package PVE::Network::SDN::Controllers::EvpnPlugin;

use strict;
use warnings;

use PVE::INotify;
use PVE::JSONSchema qw(get_standard_option);
use PVE::Tools qw(run_command file_set_contents file_get_contents);
use PVE::RESTEnvironment qw(log_warn);

use PVE::Network::SDN::Controllers::Plugin;
use PVE::Network::SDN::Zones::Plugin;
use Net::IP;

use base('PVE::Network::SDN::Controllers::Plugin');

sub type {
    return 'evpn';
}

sub properties {
    return {
	asn => {
	    type => 'integer',
	    description => "autonomous system number",
	    minimum => 0,
	    maximum => 4294967296
	},
	peers => {
	    description => "peers address list.",
	    type => 'string', format => 'ip-list'
	},
    };
}

sub options {
    return {
	'asn' => { optional => 0 },
	'peers' => { optional => 0 },
    };
}

# Plugin implementation
sub generate_controller_config {
    my ($class, $plugin_config, $controller_cfg, $id, $uplinks, $config) = @_;

    my @peers;
    @peers = PVE::Tools::split_list($plugin_config->{'peers'}) if $plugin_config->{'peers'};

    my $local_node = PVE::INotify::nodename();

    my $asn = $plugin_config->{asn};
    my $ebgp = undef;
    my $loopback = undef;
    my $autortas = undef;
    my $bgprouter = find_bgp_controller($local_node, $controller_cfg);
    my $isisrouter = find_isis_controller($local_node, $controller_cfg);

    if ($bgprouter) {
	$ebgp = 1 if $plugin_config->{'asn'} ne $bgprouter->{asn};
	$loopback = $bgprouter->{loopback} if $bgprouter->{loopback};
	$asn = $bgprouter->{asn} if $bgprouter->{asn};
	$autortas = $plugin_config->{'asn'} if $ebgp;
    } elsif ($isisrouter) {
	$loopback = $isisrouter->{loopback} if $isisrouter->{loopback};
    }

    return if !$asn;

    my $bgp = $config->{frr}->{router}->{"bgp $asn"} //= {};

    my ($ifaceip, $interface) = PVE::Network::SDN::Zones::Plugin::find_local_ip_interface_peers(\@peers, $loopback);
    my $routerid = PVE::Network::SDN::Controllers::Plugin::get_router_id($ifaceip, $interface);

    my $remoteas = $ebgp ? "external" : $asn;

    #global options
    my @controller_config = (
	"bgp router-id $routerid",
	"no bgp hard-administrative-reset",
	"no bgp default ipv4-unicast",
	"coalesce-time 1000",
	"no bgp graceful-restart notification",
    );

    push(@{$bgp->{""}}, @controller_config) if keys %{$bgp} == 0;

    @controller_config = ();

    #VTEP neighbors
    push @controller_config, "neighbor VTEP peer-group";
    push @controller_config, "neighbor VTEP remote-as $remoteas";
    push @controller_config, "neighbor VTEP bfd";

    push @controller_config, "neighbor VTEP ebgp-multihop 10" if $ebgp && $loopback;
    push @controller_config, "neighbor VTEP update-source $loopback" if $loopback;

    # VTEP peers
    foreach my $address (@peers) {
	next if $address eq $ifaceip;
	push @controller_config, "neighbor $address peer-group VTEP";
    }

    push(@{$bgp->{""}}, @controller_config);

