#!/usr/bin/perl

use strict;
use warnings;

use Fcntl qw(:flock SEEK_END);
use Getopt::Long qw(GetOptionsFromArray);
use File::Path qw(make_path);
use JSON;
use IO::File;
use String::ShellQuote 'shell_quote';

my $PROGNAME = "pve-zsync";
my $CONFIG_PATH = "/var/lib/${PROGNAME}";
my $STATE = "${CONFIG_PATH}/sync_state";
my $CRONJOBS = "/etc/cron.d/$PROGNAME";
my $PATH = "/usr/sbin";
my $PVE_DIR = "/etc/pve/local";
my $QEMU_CONF = "${PVE_DIR}/qemu-server";
my $LXC_CONF = "${PVE_DIR}/lxc";
my $PROG_PATH = "$PATH/${PROGNAME}";
my $INTERVAL = 15;
my $DEBUG;

BEGIN {
    $DEBUG = 0; # change default here. not above on declaration!
    $DEBUG ||= $ENV{ZSYNC_DEBUG};
    if ($DEBUG) {
	require Data::Dumper;
	Data::Dumper->import();
    }
}

my $IPV4OCTET = "(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])";
my $IPV4RE = "(?:(?:$IPV4OCTET\\.){3}$IPV4OCTET)";
my $IPV6H16 = "(?:[0-9a-fA-F]{1,4})";
my $IPV6LS32 = "(?:(?:$IPV4RE|$IPV6H16:$IPV6H16))";

my $IPV6RE = "(?:" .
    "(?:(?:" .                             "(?:$IPV6H16:){6})$IPV6LS32)|" .
    "(?:(?:" .                           "::(?:$IPV6H16:){5})$IPV6LS32)|" .
    "(?:(?:(?:" .              "$IPV6H16)?::(?:$IPV6H16:){4})$IPV6LS32)|" .
    "(?:(?:(?:(?:$IPV6H16:){0,1}$IPV6H16)?::(?:$IPV6H16:){3})$IPV6LS32)|" .
    "(?:(?:(?:(?:$IPV6H16:){0,2}$IPV6H16)?::(?:$IPV6H16:){2})$IPV6LS32)|" .
    "(?:(?:(?:(?:$IPV6H16:){0,3}$IPV6H16)?::(?:$IPV6H16:){1})$IPV6LS32)|" .
    "(?:(?:(?:(?:$IPV6H16:){0,4}$IPV6H16)?::" .           ")$IPV6LS32)|" .
    "(?:(?:(?:(?:$IPV6H16:){0,5}$IPV6H16)?::" .            ")$IPV6H16)|" .
    "(?:(?:(?:(?:$IPV6H16:){0,6}$IPV6H16)?::" .                    ")))";

my $HOSTv4RE0 = "(?:[\\w\\.\\-_]+|$IPV4RE)";       # hostname or ipv4 address
my $HOSTv4RE1 = "(?:$HOSTv4RE0|\\[$HOSTv4RE0\\])"; # these may be in brackets, too
my $HOSTRE = "(?:$HOSTv4RE1|\\[$IPV6RE\\])";       # ipv6 must always be in brackets
# targets are either a VMID, or a 'host:zpool/path' with 'host:' being optional
my $TARGETRE = qr!^(?:($HOSTRE):)?(\d+|(?:[\w\-_]+)(/.+)?)$!;

my $DISK_KEY_RE = qr/^(?:(?:(?:virtio|ide|scsi|sata|efidisk|mp)\d+)|rootfs): /;

my $INSTANCE_ID = get_instance_id($$);

my $command = $ARGV[0];

if (defined($command) && $command ne 'help' && $command ne 'printpod') {
    check_bin ('cstream');
    check_bin ('zfs');
    check_bin ('ssh');
    check_bin ('scp');
}

$SIG{TERM} = $SIG{QUIT} = $SIG{PIPE} = $SIG{HUP} = $SIG{KILL} = $SIG{INT} =  sub {
    die "Signaled, aborting sync: $!\n";
};

sub check_bin {
    my ($bin)  = @_;

    foreach my $p (split (/:/, $ENV{PATH})) {
	my $fn = "$p/$bin";
	if (-x $fn) {
	    return $fn;
	}
    }

    die "unable to find command '$bin'\n";
}

sub read_file {
    my ($filename, $one_line_only) = @_;

    my $fh = IO::File->new($filename, "r")
	or die "Could not open file ${filename}: $!\n";

    my $text = $one_line_only ? <$fh> : [ <$fh> ];

    close($fh);

    return $text;
}

sub cut_target_width {
    my ($path, $maxlen) = @_;
    $path =~ s@/+@/@g;

    return $path if length($path) <= $maxlen;

    return '..'.substr($path, -$maxlen+2) if $path !~ m@/@;

    $path =~ s@/([^/]+/?)$@@;
    my $tail = $1;

    if (length($tail)+3 == $maxlen) {
	return "../$tail";
    } elsif (length($tail)+2 >= $maxlen) {
	return '..'.substr($tail, -$maxlen+2)
    }

