($mpid);
    local($npid);
    local($f);
    if (! $ENV{'DISPLAY'}) {
	$viewer = 'lynx';
    } else {
        $mpid = &find_viewer('', '', $mpidfile, '', 'Mosaic', '');
        $npid = &find_viewer('', '', $npidfile, '', 'netscape', '');
	if ($mpid || grep(/^-mosaic$/i, @flags)) {
	    $viewer = 'mosaic';
	} elsif ($npid || grep(/^-netscape$/i, @flags)) {
	    $viewer = 'netscape';
	} else {
            foreach $f (<$mprefix-*>, <$nprefix-*>) {
                $age{$f} = -M $f;
	    }
	    $last = (sort byage (keys %age))[0];
	    print STDERR "Last updated file: $last\n" if $debug;
	    if ($last =~ /^$mprefix\-/) {
	        $viewer = 'mosaic';
	    } elsif ($last =~ /^$nprefix\-/) {
	        $viewer = 'netscape';
	    } else {
	        $viewer = $default_viewer;
	    }
        }
    }
}

sub do_view {
    local($out_file, $location, $viewer) = @_;
    $viewer =~ /mosaic/i
	&& &do_view_mosaic($out_file, $location);
    $viewer =~ /netscape/i
	&& &do_view_netscape($out_file, $location);
    $viewer =~ /lynx/i
	&& &do_view_lynx($out_file, $location);
}

sub do_view_mosaic {
    local($out_file, $location) = @_;
    local($mpid) = &find_viewer($out_file, $location, $mpidfile, 'start_mosaic', 'Mosaic', 'Mosaic');
    &do_remote_mosaic($out_file, $location, $mpid) if $mpid > 0;
}

sub do_view_netscape {
    local($out_file, $location) = @_;
    local($wid) = &find_viewer($out_file, $location, $npidfile, 'start_netscape', 'netscape', 'Netscape');
    &do_remote_netscape($out_file, $location, $wid) if $wid > 0;
}

sub do_view_lynx {
    local($out_file, $location) = @_;
    if ($location) {
        print STDERR "Location: $location\n" if $debug;
	system("lynx '$location'");
    } else {
	system("lynx 'file://localhost$out_file'");
    }
}

sub start_mosaic {
    local($out_file, $location, $mpidfile) = @_;
    local($timer) = 10;
    local($url) = $out_file || $location;
    system("rm -f $mpidfile") if -r $mpidfile;
    print STDERR "starting: 'Mosaic $url &'\n";
    system("Mosaic $url &");
    sleep 10;
    while (! -r $mpidfile && $timer) {
	sleep 1;
	$timer--;
    }
}

sub do_remote_mosaic {
    local($out_file, $location, $mpid) = @_;
    open(MCMD, '>'.$mcmd_prefix.$mpid) || die "$c: cannot open mcmd file $mcmd_prefix.$mpid: $!";
    print MCMD "goto\n";
    if ($location) {
        print STDERR "Location: $location\n" if $debug;
	print MCMD $location."\n";
    } else {
	print MCMD 'file://localhost'.$out_file."\n";
    }
    close(MCMD);
    kill 'USR1', $mpid;
}

sub do_remote_netscape {
    local($out_file, $location, $wid) = @_;
    local($windowopt);
    if ($location) {
        print STDERR "Location: $location\n" if $debug;
	system("netscape $windowopt -remote 'openURL($location)'");
    } else {
	system("netscape $windowopt -remote 'openURL(file://localhost$out_file)'");
    }
}

sub start_netscape {
    local($out_file, $location, $npidfile) = @_;
    local($timer) = 10;
    local($url) = $out_file || $location;
    system("rm -f $npidfile") if -r $npidfile;
    print STDERR "starting: 'netscape $url &'\n";
    system("netscape $url &");
    sleep 10;
#    while (! -r $npidfile && $timer) {
#	sleep 1;
#	$timer--;
#    }
}

##############################################

sub find_viewer {
    local($out_file, $location, $pidfile, $starter, $program, $name) = @_;
    local($pid);
    $pid = &find_check_pid($pidfile) if -r $pidfile;
    $pid = &read_psx($program) if ! $pid;
    if (! $pid && $starter) {
        &$starter($out_file, $location, $pidfile);
	&flush_ps_cache;
        $pid = - &find_check_pid($pidfile);
        $pid = - &read_psx($program) if ! $pid;
    }
    print STDERR "Could not find pid nor start $name\n"
	unless $pid || !$starter;
    $pid;
}

sub ps_cache {
    @cached_ps = split("\n", `ps $ps_opt`) unless @cached_ps;
    return @cached_ps;
}
sub flush_ps_cache {
    @cached_ps = ();
}

sub read_psx {
    local($progname) = @_;
    local($foundpid, $rest, @mpids);
    local(@pidinfo) = grep(/$progname/, &ps_cache);
    foreach (@pidinfo) {
	print STDERR "pid output: ".$_."\n" if $debug;
        ($foundpid, $rest) = split(' ', $_, 2);
        push(@mpids, $foundpid);
    }
    @mpids = sort(@mpids);
    shift @mpids;
}

sub find_check_pid {
    local($pidfile) = @_;
    local($pid);
    if (-r $pidfile) {
        $pid = &read_pidfile($pidfile);
        $pid = &read_ps_pid($pid);
        system("rm -f $pidfile") if ! $pid;
    }
    $pid;
}

sub read_pidfile {
    local($pidfile) = @_;
    local($pid);
    open (PID, $pidfile) || die "Cannot open pid file $pidfile: $!";
    $pid = <PID>;
    chop($pid);
    close(PID);
    $pid;
}

sub read_ps_pid {
    local($pid) = @_;
    local($ok, $foundpid, $rest);
    local(@pidinfo) = grep(/^$pid/, &ps_cache);
    $ok = 0;
    foreach (@pidinfo) {
        ($foundpid, $rest) = split(' ', $_, 2);
        $ok = 1 if $foundpid == $pid;
    }
    $ok ? $pid : '';
}

sub byage { $age{$a} <=> $age{$b}; }