    # address-family l2vpn
    @controller_config = ();
    push @controller_config, "neighbor VTEP activate";
    push @controller_config, "neighbor VTEP route-map MAP_VTEP_IN in";
    push @controller_config, "neighbor VTEP route-map MAP_VTEP_OUT out";
    push @controller_config, "advertise-all-vni";
    push @controller_config, "autort as $autortas" if $autortas;
    push(@{$bgp->{"address-family"}->{"l2vpn evpn"}}, @controller_config);

    my $routemap = { rule => undef, action => "permit" };
    push(@{$config->{frr_routemap}->{'MAP_VTEP_IN'}}, $routemap );
    push(@{$config->{frr_routemap}->{'MAP_VTEP_OUT'}}, $routemap );

    return $config;
}

sub generate_controller_zone_config {
    my ($class, $plugin_config, $controller, $controller_cfg, $id, $uplinks, $config) = @_;

    my $local_node = PVE::INotify::nodename();

    my $vrf = "vrf_$id";
    my $vrfvxlan = $plugin_config->{'vrf-vxlan'};
    my $exitnodes = $plugin_config->{'exitnodes'};
    my $exitnodes_primary = $plugin_config->{'exitnodes-primary'};
    my $advertisesubnets = $plugin_config->{'advertise-subnets'};
    my $exitnodes_local_routing = $plugin_config->{'exitnodes-local-routing'};
    my $rt_import;
    $rt_import = [PVE::Tools::split_list($plugin_config->{'rt-import'})] if $plugin_config->{'rt-import'};

    my $asn = $controller->{asn};
    my @peers;
    @peers = PVE::Tools::split_list($controller->{'peers'}) if $controller->{'peers'};
    my $ebgp = undef;
    my $loopback = undef;
    my $autortas = undef;
    my $bgprouter = find_bgp_controller($local_node, $controller_cfg);
    my $isisrouter = find_isis_controller($local_node, $controller_cfg);

    if($bgprouter) {
        $ebgp = 1 if $controller->{'asn'} ne $bgprouter->{asn};
	$loopback = $bgprouter->{loopback} if $bgprouter->{loopback};
	$asn = $bgprouter->{asn} if $bgprouter->{asn};
	$autortas = $controller->{'asn'} if $ebgp;
    } elsif ($isisrouter) {
        $loopback = $isisrouter->{loopback} if $isisrouter->{loopback};
    }

    return if !$vrf || !$vrfvxlan || !$asn;

    my ($ifaceip, $interface) = PVE::Network::SDN::Zones::Plugin::find_local_ip_interface_peers(\@peers, $loopback);
    my $routerid = PVE::Network::SDN::Controllers::Plugin::get_router_id($ifaceip, $interface);

    my $is_gateway = $exitnodes->{$local_node};

    # vrf
    my @controller_config = ();
    push @controller_config, "vni $vrfvxlan";
    #avoid to routes between nodes through the exit nodes
    #null routes subnets of other zones
    if ($is_gateway) {
	my $subnets = PVE::Network::SDN::Vnets::get_subnets();
	my $cidrs = {};
	foreach my $subnetid (sort keys %{$subnets}) {
	    my $subnet = $subnets->{$subnetid};
	    my $cidr = $subnet->{cidr};
	    my $zone = $subnet->{zone};
	    my ($ip, $mask) = split(/\//, $cidr);
	    $cidrs->{$ip} = $mask if $zone ne $id;

	}

	my @sorted_ip =
		map  { $_->[0] }
		sort { $a->[1] <=> $b->[1] }
		map  { [ $_, eval { Net::IP->new( $_ )->intip } ] }
		keys %{$cidrs} if $cidrs;

	foreach my $ip (@sorted_ip) {
	    my $ipversion = Net::IP::ip_is_ipv4($ip) ? 'ip' : 'ipv6';
	    push @controller_config, "$ipversion route $ip/$cidrs->{$ip} null0";
	}
    }

    push(@{$config->{frr}->{vrf}->{"$vrf"}}, @controller_config);

    #main vrf router
    @controller_config = ();
    push @controller_config, "bgp router-id $routerid";
    push @controller_config, "no bgp hard-administrative-reset";
    push @controller_config, "no bgp graceful-restart notification";