    $path =~ s@(/[^/]+)(?:/|$)@@;
    my $head = $1;
    my $both = length($head) + length($tail);
    my $remaining = $maxlen-$both-4; # -4 for "/../"

    if ($remaining < 0) {
	return substr($head, 0, $maxlen - length($tail) - 3) . "../$tail"; # -3 for "../"
    }

    substr($path, ($remaining/2), (length($path)-$remaining), '..');
    return "$head/" . $path . "/$tail";
}

sub locked {
    my ($lock_fn, $code) = @_;

    my $lock_fh = IO::File->new("> $lock_fn");

    flock($lock_fh, LOCK_EX) || die "Couldn't acquire lock - $!\n";
    my $res = eval { $code->() };
    my $err = $@;

    flock($lock_fh, LOCK_UN) || warn "Error unlocking - $!\n";
    die "$err" if $err;

    close($lock_fh);
    return $res;
}

sub get_status {
    my ($source, $name, $status) = @_;

    if ($status->{$source->{all}}->{$name}->{status}) {
	return $status;
    }

    return undef;
}

sub check_dataset_exists {
    my ($dataset, $ip, $user) = @_;

    my $cmd = [];

    if ($ip) {
	push @$cmd, 'ssh', "$user\@$ip", '--';
    }
    push @$cmd, 'zfs', 'list', '-H', '--', $dataset;
    eval {
	run_cmd($cmd);
    };

    if ($@) {
	return 0;
    }
    return 1;
}

sub create_file_system {
    my ($file_system, $ip, $user) = @_;

    my $cmd = [];

    if ($ip) {
	push @$cmd, 'ssh', "$user\@$ip", '--';
    }
    push @$cmd, 'zfs', 'create', $file_system;

    run_cmd($cmd);
}

sub parse_target {
    my ($text) = @_;

    my $errstr = "$text : is not a valid input! Use [IP:]<VMID> or [IP:]<ZFSPool>[/Path]";
    my $target = {};

    if ($text !~ $TARGETRE) {
	die "$errstr\n";
    }
    $target->{all} = $2;
    $target->{ip} = $1 if $1;
    my @parts = split('/', $2);

    $target->{ip} =~ s/^\[(.*)\]$/$1/ if $target->{ip};

    my $pool = $target->{pool} = shift(@parts);
    die "$errstr\n" if !$pool;

    if ($pool =~ m/^\d+$/) {
	$target->{vmid} = $pool;
	delete $target->{pool};
    }

    return $target if (@parts == 0);
    $target->{last_part} = pop(@parts);

    if ($target->{ip}) {
	pop(@parts);
    }
    if (@parts > 0) {
	$target->{path} = join('/', @parts);
    }

    return $target;
}

sub read_cron {

    #This is for the first use to init file;
    if (!-e $CRONJOBS) {
	my $new_fh = IO::File->new("> $CRONJOBS");
	die "Could not create $CRONJOBS: $!\n" if !$new_fh;
	close($new_fh);
	return undef;
    }

    my $text = read_file($CRONJOBS, 0);

    return encode_cron(@{$text});
}

sub parse_argv {
    my (@arg) = @_;

    my $param = {
	dest => undef,
	source => undef,
	verbose => undef,
	limit => undef,
	maxsnap => undef,
	name => undef,
	skip => undef,
	method => undef,
	source_user => undef,
	dest_user => undef,
	prepend_storage_id => undef,
	properties => undef,
	dest_config_path => undef,
    };

    my ($ret) = GetOptionsFromArray(
	\@arg,
	'dest=s' => \$param->{dest},
	'source=s' => \$param->{source},
	'verbose' => \$param->{verbose},
	'limit=i' => \$param->{limit},
	'maxsnap=i' => \$param->{maxsnap},
	'name=s' => \$param->{name},
	'skip' => \$param->{skip},
	'method=s' => \$param->{method},
	'source-user=s' => \$param->{source_user},
	'dest-user=s' => \$param->{dest_user},
	'prepend-storage-id' => \$param->{prepend_storage_id},
	'properties' => \$param->{properties},
	'dest-config-path=s' => \$param->{dest_config_path},
    );

    die "can't parse options\n" if $ret == 0;

    $param->{name} //= "default";
    $param->{maxsnap} //= 1;
    $param->{method} //= "ssh";
    $param->{source_user} //= "root";
    $param->{dest_user} //= "root";

    return $param;
}

sub add_state_to_job {
    my ($job) = @_;

    my $states = read_state();
    my $state = $states->{$job->{source}}->{$job->{name}};

    $job->{state} = $state->{state};
    $job->{lsync} = $state->{lsync};
    $job->{vm_type} = $state->{vm_type};
    $job->{instance_id} = $state->{instance_id};

    for (my $i = 0; $state->{"snap$i"}; $i++) {
	$job->{"snap$i"} = $state->{"snap$i"};
    }

    return $job;
}

sub encode_cron {
    my (@text) = @_;

    my $cfg = {};

    while (my $line = shift(@text)) {

	my @arg = split('\s', $line);
	my $param = parse_argv(@arg);

	if ($param->{source} && $param->{dest}) {
	    my $source = delete $param->{source};
	    my $name = delete $param->{name};

	    $cfg->{$source}->{$name} = $param;
	}
    }

    return $cfg;
}

sub param_to_job {
    my ($param) = @_;

    my $job = {};

    my $source = parse_target($param->{source});
    my $dest;
    $dest = parse_target($param->{dest}) if $param->{dest};

