package run_program; # $Id$

use diagnostics;
use strict;
use c;

use MDK::Common;
use log;

1;

sub run_or_die {
    my ($name, @args) = @_;
    run($name, @args) or die "$name failed\n";
}
sub rooted_or_die {
    my ($root, $name, @args) = @_;
    rooted($root, $name, @args) or die "$name failed\n";
}

sub get_stdout {
    my ($name, @args) = @_;
    my @r;
    run($name, '>', \@r, @args) or return;
    wantarray() ? @r : join('', @r);
}
sub rooted_get_stdout {
    my ($root, $name, @args) = @_;
    my @r;
    rooted($root, $name, '>', \@r, @args) or return;
    wantarray() ? @r : join('', @r);
}

sub run { raw({}, @_) }

sub rooted {
    my ($root, $name, @args) = @_;
    raw({ root => $root }, $name, @args);
}

sub raw {
    my ($options, $name, @args) = @_;
    my $root = $options->{root} || '';
    my $real_name = ref($name) ? $name->[0] : $name;

    my ($stdout_raw, $stdout_mode, $stderr_raw, $stderr_mode);
    ($stdout_mode, $stdout_raw, @args) = @args if $args[0] =~ /^>>?$/;
    ($stderr_mode, $stderr_raw, @args) = @args if $args[0] =~ /^2>>?$/;

    log::l("running: $real_name @args" . ($root ? " with root $root" : ""));

    return 1 if $root && $<;

    $root ? ($root .= '/') : ($root = '');
    if (!$root && !$::isStandalone) {
	require install_any;
	install_any::check_prog($real_name) if $real_name !~ /\|/;
    }
    
    $ENV{HOME} || $::isInstall or $ENV{HOME} = '/root';
    my $tmpdir = sub {
	my $dir = "$ENV{HOME}/tmp";
	-d $dir or mkdir($dir, 0700);
	$dir;
    };
    my $stdout = $stdout_raw && (ref($stdout_raw) ? $tmpdir->() . "/.drakx-stdout.$$" : "$root$stdout_raw");
    my $stderr = $stderr_raw && (ref($stderr_raw) ? $tmpdir->() . "/.drakx-stderr.$$" : "$root$stderr_raw");

    if (my $pid = fork()) {
	if ($options->{detach}) {
	    $pid;
	} else {
	    my $ok;
	    eval {
		local $SIG{ALRM} = sub { die "ALARM" };
		alarm($options->{timeout} || 10 * 60);
		waitpid $pid, 0;
		$ok = $? == 0;
		alarm 0;
	    };
	    if ($@) {
		log::l("ERROR: killing runaway process (process=$real_name, pid=$pid, args=@args, error=$@)");
		kill 9, $pid;
		return;
	    }

	    if ($stdout_raw && ref($stdout_raw)) {	    
		if (ref($stdout_raw) eq 'ARRAY') { 
		    @$stdout_raw = cat_($stdout);
		} else { 
		    $$stdout_raw = cat_($stdout);
		}
		unlink $stdout;
	    }
	    if ($stderr_raw && ref($stderr_raw)) {
		if (ref($stderr_raw) eq 'ARRAY') { 
		    @$stderr_raw = cat_($stderr);
		} else { 
		    $$stderr_raw = cat_($stderr);
		}
		unlink $stderr;
	    }
	    $ok;
	}
    } else {
	if ($stderr && $stderr eq 'STDERR') {
	} elsif ($stderr) {
	    $stderr_mode =~ s/2//;
	    open STDERR, "$stderr_mode $stderr" or die "run_program can't output in $stderr (mode `$stderr_mode')";
	} elsif ($::isInstall) {
	    open STDERR, ">> /tmp/ddebug.log" or open STDOUT, ">> /dev/tty7" or die "run_program can't log, give me access to /tmp/ddebug.log";
	}
	if ($stdout && $stdout eq 'STDOUT') {
	} elsif ($stdout) {
	    open STDOUT, "$stdout_mode $stdout" or die "run_program can't output in $stdout (mode `$stdout_mode')";
	} elsif ($::isInstall) {
	    open STDOUT, ">> /tmp/ddebug.log" or open STDOUT, ">> /dev/tty7" or die "run_program can't log, give me access to /tmp/ddebug.log";
	}

	$root and chroot $root;
	chdir "/";

	my $ok = ref $name ? do {
	    exec { $name->[0] } $name->[1], @args;
	} : do {
	    exec $name, @args;
	};
	if (!$ok) {
	    log::l("exec of $real_name failed: $!");
	    c::_exit(128);
	}
    }

}

# run in background a sub that give back data through STDOUT a la run_program::get_stdout but w/ arbitrary perl code instead of external program
package bg_command;

sub new {
    my ($class, $sub) = @_;
    my $o = bless {}, $class;
    if ($o->{pid} = open(my $fd, "-|")) {
        $o->{fd} = $fd;
        $o;
    } else {
        $sub->();
        c::_exit(0);
    }
}

sub DESTROY {
    my ($o) = @_;
    close $o->{fd} or warn "kid exited $?";
    waitpid $o->{pid}, 0;
}

1;