#    push @controller_config, "!";
    push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{""}}, @controller_config);

    if ($autortas) {
	push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"l2vpn evpn"}}, "route-target import $autortas:$vrfvxlan");
	push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"l2vpn evpn"}}, "route-target export $autortas:$vrfvxlan");
    }

    if ($is_gateway) {

	$config->{frr_prefix_list}->{'only_default'}->{1} = "permit 0.0.0.0/0";
	$config->{frr_prefix_list_v6}->{'only_default_v6'}->{1} = "permit ::/0";

	if (!$exitnodes_primary || $exitnodes_primary eq $local_node) {
	    #filter default route coming from other exit nodes on primary node or both nodes if no primary is defined.
	    my $routemap_config_v6 = ();
	    push @{$routemap_config_v6}, "match ipv6 address prefix-list only_default_v6";
	    my $routemap_v6 = { rule => $routemap_config_v6, action => "deny" };
	    unshift(@{$config->{frr_routemap}->{'MAP_VTEP_IN'}}, $routemap_v6);

	    my $routemap_config = ();
	    push @{$routemap_config}, "match ip address prefix-list only_default";
	    my $routemap = { rule => $routemap_config, action => "deny" };
	    unshift(@{$config->{frr_routemap}->{'MAP_VTEP_IN'}}, $routemap);

	} elsif ($exitnodes_primary ne $local_node) {
	    my $routemap_config_v6 = ();
	    push @{$routemap_config_v6}, "match ipv6 address prefix-list only_default_v6";
	    push @{$routemap_config_v6}, "set metric 200";
	    my $routemap_v6 = { rule => $routemap_config_v6, action => "permit" };
	    unshift(@{$config->{frr_routemap}->{'MAP_VTEP_OUT'}}, $routemap_v6);

	    my $routemap_config = ();
	    push @{$routemap_config}, "match ip address prefix-list only_default";
	    push @{$routemap_config}, "set metric 200";
	    my $routemap = { rule => $routemap_config, action => "permit" };
	    unshift(@{$config->{frr_routemap}->{'MAP_VTEP_OUT'}}, $routemap);
	}

	if (!$exitnodes_local_routing) {
	    @controller_config = ();
	    #import /32 routes of evpn network from vrf1 to default vrf (for packet return)
	    push @controller_config, "import vrf $vrf";
	    push(@{$config->{frr}->{router}->{"bgp $asn"}->{"address-family"}->{"ipv4 unicast"}}, @controller_config);
	    push(@{$config->{frr}->{router}->{"bgp $asn"}->{"address-family"}->{"ipv6 unicast"}}, @controller_config);

	    @controller_config = ();
	    #redistribute connected to be able to route to local vms on the gateway
	    push @controller_config, "redistribute connected";
	    push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"ipv4 unicast"}}, @controller_config);
	    push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"ipv6 unicast"}}, @controller_config);
	}

	@controller_config = ();
	#add default originate to announce 0.0.0.0/0 type5 route in evpn
	push @controller_config, "default-originate ipv4";
	push @controller_config, "default-originate ipv6";
	push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"l2vpn evpn"}}, @controller_config);
    } elsif ($advertisesubnets) {

	@controller_config = ();
	#redistribute connected networks
	push @controller_config, "redistribute connected";
	push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"ipv4 unicast"}}, @controller_config);
	push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"ipv6 unicast"}}, @controller_config);

	@controller_config = ();
	#advertise connected networks type5 route in evpn
	push @controller_config, "advertise ipv4 unicast";
	push @controller_config, "advertise ipv6 unicast";
	push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"l2vpn evpn"}}, @controller_config);
    }

    if ($rt_import) {
	@controller_config = ();
	foreach my $rt (sort @{$rt_import}) {
	    push @controller_config, "route-target import $rt";
	}
	push(@{$config->{frr}->{router}->{"bgp $asn vrf $vrf"}->{"address-family"}->{"l2vpn evpn"}}, @controller_config);
    }

    return $config;
}

sub generate_controller_vnet_config {
    my ($class, $plugin_config, $controller, $zone, $zoneid, $vnetid, $config) = @_;