    $job->{name} = !$param->{name} ? "default" : $param->{name};
    $job->{dest} = $param->{dest} if $param->{dest};
    $job->{method} = "local" if !$dest->{ip} && !$source->{ip};
    $job->{method} = "ssh" if !$job->{method};
    $job->{limit} = $param->{limit};
    $job->{maxsnap} = $param->{maxsnap} if $param->{maxsnap};
    $job->{source} = $param->{source};
    $job->{source_user} = $param->{source_user};
    $job->{dest_user} = $param->{dest_user};
    $job->{prepend_storage_id} = !!$param->{prepend_storage_id};
    $job->{properties} = !!$param->{properties};
    $job->{dest_config_path} = $param->{dest_config_path} if $param->{dest_config_path};

    return $job;
}

sub read_state {

    if (!-e $STATE) {
	make_path $CONFIG_PATH;
	my $new_fh = IO::File->new("> $STATE");
	die "Could not create $STATE: $!\n" if !$new_fh;
	print $new_fh "{}";
	close($new_fh);
	return undef;
    }

    my $text = read_file($STATE, 1);
    return decode_json($text);
}

sub update_state {
    my ($job) = @_;

    my $text = eval { read_file($STATE, 1); };

    my $out_fh = IO::File->new("> $STATE.new");
    die "Could not open file ${STATE}.new: $!\n" if !$out_fh;

    my $states = {};
    my $state = {};
    if ($text){
	$states = decode_json($text);
	$state = $states->{$job->{source}}->{$job->{name}};
    }

    if ($job->{state} ne "del") {
	$state->{state} = $job->{state};
	$state->{lsync} = $job->{lsync};
	$state->{instance_id} = $job->{instance_id};
	$state->{vm_type} = $job->{vm_type};

	for (my $i = 0; $job->{"snap$i"} ; $i++) {
	    $state->{"snap$i"} = $job->{"snap$i"};
	}
	$states->{$job->{source}}->{$job->{name}} = $state;
    } else {

	delete $states->{$job->{source}}->{$job->{name}};
	delete $states->{$job->{source}} if !keys %{$states->{$job->{source}}};
    }

    $text = encode_json($states);
    print $out_fh $text;

    close($out_fh);
    rename "$STATE.new", $STATE;

    return $states;
}

sub update_cron {
    my ($job) = @_;

    my $updated;
    my $has_header;
    my $line_no = 0;
    my $text = "";
    my $header = "SHELL=/bin/sh\n";
    $header .= "PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin\n\n";

    my $current = read_file($CRONJOBS, 0);

    foreach my $line (@{$current}) {
	chomp($line);
	if ($line =~ m/source $job->{source} .*name $job->{name} /) {
	    $updated = 1;
	    next if $job->{state} eq "del";
	    $text .= format_job($job, $line);
	} else {
	    if (($line_no < 3) && ($line =~ /^(PATH|SHELL)/ )) {
		$has_header = 1;
	    }
	    $text .= "$line\n";
	}
	$line_no++;
    }

    if (!$has_header) {
	$text = "$header$text";
    }

    if (!$updated) {
	$text .= format_job($job);
    }
    my $new_fh = IO::File->new("> ${CRONJOBS}.new");
    die "Could not open file ${CRONJOBS}.new: $!\n" if !$new_fh;

    die "can't write to $CRONJOBS.new\n" if !print($new_fh $text);
    close ($new_fh);

    die "can't move $CRONJOBS.new: $!\n" if !rename "${CRONJOBS}.new", $CRONJOBS;
}

sub format_job {
    my ($job, $line) = @_;
    my $text = "";

    if ($job->{state} eq "stopped") {
	$text = "#";
    }
    if ($line) {
	$line =~ /^#*\s*((?:\S+\s+){4}\S+)\s+root/;
	$text .= $1;
    } else {
	$text .= "*/$INTERVAL * * * *";
    }
    $text .= " root";
    $text .= " $PROGNAME sync --source $job->{source} --dest $job->{dest}";
    $text .= " --name $job->{name} --maxsnap $job->{maxsnap}";
    $text .= " --limit $job->{limit}" if $job->{limit};
    $text .= " --method $job->{method}";
    $text .= " --verbose" if $job->{verbose};
    $text .= " --source-user $job->{source_user}";
    $text .= " --dest-user $job->{dest_user}";
    $text .= " --prepend-storage-id" if $job->{prepend_storage_id};
    $text .= " --properties" if $job->{properties};
    $text .= " --dest-config-path $job->{dest_config_path}" if $job->{dest_config_path};
    $text .= "\n";

    return $text;
}

sub list {

    my $cfg = read_cron();

    my $list = sprintf("%-25s%-25s%-10s%-20s%-6s%-5s\n" , "SOURCE", "NAME", "STATE", "LAST SYNC", "TYPE", "CON");

    my $states = read_state();
    foreach my $source (sort keys%{$cfg}) {
	foreach my $name (sort keys%{$cfg->{$source}}) {
	    $list .= sprintf("%-25s", cut_target_width($source, 25));
	    $list .= sprintf("%-25s", cut_target_width($name, 25));
	    $list .= sprintf("%-10s", $states->{$source}->{$name}->{state});
	    $list .= sprintf("%-20s", $states->{$source}->{$name}->{lsync});
	    $list .= sprintf("%-6s", defined($states->{$source}->{$name}->{vm_type}) ? $states->{$source}->{$name}->{vm_type} : "undef");
	    $list .= sprintf("%-5s\n", $cfg->{$source}->{$name}->{method});
	}
    }

    return $list;
}

sub vm_exists {
    my ($target, $user) = @_;

    return undef if !defined($target->{vmid});

    my $conf_fn = "$target->{vmid}.conf";

    if ($target->{ip}) {
	my @cmd = ('ssh', "$user\@$target->{ip}", '--', '/bin/ls');
	return "qemu" if eval { run_cmd([@cmd, "$QEMU_CONF/$conf_fn"]) };
	return "lxc" if  eval { run_cmd([@cmd, "$LXC_CONF/$conf_fn"]) };
    } else {
	return "qemu" if -f "$QEMU_CONF/$conf_fn";
	return "lxc" if -f "$LXC_CONF/$conf_fn";
    }

    return undef;
}

sub init {
    my ($param) = @_;

    locked("$CONFIG_PATH/cron_and_state.lock", sub {
	my $cfg = read_cron();

	my $job = param_to_job($param);

