#!/opt/bin/perl

=head1 NAME

   aemp - AnyEvent:MP utility

=head1 SYNOPSIS

   aemp command args...

   # protocol commands
   aemp snd <port> <arg...>      # send a message
   aemp mon <port>               # wait till port is killed
   aemp rpc <port> <arg...>      # send message, append reply
   aemp eval <node> <expr...>    # evaluate expression

   # run a node
   aemp run initialise_args...   # run a node

   # node configuration: protocol endpoints
   aemp setnodeid <nodeid>       # configure the real node id
   aemp delnodeid                # reset node id to default (= inherit)

   # node configuration: secret
   aemp gensecret                # generate a random shared secret
   aemp setsecret <secret>       # set the shared secret
   aemp delsecret                # remove the secret (= inherit)

   # node configuration: TLS
   aemp gencert                  # generate a random certificate
   aemp setcert <file>           # set a certificate (key.pem + certificate.pem)
   aemp delcert                  # remove certificate (= inherit)

   # node configuration: seed addresses for bootstrapping
   aemp setseeds <host:port>,... # set seeds
   aemp delseeds                 # clear all seeds (= inherit)
   aemp addseed <host:port>      # add a seed
   aemp delseed <host:port>      # remove seed

   # node configuration: bind addresses
   aemp setbinds <host:port>,... # set binds
   aemp delbinds                 # clear all binds (= inherit)
   aemp addbind <host:port>      # add a bind address
   aemp delbind <host:port>      # remove a bind address

   # node configuration: services
   aemp setservices initfunc,... # set service functions
   aemp delservices              # clear all services (= inherit)
   aemp addservice <initfunc>    # add an instance of a service
   aemp delservice <initfunc>    # delete one instance of a service

   # profile-specific configuration
   aemp profile <name> <command>... # apply command to profile only
   aemp delprofile <name>        # eradicate the named profile
   aemp showprofile <name>       # display given profile
   aemp showconfig <name>        # display effective config

   # debugging
   aemp trace <nodeid>           # trace the network topology

=head1 DESCRIPTION

With aemp you can configure various aspects of AnyEvent::MP and its
protocol.

You can also start a "default node", a node that only depends on the
static configuration.

=cut

use common::sense;

# should come before anything else, so all modules
# will be loaded on each restart
BEGIN {
   if ($ARGV[0] eq "run") {
      shift;

      # d'oh
      require AnyEvent::Watchdog;
      # now we can load extra modules

      AnyEvent::Watchdog::autorestart (1);
      AnyEvent::Watchdog::heartbeat (300);

      require AnyEvent;
      require AnyEvent::MP;
      AnyEvent::MP::initialise_node (@ARGV);

      AnyEvent::detect () eq "AnyEvent::Impl::EV"
         ? EV::loop ()
         : AE::cv ()->recv;
   }
}

use Carp ();

use JSON::XS;

use AnyEvent;
use AnyEvent::Util;

use AnyEvent::MP;
use AnyEvent::MP::Config;

sub my_run_cmd {
   my ($cmd) = @_;

   my $cv = &run_cmd;
   my $status = $cv->recv;

   $status
      and die "@$cmd: command failed with exit status $status.";
}

sub gen_cert {
   my_run_cmd [qw(openssl req 
                     -new -nodes -x509 -days 3650
                     -newkey rsa:2048 -keyout /dev/fd/3
                     -batch -subj /CN=AnyEvent::MP
              )],
      "<", "/dev/null",
      ">" , \my $cert,
      "3>", \my $key,
      "2>", "/dev/null";

   "$cert$key"
}

our $cfg     = AnyEvent::MP::Config::config;
our $profile = $cfg;

sub trace {
   my ($node) = @_;
   my $cv = AE::cv;
   my %seen;

   my $to = AE::timer 15, 0, sub {
      warn "timeout\n";
      $cv->();
   };

   initialise_node "anon/";

   my $reply = port {
      my ($node, @neigh) = @_;

      @neigh = grep $_ ne $NODE, @neigh;

      print +(join " ", $node, @neigh), "\n";

      for (@neigh) {
         unless ($seen{$_}++) {
            $cv->begin;
            snd $_, up_nodes => $SELF => $_;
         }
      }

      $cv->end;
   };

   $cv->begin;
   snd $reply, seed => $node;

   $cv->recv;
}

sub docmd;

our %CMD = (
   snd => sub {
      my $port = shift @ARGV;
      initialise_node "anon/";

      snd $port, @ARGV; @ARGV = ();

      my $cv = AE::cv;
      my $to = AE::timer 5, 0, sub { $cv->("timeout") };
      mon $port, $cv;
      my $reply = port sub { &$cv };
      snd node_of $port, snd => $reply, "message sent successfully";

      print join " ", $cv->recv, "\n";
   },

   rpc => sub {
      my $port = shift @ARGV;
      initialise_node "anon/";

      my $cv = AE::cv;
      my $to = AE::timer 5, 0, sub { $cv->("timeout") };
      snd $port, @ARGV, port { &$cv }; @ARGV = ();
      mon $port, $cv;

      print join " ", $cv->recv, "\n";
   },

   mon => sub {
      my $port = shift @ARGV;
      initialise_node "anon/";

      mon $port, my $cv = AE::cv;
      print join " ", $cv->recv, "\n";
   },

   eval => sub {
      my $node = node_of shift @ARGV;
      my $expr = join " ", @ARGV; @ARGV = ();
      initialise_node "anon/";

      my $cv = AE::cv;
      my $to = AE::timer 5, 0, sub { $cv->("timeout") };
      AnyEvent::MP::Kernel::eval_on $node, $expr, port { &$cv };
      mon $node, $cv;

      my ($err, @res) = $cv->recv;

      die $err if length $err;

      print +(substr JSON::XS->new->encode (\@res), 1, -1), "\n";
   },

   trace => sub {
      @ARGV >= 1
         or die "node id missing\n";

      trace shift @ARGV;
   },

   setnodeid => sub {
      @ARGV >= 1
         or die "shared secret missing\n";