    my $exitnodes = $zone->{'exitnodes'};
    my $exitnodes_local_routing = $zone->{'exitnodes-local-routing'};

    return if !$exitnodes_local_routing;

    my $local_node = PVE::INotify::nodename();
    my $is_gateway = $exitnodes->{$local_node};

    return if !$is_gateway;

    my $subnets = PVE::Network::SDN::Vnets::get_subnets($vnetid, 1);
    my @controller_config = ();
    foreach my $subnetid (sort keys %{$subnets}) {
        my $subnet = $subnets->{$subnetid};
	my $cidr = $subnet->{cidr};
	push @controller_config, "ip route $cidr 10.255.255.2 xvrf_$zoneid";
    }
    push(@{$config->{frr_ip_protocol}}, @controller_config);
}

sub on_delete_hook {
    my ($class, $controllerid, $zone_cfg) = @_;

    # verify that zone is associated to this controller
    foreach my $id (keys %{$zone_cfg->{ids}}) {
	my $zone = $zone_cfg->{ids}->{$id};
	die "controller $controllerid is used by $id"
	    if (defined($zone->{controller}) && $zone->{controller} eq $controllerid);
    }
}

sub on_update_hook {
    my ($class, $controllerid, $controller_cfg) = @_;

    # we can only have 1 evpn controller / 1 asn by server

    my $controllernb = 0;
    foreach my $id (keys %{$controller_cfg->{ids}}) {
	next if $id eq $controllerid;
	my $controller = $controller_cfg->{ids}->{$id};
	next if $controller->{type} ne "evpn";
	$controllernb++;
	die "only 1 global evpn controller can be defined" if $controllernb >= 1;
    }
}

sub find_bgp_controller {
    my ($nodename, $controller_cfg) = @_;

    my $res = undef;
    foreach my $id  (keys %{$controller_cfg->{ids}}) {
	my $controller = $controller_cfg->{ids}->{$id};
	next if $controller->{type} ne 'bgp';
	next if $controller->{node} ne $nodename;
	$res = $controller;
	last;
    }
    return $res;
}

sub find_isis_controller {
    my ($nodename, $controller_cfg) = @_;

    my $res = undef;
    foreach my $id  (keys %{$controller_cfg->{ids}}) {
	my $controller = $controller_cfg->{ids}->{$id};
	next if $controller->{type} ne 'isis';
	next if $controller->{node} ne $nodename;
	$res = $controller;
	last;
    }
    return $res;
}

sub generate_frr_recurse{
   my ($final_config, $content, $parentkey, $level) = @_;

   my $keylist = {};
   $keylist->{'address-family'} = 1;
   $keylist->{router} = 1;

   my $exitkeylist = {};
   $exitkeylist->{'address-family'} = 1;

   my $simple_exitkeylist = {};
   $simple_exitkeylist->{router} = 1;

   # FIXME: make this generic
   my $paddinglevel = undef;
   if ($level == 1 || $level == 2) {
	$paddinglevel = $level - 1;
   } elsif ($level == 3 || $level ==  4) {
	$paddinglevel = $level - 2;
   }

   my $padding = "";
   $padding = ' ' x ($paddinglevel) if $paddinglevel;

   if (ref $content eq  'HASH') {
	foreach my $key (sort keys %$content) {
	    next if $key eq 'vrf';
	    if ($parentkey && defined($keylist->{$parentkey})) {
		push @{$final_config}, $padding."!";
		push @{$final_config}, $padding."$parentkey $key";
	    } elsif ($key ne '' && !defined($keylist->{$key})) {
		push @{$final_config}, $padding."$key";
	    }

	    my $option = $content->{$key};
	    generate_frr_recurse($final_config, $option, $key, $level+1);

	    push @{$final_config}, $padding."exit-$parentkey" if $parentkey && defined($exitkeylist->{$parentkey});
	    push @{$final_config}, $padding."exit" if $parentkey && defined($simple_exitkeylist->{$parentkey});
	}
    }

    if (ref $content eq 'ARRAY') {
	push @{$final_config}, map { $padding . "$_" } @$content;
    }
}

sub generate_frr_vrf {
   my ($final_config, $vrfs) = @_;

   return if !$vrfs;

   my @config = ();

   foreach my $id (sort keys %$vrfs) {
	my $vrf = $vrfs->{$id};
	push @config, "!";
	push @config, "vrf $id";
	foreach my $rule (@$vrf) {
	    push @config, " $rule";