	$job->{state} = "ok";
	$job->{lsync} = 0;

	my $source = parse_target($param->{source});
	my $dest = parse_target($param->{dest});

	if (my $ip =  $dest->{ip}) {
	    run_cmd(['ssh-copy-id', '-i', '/root/.ssh/id_rsa.pub', "$param->{dest_user}\@$ip"]);
	}

	if (my $ip =  $source->{ip}) {
	    run_cmd(['ssh-copy-id', '-i', '/root/.ssh/id_rsa.pub', "$param->{source_user}\@$ip"]);
	}

	die "Pool $dest->{all} does not exist\n"
	    if !check_dataset_exists($dest->{all}, $dest->{ip}, $param->{dest_user});

	if (!defined($source->{vmid})) {
	    die "Pool $source->{all} does not exist\n"
		if !check_dataset_exists($source->{all}, $source->{ip}, $param->{source_user});
	}

	my $vm_type = vm_exists($source, $param->{source_user});
	$job->{vm_type} = $vm_type;
	$source->{vm_type} = $vm_type;

	die "VM $source->{vmid} doesn't exist\n" if $source->{vmid} && !$vm_type;

	die "Config already exists\n" if $cfg->{$job->{source}}->{$job->{name}};

	#check if vm has zfs disks if not die;
	get_disks($source, $param->{source_user}) if $source->{vmid};

	update_cron($job);
	update_state($job);
    }); #cron and state lock

    return if $param->{skip};

    eval { sync($param) };
    if (my $err = $@) {
	destroy_job($param);
	print $err;
    }
}

sub get_job {
    my ($param) = @_;

    my $cfg = read_cron();

    if (!$cfg->{$param->{source}}->{$param->{name}}) {
	die "Job  with source $param->{source} and name $param->{name} does not exist\n" ;
    }
    my $job = $cfg->{$param->{source}}->{$param->{name}};
    $job->{name} = $param->{name};
    $job->{source} = $param->{source};
    $job = add_state_to_job($job);

    return $job;
}

sub destroy_job {
    my ($param) = @_;

    locked("$CONFIG_PATH/cron_and_state.lock", sub {
	my $job = get_job($param);
	$job->{state} = "del";

	update_cron($job);
	update_state($job);
    });
}

sub get_instance_id {
    my ($pid) = @_;

    my $stat = read_file("/proc/$pid/stat", 1)
	or die "unable to read process stats\n";
    my $boot_id = read_file("/proc/sys/kernel/random/boot_id", 1)
	or die "unable to read boot ID\n";

    my $stats = [ split(/\s+/, $stat) ];
    my $starttime = $stats->[21];
    chomp($boot_id);

    return "${pid}:${starttime}:${boot_id}";
}

sub instance_exists {
    my ($instance_id) = @_;

    if (defined($instance_id) && $instance_id =~ m/^([1-9][0-9]*):/) {
	my $pid = $1;
	my $actual_id = eval { get_instance_id($pid); };
	return defined($actual_id) && $actual_id eq $instance_id;
    }

    return 0;
}

sub sync {
    my ($param) = @_;

    my $job;

    locked("$CONFIG_PATH/cron_and_state.lock", sub {
	eval { $job = get_job($param) };

	if ($job) {
	    my $state = $job->{state} // 'ok';
	    $state = 'ok' if !instance_exists($job->{instance_id});

	    if ($state eq "syncing" || $state eq "waiting") {
		die "Job --source $param->{source} --name $param->{name} is already scheduled to sync\n";
	    }

	    $job->{state} = "waiting";
	    $job->{instance_id} = $INSTANCE_ID;

	    update_state($job);
	}
    });

    locked("$CONFIG_PATH/sync.lock", sub {

	my $date = get_date();

	my $dest;
	my $source;
	my $vm_type;

	locked("$CONFIG_PATH/cron_and_state.lock", sub {
	    #job might've changed while we waited for the sync lock, but we can be sure it's not syncing
	    eval { $job = get_job($param); };

	    if ($job && defined($job->{state}) && $job->{state} eq "stopped") {
		die "Job --source $param->{source} --name $param->{name} has been disabled\n";
	    }

	    $dest = parse_target($param->{dest});
	    $source = parse_target($param->{source});

	    $vm_type = vm_exists($source, $param->{source_user});
	    $source->{vm_type} = $vm_type;

	    if ($job) {
		$job->{state} = "syncing";
		$job->{vm_type} = $vm_type if !$job->{vm_type};
		update_state($job);
	    }
	}); #cron and state lock

	my $sync_path = sub {
	    my ($source, $dest, $job, $param, $date) = @_;

	    ($dest->{old_snap}, $dest->{last_snap}) = snapshot_get($source, $dest, $param->{maxsnap}, $param->{name}, $param->{dest_user});

	    prepare_prepended_target($source, $dest, $param->{dest_user}) if defined($dest->{prepend});

	    snapshot_add($source, $dest, $param->{name}, $date, $param->{source_user}, $param->{dest_user});

	    send_image($source, $dest, $param);

	    snapshot_destroy($source, $dest, $param->{method}, $dest->{old_snap}, $param->{source_user}, $param->{dest_user}) if ($source->{destroy} && $dest->{old_snap});