      $profile->{nodeid} = shift @ARGV;
      ++$cfg->{dirty};
   },
   delnodeid => sub {
      delete $profile->{nodeid};
      ++$cfg->{dirty};
   },

   setsecret => sub {
      @ARGV >= 1
         or die "shared secret missing\n";

      $profile->{secret} = shift @ARGV;
      ++$cfg->{dirty};
   },
   gensecret => sub {
      $profile->{secret} = AnyEvent::MP::Kernel::alnumbits AnyEvent::MP::Kernel::nonce 64;
      ++$cfg->{dirty};
   },
   delsecret => sub {
      delete $profile->{secret};
      ++$cfg->{dirty};
   },

   setcert => sub {
      @ARGV >= 1
         or die "key+certificate pem filename missing\n";

      open my $fh, "<", $ARGV[0]
         or die "$ARGV[0]: $!";

      local $/;
      $profile->{cert} = <$fh>;
      ++$cfg->{dirty};
   },
   gencert => sub {
      $profile->{cert} = gen_cert;
      ++$cfg->{dirty};
   },
   delcert => sub {
      delete $profile->{cert};
      ++$cfg->{dirty};
   },

   setbinds => sub {
      @ARGV >= 1
         or die "bind addresses missing\n";
      $profile->{binds} = [split /,/, shift @ARGV];
      ++$cfg->{dirty};
   },
   delbinds => sub {
      delete $profile->{binds};
      ++$cfg->{dirty};
   },
   addbind => sub {
      @ARGV >= 1
         or die "bind address missing\n";
      my $bind = shift @ARGV;

      @{ $profile->{binds} } = grep $_ ne $bind, @{ $profile->{binds} };
      push @{ $profile->{binds} }, $bind;
      ++$cfg->{dirty};
   },
   delbind => sub {
      @ARGV >= 1
         or die "bind address missing\n";
      my $bind = shift @ARGV;

      @{ $profile->{binds} } = grep $_ ne $bind, @{ $profile->{binds} };
      ++$cfg->{dirty};
   },

   setseeds => sub {
      @ARGV >= 1
         or die "seed addresses missing\n";
      $profile->{seeds} = [split /,/, shift @ARGV];
      ++$cfg->{dirty};
   },
   delseeds => sub {
      delete $profile->{seeds};
      ++$cfg->{dirty};
   },
   addseed => sub {
      @ARGV >= 1
         or die "seed address missing\n";
      my $seed = shift @ARGV;

      @{ $profile->{seeds} } = grep $_ ne $seed, @{ $profile->{seeds} };
      push @{ $profile->{seeds} }, $seed;
      ++$cfg->{dirty};
   },
   delseed => sub {
      @ARGV >= 1
         or die "seed address missing\n";
      my $seed = shift @ARGV;

      @{ $profile->{seeds} } = grep $_ ne $seed, @{ $profile->{seeds} };
      ++$cfg->{dirty};
   },

   setservices => sub {
      @ARGV >= 1
         or die "service specifications missing\n";
      $profile->{services} = [split /,/, shift @ARGV];
      @ARGV = ();
      ++$cfg->{dirty};
   },
   delservices => sub {
      delete $profile->{services};
      ++$cfg->{dirty};
   },
   addservice => sub {
      @ARGV >= 1
         or die "service specification missing\n";
      my $service = shift @ARGV;
      push @{ $profile->{services} }, $service;
      ++$cfg->{dirty};
   },
   delservice => sub {
      @ARGV >= 1
         or die "service specification missing\n";
      my $service = shift @ARGV;
      for (0 .. $#{ $profile->{services} }) {
         next unless $profile->{services}[$_] eq $service;
         splice @{ $profile->{services} }, $_, 1;
         last;
      }
      ++$cfg->{dirty};
   },

   profile => sub {
      @ARGV >= 1
         or die "profile name is missing\n";
      my $name = shift @ARGV;

      $profile = $cfg->{profile}{$name} ||= {};
      ++$cfg->{dirty};
   },
   delprofile => sub {
      @ARGV >= 1
         or die "profile name is missing\n";
      my $name = shift @ARGV;

      delete $cfg->{profile}{$name};
      ++$cfg->{dirty};
   },
   showprofile => sub {
      @ARGV >= 1
         or die "profile name is missing\n";
      my $name = shift @ARGV;

      print JSON::XS->new->pretty->encode ($cfg->{profile}{$name} || {});
   },
   showconfig => sub {
      my $name = @ARGV ? shift @ARGV : AnyEvent::MP::Kernel::_nodename;

      print JSON::XS->new->pretty->encode (AnyEvent::MP::Config::find_profile $name);
   },
);

sub docmd {
   my $cmd = shift @ARGV;

   $CMD{$cmd}
      or die "$cmd: no such aemp command (try man aemp)";

   $CMD{$cmd}();
}

@ARGV
   or die "Usage: aemp subcommand ... (try man aemp)\n";

docmd while @ARGV;