	}
	push @config, "exit-vrf";
    }

    push @{$final_config}, @config;
}

sub generate_frr_simple_list {
   my ($final_config, $rules) = @_;

   return if !$rules;

   my @config = ();
   push @{$final_config}, "!";
   foreach my $rule (sort @$rules) {
	push @{$final_config}, $rule;
   }
}

sub generate_frr_interfaces {
   my ($final_config, $interfaces) = @_;

   foreach my $k (sort keys %$interfaces) {
	my $iface = $interfaces->{$k};
	push @{$final_config}, "!";
	push @{$final_config}, "interface $k";
	foreach my $rule (sort @$iface) {
	    push @{$final_config}, " $rule";
	}
   }
}

sub generate_frr_routemap {
   my ($final_config, $routemaps) = @_;

   foreach my $id (sort keys %$routemaps) {

	my $routemap = $routemaps->{$id};
	my $order = 0;
	foreach my $seq (@$routemap) {
		$order++;
		next if !defined($seq->{action});
		my @config = ();
		push @config, "!";
		push @config, "route-map $id $seq->{action} $order";
		my $rule = $seq->{rule};
		push @config, map { " $_" } @$rule;
		push @{$final_config}, @config;
		push @{$final_config}, "exit";
	}
   }
}

sub generate_frr_list {
    my ($final_config, $lists, $type) = @_;

    my $config = [];

    for my $id (sort keys %$lists) {
	my $list = $lists->{$id};

	for my $seq (sort keys %$list) {
	    my $rule = $list->{$seq};
	    push @$config, "$type $id seq $seq $rule";
	}
    }

    if (@$config > 0) {
	push @{$final_config}, "!", @$config;
    }
}

sub read_local_frr_config {
    if (-e "/etc/frr/frr.conf.local") {
	return file_get_contents("/etc/frr/frr.conf.local");
    }
};

sub generate_controller_rawconfig {
    my ($class, $plugin_config, $config) = @_;

    my $nodename = PVE::INotify::nodename();

    my $final_config = [];
    push @{$final_config}, "frr version 8.5.2";
    push @{$final_config}, "frr defaults datacenter";
    push @{$final_config}, "hostname $nodename";
    push @{$final_config}, "log syslog informational";
    push @{$final_config}, "service integrated-vtysh-config";
    push @{$final_config}, "!";

    my $local_conf = read_local_frr_config();
    if ($local_conf) {
	parse_merge_frr_local_config($config, $local_conf);
    }

    generate_frr_vrf($final_config, $config->{frr}->{vrf});
    generate_frr_interfaces($final_config, $config->{frr_interfaces});
    generate_frr_recurse($final_config, $config->{frr}, undef, 0);
    generate_frr_list($final_config, $config->{frr_access_list}, "access-list");
    generate_frr_list($final_config, $config->{frr_prefix_list}, "ip prefix-list");
    generate_frr_list($final_config, $config->{frr_prefix_list_v6}, "ipv6 prefix-list");
    generate_frr_simple_list($final_config, $config->{frr_bgp_community_list});
    generate_frr_routemap($final_config, $config->{frr_routemap});
    generate_frr_simple_list($final_config, $config->{frr_ip_protocol});

    push @{$final_config}, "!";
    push @{$final_config}, "line vty";
    push @{$final_config}, "!";

    my $rawconfig = join("\n", @{$final_config});