	};

	eval{
	    if ($source->{vmid}) {
		die "VM $source->{vmid} doesn't exist\n" if !$vm_type;
		die "source-user has to be root for syncing VMs\n" if ($param->{source_user} ne "root");
		my $disks = get_disks($source, $param->{source_user});

		foreach my $disk (sort keys %{$disks}) {
		    $source->{all} = $disks->{$disk}->{all};
		    $source->{pool} = $disks->{$disk}->{pool};
		    $source->{path} = $disks->{$disk}->{path} if $disks->{$disk}->{path};
		    $source->{last_part} = $disks->{$disk}->{last_part};

		    $dest->{prepend} = $disks->{$disk}->{storage_id}
			if $param->{prepend_storage_id};

		    &$sync_path($source, $dest, $job, $param, $date);
		}
		if ($param->{method} eq "ssh" && ($source->{ip} || $dest->{ip})) {
		    send_config($source, $dest,'ssh', $param->{source_user}, $param->{dest_user}, $param->{dest_config_path});
		} else {
		    send_config($source, $dest,'local', $param->{source_user}, $param->{dest_user}, $param->{dest_config_path});
		}
	    } else {
		&$sync_path($source, $dest, $job, $param, $date);
	    }
	};
	if (my $err = $@) {
	    locked("$CONFIG_PATH/cron_and_state.lock", sub {
		eval { $job = get_job($param); };
		if ($job) {
		    $job->{state} = "error";
		    delete $job->{instance_id};
		    update_state($job);
		}
	    });
	    print "Job --source $param->{source} --name $param->{name} got an ERROR!!!\nERROR Message:\n";
	    die "$err\n";
	}

	locked("$CONFIG_PATH/cron_and_state.lock", sub {
	    eval { $job = get_job($param); };
	    if ($job) {
		if (defined($job->{state}) && $job->{state} eq "stopped") {
		    $job->{state} = "stopped";
		} else {
		    $job->{state} = "ok";
		}
		$job->{lsync} = $date;
		delete $job->{instance_id};
		update_state($job);
	    }
	});
    }); #sync lock
}

sub snapshot_get{
    my ($source, $dest, $max_snap, $name, $dest_user) = @_;

    my $cmd = [];
    push @$cmd, 'ssh', "$dest_user\@$dest->{ip}", '--', if $dest->{ip};
    push @$cmd, 'zfs', 'list', '-r', '-t', 'snapshot', '-Ho', 'name', '-S', 'creation';

    my $path = target_dataset($source, $dest);
    push @$cmd, $path;

    my $raw;
    eval {$raw = run_cmd($cmd)};
    if (my $erro =$@) { #this means the volume doesn't exist on dest yet
       return undef;
    }

    my $index = 0;
    my $line = "";
    my $last_snap = undef;
    my $old_snap;

    while ($raw && $raw =~ s/^(.*?)(\n|$)//) {
	$line = $1;
	if ($line =~ m/@(.*)$/) {
	    $last_snap = $1 if (!$last_snap);
	}
	if ($line =~ m/(rep_\Q${name}\E_\d{4}-\d{2}-\d{2}_\d{2}:\d{2}:\d{2})$/) {
	    $old_snap = $1;
	    $index++;
	    if ($index == $max_snap) {
		$source->{destroy} = 1;
		last;
	    };
	}
    }

    return ($old_snap, $last_snap) if $last_snap;

    return undef;
}

sub snapshot_add {
    my ($source, $dest, $name, $date, $source_user, $dest_user) = @_;

    my $snap_name = "rep_$name\_".$date;

    $source->{new_snap} = $snap_name;

    my $path = "$source->{all}\@$snap_name";

    my $cmd = [];
    push @$cmd, 'ssh', "$source_user\@$source->{ip}", '--', if $source->{ip};
    push @$cmd, 'zfs', 'snapshot', $path;
    eval{
	run_cmd($cmd);
    };

    if (my $err = $@) {
	snapshot_destroy($source, $dest, 'ssh', $snap_name, $source_user, $dest_user);
	die "$err\n";
    }
}

sub get_disks {
    my ($target, $user) = @_;

    my $cmd = [];
    push @$cmd, 'ssh', "$user\@$target->{ip}", '--', if $target->{ip};

    if ($target->{vm_type} eq 'qemu') {
	push @$cmd, 'qm', 'config', $target->{vmid};
    } elsif ($target->{vm_type} eq 'lxc') {
	push @$cmd, 'pct', 'config', $target->{vmid};
    } else {
	die "VM Type unknown\n";
    }

    my $res = run_cmd($cmd);

    my $disks = parse_disks($res, $target->{ip}, $target->{vm_type}, $user);

    return $disks;
}

sub run_cmd {
    my ($cmd) = @_;
    print "Start CMD\n" if $DEBUG;
    print Dumper $cmd if $DEBUG;
    if (ref($cmd) eq 'ARRAY') {
	$cmd = join(' ', map { ref($_) ? $$_ : shell_quote($_) } @$cmd);
    }
    my $output = `$cmd 2>&1`;

    die "COMMAND:\n\t$cmd\nGET ERROR:\n\t$output" if 0 != $?;

    chomp($output);
    print Dumper $output if $DEBUG;
    print "END CMD\n" if $DEBUG;
    return $output;
}

sub parse_disks {
    my ($text, $ip, $vm_type, $user) = @_;

    my $disks;

    my $num = 0;
    while ($text && $text =~ s/^(.*?)(\n|$)//) {
	my $line = $1;

	next if $line =~ /media=cdrom/;
	next if $line !~ m/$DISK_KEY_RE/;

	#QEMU if backup is not set include in  sync
	next if $vm_type eq 'qemu' && ($line =~ m/backup=(?i:0|no|off|false)/);

	#LXC if backup is not set do no in sync
	next if $vm_type eq 'lxc' && ($line =~ m/^mp\d:/) && ($line !~ m/backup=(?i:1|yes|on|true)/);

	my $disk = undef;
	my $stor = undef;
	if($line =~ m/$DISK_KEY_RE(.*)$/) {
	    my @parameter = split(/,/,$1);

	    foreach my $opt (@parameter) {
		if ($opt =~ m/^(?:file=|volume=)?([^:]+):([A-Za-z0-9\-]+)$/){
		    $disk = $2;
		    $stor = $1;
		    last;
		}
	    }
	}
	if (!defined($disk) || !defined($stor)) {
	    print "Disk: \"$line\" has no valid zfs dataset format and will be skipped\n";
	    next;
	}

	my $cmd = [];
	push @$cmd, 'ssh', "$user\@$ip", '--' if $ip;
	push @$cmd, 'pvesm', 'path', "$stor:$disk";
	my $path = run_cmd($cmd);

	die "Get no path from pvesm path $stor:$disk\n" if !$path;

	$disks->{$num}->{storage_id} = $stor;

	if ($vm_type eq 'qemu' && $path =~ m/^\/dev\/zvol\/(\w+.*)(\/$disk)$/) {

	    my @array = split('/', $1);
	    $disks->{$num}->{pool} = shift(@array);
	    $disks->{$num}->{all} = $disks->{$num}->{pool};
	    if (0 < @array) {
		$disks->{$num}->{path} = join('/', @array);
		$disks->{$num}->{all} .= "\/$disks->{$num}->{path}";
	    }
	    $disks->{$num}->{last_part} = $disk;
	    $disks->{$num}->{all} .= "\/$disk";

	    $num++;
	} elsif ($vm_type eq 'lxc' && $path =~ m/^\/(\w+.+)(\/(\w+.*))*(\/$disk)$/) {

	    $disks->{$num}->{pool} = $1;
	    $disks->{$num}->{all} = $disks->{$num}->{pool};

	    if ($2) {
		$disks->{$num}->{path} = $3;
		$disks->{$num}->{all} .= "\/$disks->{$num}->{path}";
	    }

	    $disks->{$num}->{last_part} = $disk;
	    $disks->{$num}->{all} .= "\/$disk";

	    $num++;

	} else {
	    die "ERROR: in path\n";
	}
    }

    die "Vm include no disk on zfs.\n" if !$disks->{0};
    return $disks;
}

# how the corresponding dataset is named on the target
sub target_dataset {
    my ($source, $dest) = @_;

    my $target = "$dest->{all}";
    $target .= "/$dest->{prepend}" if defined($dest->{prepend});
    $target .= "/$source->{last_part}" if $source->{last_part};
    $target =~ s!/+!/!g;

    return $target;
}

# create the parent dataset for the actual target
sub prepare_prepended_target {
    my ($source, $dest, $dest_user) = @_;

    die "internal error - not a prepended target\n" if !defined($dest->{prepend});

    # The parent dataset shouldn't be the actual target.
    die "internal error - no last_part for source\n" if !$source->{last_part};

    my $target = "$dest->{all}/$dest->{prepend}";
    $target =~ s!/+!/!g;

    return if check_dataset_exists($target, $dest->{ip}, $dest_user);

    create_file_system($target, $dest->{ip}, $dest_user);
}

sub snapshot_destroy {
    my ($source, $dest, $method, $snap, $source_user, $dest_user) = @_;

    my @zfscmd = ('zfs', 'destroy');
    my $snapshot = "$source->{all}\@$snap";

    eval {
	if($source->{ip} && $method eq 'ssh'){
	    run_cmd(['ssh', "$source_user\@$source->{ip}", '--', @zfscmd, $snapshot]);
	} else {
	    run_cmd([@zfscmd, $snapshot]);
	}
    };
    if (my $erro = $@) {
	warn "WARN: $erro";
    }
    if ($dest) {
	my @ssh = $dest->{ip} ? ('ssh', "$dest_user\@$dest->{ip}", '--') : ();

	my $path = target_dataset($source, $dest);

	eval {
	    run_cmd([@ssh, @zfscmd, "$path\@$snap"]);
	};
	if (my $erro = $@) {
	    warn "WARN: $erro";
	}
    }
}

# check if snapshot for incremental sync exist on source side
sub snapshot_exist {
    my ($source , $dest, $method, $source_user) = @_;

    my $cmd = [];
    push @$cmd, 'ssh', "$source_user\@$source->{ip}", '--' if $source->{ip};
    push @$cmd, 'zfs', 'list', '-rt', 'snapshot', '-Ho', 'name';

    my $path = $source->{all};
    $path .= "\@$dest->{last_snap}";

    push @$cmd, $path;

    eval {run_cmd($cmd)};
    if (my $erro =$@) {
	warn "WARN: $erro";
	return undef;
    }
    return 1;
}

sub send_image {
    my ($source, $dest, $param) = @_;

    my $cmd = [];

    push @$cmd, 'ssh', '-o', 'BatchMode=yes', "$param->{source_user}\@$source->{ip}", '--' if $source->{ip};
    push @$cmd, 'zfs', 'send';
    push @$cmd, '-p', if $param->{properties};
    push @$cmd, '-v' if $param->{verbose};