    return if !$rawconfig;
    return $rawconfig;
}

sub parse_merge_frr_local_config {
    my ($config, $local_conf) = @_;

    my $section = \$config->{""};
    my $router = undef;
    my $routemap = undef;
    my $routemap_config = ();
    my $routemap_action = undef;

    while ($local_conf =~ /^\s*(.+?)\s*$/gm) {
        my $line = $1;
	$line =~ s/^\s+|\s+$//g;

	if ($line =~ m/^router (.+)$/) {
	    $router = $1;
	    $section = \$config->{'frr'}->{'router'}->{$router}->{""};
	    next;
	} elsif ($line =~ m/^vrf (.+)$/) {
	    $section = \$config->{'frr'}->{'vrf'}->{$1};
	    next;
	} elsif ($line =~ m/^interface (.+)$/) {
	    $section = \$config->{'frr_interfaces'}->{$1};
	    next;
	} elsif ($line =~ m/^bgp community-list (.+)$/) {
	    push(@{$config->{'frr_bgp_community_list'}}, $line);
	    next;
	} elsif ($line =~ m/address-family (.+)$/) {
	    $section = \$config->{'frr'}->{'router'}->{$router}->{'address-family'}->{$1};
	    next;
	} elsif ($line =~ m/^route-map (.+) (permit|deny) (\d+)/) {
	    $routemap = $1;
	    $routemap_config = ();
	    $routemap_action = $2;
	    $section = \$config->{'frr_routemap'}->{$routemap};
	    next;
	} elsif ($line =~ m/^access-list (.+) seq (\d+) (.+)$/) {
	    $config->{'frr_access_list'}->{$1}->{$2} = $3;
	    next;
	} elsif ($line =~ m/^ip prefix-list (.+) seq (\d+) (.*)$/) {
	    $config->{'frr_prefix_list'}->{$1}->{$2} = $3;
	    next;
	} elsif ($line =~ m/^ipv6 prefix-list (.+) seq (\d+) (.*)$/) {
	    $config->{'frr_prefix_list_v6'}->{$1}->{$2} = $3;
	    next;
	} elsif($line =~ m/^exit-address-family$/) {
	    next;
	} elsif($line =~ m/^exit$/) {
	    if($router) {
		$section = \$config->{''};
		$router = undef;
	    } elsif($routemap) {
		push(@{$$section}, { rule => $routemap_config, action => $routemap_action });
		$section = \$config->{''};
		$routemap = undef;
		$routemap_action = undef;
		$routemap_config = ();
	    }
	    next;
	} elsif($line =~ m/!/) {
	    next;
	}

	next if !$section;
	if($routemap) {
	    push(@{$routemap_config}, $line);
	} else {
	    push(@{$$section}, $line);
	}
    }
}

sub write_controller_config {
    my ($class, $plugin_config, $config) = @_;

    my $rawconfig = $class->generate_controller_rawconfig($plugin_config, $config);
    return if !$rawconfig;
    return if !-d "/etc/frr";

    file_set_contents("/etc/frr/frr.conf", $rawconfig);
}

sub reload_controller {
    my ($class) = @_;

    my $conf_file = "/etc/frr/frr.conf";
    my $bin_path = "/usr/lib/frr/frr-reload.py";

    if (!-e $bin_path) {
	log_warn("missing $bin_path. Please install frr-pythontools package");
	return;
    }

    run_command(['systemctl', 'enable', '--now', 'frr'])
	if !-e "/etc/systemd/system/multi-user.target.wants/frr.service";

    my $err = sub {
	my $line = shift;
	if ($line =~ /ERROR:/) {
	    warn "$line \n";
	}
    };

    if (-e $conf_file && -e $bin_path) {
	eval {
	    run_command([$bin_path, '--stdout', '--reload', $conf_file], errfunc => $err);
	};
	if ($@) {
	    warn "frr reload command fail. Restarting frr.";
	    eval { run_command(['systemctl', 'restart', 'frr']); };
	}
    }
}

1;