    if($dest->{last_snap} && snapshot_exist($source , $dest, $param->{method}, $param->{source_user})) {
	push @$cmd, '-i', "$source->{all}\@$dest->{last_snap}";
    }
    push @$cmd, '--', "$source->{all}\@$source->{new_snap}";

    if ($param->{limit}){
	my $bwl = $param->{limit}*1024;
	push @$cmd, \'|', 'cstream', '-t', $bwl;
    }
    my $target = target_dataset($source, $dest);

    push @$cmd, \'|';
    push @$cmd, 'ssh', '-o', 'BatchMode=yes', "$param->{dest_user}\@$dest->{ip}", '--' if $dest->{ip};
    push @$cmd, 'zfs', 'recv', '-F', '--';
    push @$cmd, "$target";

    eval {
	run_cmd($cmd)
    };

    if (my $erro = $@) {
	snapshot_destroy($source, undef, $param->{method}, $source->{new_snap}, $param->{source_user}, $param->{dest_user});
	die $erro;
    };
}


sub send_config{
    my ($source, $dest, $method, $source_user, $dest_user, $dest_config_path) = @_;

    my $source_target = $source->{vm_type} eq 'qemu' ? "$QEMU_CONF/$source->{vmid}.conf": "$LXC_CONF/$source->{vmid}.conf";
    my $dest_target_new ="$source->{vmid}.conf.$source->{vm_type}.$source->{new_snap}";

    my $config_dir = $dest_config_path // $CONFIG_PATH;
    $config_dir .= "/$dest->{last_part}" if $dest->{last_part};

    $dest_target_new = $config_dir.'/'.$dest_target_new;

    if ($method eq 'ssh'){
	if ($dest->{ip} && $source->{ip}) {
	    run_cmd(['ssh', "$dest_user\@$dest->{ip}", '--', 'mkdir', '-p', '--', $config_dir]);
	    run_cmd(['scp', '--', "$source_user\@[$source->{ip}]:$source_target", "$dest_user\@[$dest->{ip}]:$dest_target_new"]);
	} elsif ($dest->{ip}) {
	    run_cmd(['ssh', "$dest_user\@$dest->{ip}", '--', 'mkdir', '-p', '--', $config_dir]);
	    run_cmd(['scp', '--', $source_target, "$dest_user\@[$dest->{ip}]:$dest_target_new"]);
	} elsif ($source->{ip}) {
	    run_cmd(['mkdir', '-p', '--', $config_dir]);
	    run_cmd(['scp', '--', "$source_user\@[$source->{ip}]:$source_target", $dest_target_new]);
	}

	if ($source->{destroy}){
	    my $dest_target_old ="${config_dir}/$source->{vmid}.conf.$source->{vm_type}.$dest->{old_snap}";
	    if($dest->{ip}){
		run_cmd(['ssh', "$dest_user\@$dest->{ip}", '--', 'rm', '-f', '--', $dest_target_old]);
	    } else {
		run_cmd(['rm', '-f', '--', $dest_target_old]);
	    }
	}
    } elsif ($method eq 'local') {
	run_cmd(['mkdir', '-p', '--', $config_dir]);
	run_cmd(['cp', $source_target, $dest_target_new]);
    }
}

sub get_date {
    my ($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) = localtime(time);
    my $datestamp = sprintf ("%04d-%02d-%02d_%02d:%02d:%02d", $year+1900, $mon+1, $mday, $hour, $min, $sec);

    return $datestamp;
}

sub status {
    my $cfg = read_cron();

    my $status_list = sprintf("%-25s%-25s%-10s\n", "SOURCE", "NAME", "STATUS");

    my $states = read_state();

    foreach my $source (sort keys%{$cfg}) {
	foreach my $sync_name (sort keys%{$cfg->{$source}}) {
	    $status_list .= sprintf("%-25s", cut_target_width($source, 25));
	    $status_list .= sprintf("%-25s", cut_target_width($sync_name, 25));
	    $status_list .= "$states->{$source}->{$sync_name}->{state}\n";
	}
    }

    return $status_list;
}

sub enable_job {
    my ($param) = @_;

    locked("$CONFIG_PATH/cron_and_state.lock", sub {
	my $job = get_job($param);
	$job->{state} = "ok";
	update_state($job);
	update_cron($job);
    });
}

sub disable_job {
    my ($param) = @_;

    locked("$CONFIG_PATH/cron_and_state.lock", sub {
	my $job = get_job($param);
	$job->{state} = "stopped";
	update_state($job);
	update_cron($job);
    });
}

my $cmd_help = {
    destroy => qq{
$PROGNAME destroy -source <string> [OPTIONS]

        remove a sync Job from the scheduler

        -name      string

		name of the sync job, if not set it is default

        -source    string

                the source can be an  <VMID> or [IP:]<ZFSPool>[/Path]
    },
    create => qq{
$PROGNAME create -dest <string> -source <string> [OPTIONS]

        Create a sync Job

        -dest      string

		the destination target is like [IP]:<Pool>[/Path]

        -dest-user string

		name of the user on the destination target, root by default

        -limit     integer

		max sync speed in kBytes/s, default unlimited

        -maxsnap   integer

		how much snapshots will be kept before get erased, default 1

        -name      string

		name of the sync job, if not set it is default

        -prepend-storage-id

		If specified, prepend the storage ID to the destination's path(s).

        -skip

		If specified, skip the first sync.

        -source    string

		the source can be an <VMID> or [IP:]<ZFSPool>[/Path]

        -source-user    string

		name of the user on the source target, root by default

	-properties

		If specified, include the dataset's properties in the stream.

	-dest-config-path    string

		specify a custom config path on the destination target. default is /var/lib/pve-zsync
    },
    sync => qq{
$PROGNAME sync -dest <string> -source <string> [OPTIONS]\n

	will sync one time

        -dest      string

		the destination target is like [IP:]<Pool>[/Path]

        -dest-user string

		name of the user on the destination target, root by default

	-limit     integer

		max sync speed in kBytes/s, default unlimited

        -maxsnap   integer

		how much snapshots will be kept before get erased, default 1

        -name      string

		name of the sync job, if not set it is default.
		It is only necessary if scheduler allready contains this source.

        -prepend-storage-id

		If specified, prepend the storage ID to the destination's path(s).

        -source    string

		the source can be an <VMID> or [IP:]<ZFSPool>[/Path]

        -source-user    string

		name of the user on the source target, root by default

	-verbose

		If specified, print out the sync progress.

	-properties

		If specified, include the dataset's properties in the stream.

	-dest-config-path    string

		specify a custom config path on the destination target. default is /var/lib/pve-zsync
    },
    list => qq{
$PROGNAME list

	Get a List of all scheduled Sync Jobs
    },
    status => qq{
$PROGNAME status

	Get the status of all scheduled Sync Jobs
    },
    help => qq{
$PROGNAME help <cmd> [OPTIONS]

	Get help about specified command.

        <cmd>      string

		Command name

	-verbose

		Verbose output format.
    },
    enable => qq{
$PROGNAME enable -source <string> [OPTIONS]

        enable a syncjob and reset error

        -name      string

		name of the sync job, if not set it is default

        -source    string

                the source can be an  <VMID> or [IP:]<ZFSPool>[/Path]
    },
    disable => qq{
$PROGNAME disable -source <string> [OPTIONS]

        pause a sync job

        -name      string

		name of the sync job, if not set it is default

        -source    string

                the source can be an  <VMID> or [IP:]<ZFSPool>[/Path] 
    },
    printpod => 'internal command',

};

if (!$command) {
    usage(); die "\n";
} elsif (!$cmd_help->{$command}) {
    print "ERROR: unknown command '$command'";
    usage(1); die "\n";
}

my @arg = @ARGV;
my $param = parse_argv(@arg);

sub check_params {
    for (@_) {
	die "$cmd_help->{$command}\n" if !$param->{$_};
    }
}

if ($command eq 'destroy') {
    check_params(qw(source));

    check_target($param->{source});
    destroy_job($param);

} elsif ($command eq 'sync') {
    check_params(qw(source dest));

    check_target($param->{source});
    check_target($param->{dest});
    sync($param);

} elsif ($command eq 'create') {
    check_params(qw(source dest));

    check_target($param->{source});
    check_target($param->{dest});
    init($param);

} elsif ($command eq 'status') {
    print status();

} elsif ($command eq 'list') {
    print list();

} elsif ($command eq 'help') {
    my $help_command = $ARGV[1];

    if ($help_command && $cmd_help->{$help_command}) {
	die "$cmd_help->{$help_command}\n";

    }
    if ($param->{verbose}) {
	exec("man $PROGNAME");

    } else {
	usage(1);

    }

} elsif ($command eq 'enable') {
    check_params(qw(source));

    check_target($param->{source});
    enable_job($param);

} elsif ($command eq 'disable') {
    check_params(qw(source));

    check_target($param->{source});
    disable_job($param);

} elsif ($command eq 'printpod') {
    print_pod();
}

sub usage {
    my ($help) = @_;

    print("ERROR:\tno command specified\n") if !$help;
    print("USAGE:\t$PROGNAME <COMMAND> [ARGS] [OPTIONS]\n");
    print("\t$PROGNAME help [<cmd>] [OPTIONS]\n\n");
    print("\t$PROGNAME create -dest <string> -source <string> [OPTIONS]\n");
    print("\t$PROGNAME destroy -source <string> [OPTIONS]\n");
    print("\t$PROGNAME disable -source <string> [OPTIONS]\n");
    print("\t$PROGNAME enable -source <string> [OPTIONS]\n");
    print("\t$PROGNAME list\n");
    print("\t$PROGNAME status\n");
    print("\t$PROGNAME sync -dest <string> -source <string> [OPTIONS]\n");
}

sub check_target {
    my ($target) = @_;
    parse_target($target);
}

sub print_pod {

    my $synopsis = join("\n", sort values %$cmd_help);

    print <<EOF;
=head1 NAME

pve-zsync - PVE ZFS Replication Manager

=head1 SYNOPSIS

pve-zsync <COMMAND> [ARGS] [OPTIONS]

$synopsis

=head1 DESCRIPTION

This Tool helps you to sync your VM or directory which stored on ZFS between 2 servers.
This tool also has the capability to add jobs to cron so the sync will be automatically done.
The default syncing interval is set to 15 min, if you want to change this value you can do this in /etc/cron.d/pve-zsync.
To config cron see man crontab.

=head2 PVE ZFS Storage sync Tool

This Tool can get remote pool on other PVE or send Pool to others ZFS machines

=head1 EXAMPLES

add sync job from local VM to remote ZFS Server
pve-zsync create -source=100 -dest=192.168.1.2:zfspool

=head1 IMPORTANT FILES

Cron jobs and config are stored at                      /etc/cron.d/pve-zsync

The VM config get copied on the destination machine to  /var/lib/pve-zsync/

=head1 COPYRIGHT AND DISCLAIMER

Copyright (C) 2007-2021 Proxmox Server Solutions GmbH

This program is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public
License along with this program.  If not, see
<http://www.gnu.org/licenses/>.

EOF
}