#!/usr/bin/env perl

use strict;
use warnings;

use FindBin;
FindBin::again();
use Path::Class 'dir';

# get a segfault if we load this later
use if $^O eq 'linux', 'Sys::Proctitle';

BEGIN {
  # stuff useful locations into @INC
  unshift @INC,
    dir($FindBin::RealBin)->parent->subdir('lib')->stringify,
    dir($FindBin::RealBin, 'lib')->stringify;

  unshift @INC,
    split m/:/, ($ENV{NETDISCO_INC} || '');
}

use App::Netdisco;
use Dancer qw/:moose :script/;
warning sprintf "App::Netdisco %s backend", ($App::Netdisco::VERSION || 'HEAD');

use App::Netdisco::Util::Daemon;
use NetAddr::IP::Lite ':lower'; # to quench AF_INET6 symbol errors
use Role::Tiny::With;

use MCE::Signal '-setpgrp';
use MCE::Flow Sereal => 1;
use MCE::Queue;

# set temporary MCE files' location in home directory
my $home = ($ENV{NETDISCO_HOME} || $ENV{HOME});
my $tmp_dir = ($ENV{NETDISCO_TEMP} || dir($home, 'tmp'));
mkdir $tmp_dir if ! -d $tmp_dir;

setpgrp(0,0); # only portable variety of setpgrp
prctl 'netdisco-daemon: master';

# shared local job queue
my $Q = MCE::Queue->new;

mce_flow {
  task_name => [qw/ scheduler manager poller /],
  max_workers => [ 1, 1, 'AUTO * 2' ], # FIXME allow setting override
  tmp_dir => $tmp_dir,
  on_post_exit => sub { MCE->restart_worker() },
}, _mk_wkr('Scheduler'), _mk_wkr('Manager'), _mk_wkr('Poller');

sub _mk_wkr {
  my $role = shift;
  return sub {
    my $self = shift;
    my $wid = $self->wid;
    $self->{Q} = $Q; # FIXME make it a method

    prctl sprintf 'netdisco-daemon: worker #%s %s: init', $wid, lc($role);
    info "applying role $role to worker $wid";

    # post-fork, become manager, scheduler, poller, etc
    Role::Tiny->apply_roles_to_object(
      $self => "App::Netdisco::Daemon::Worker::$role");

    $self->worker_begin if $self->can('worker_begin');
    $self->worker_body;
  };
}

#use List::Util 'sum';
#sub num_workers {
#  return sum( 0, map { setting('workers')->{$_} }
#                     values %{setting('job_type_keys')} );
#}

#sub restart_this_worker {
#  my ($self, $e) = @_;
#  reset_jobs($e->{wid});
#
#  debug "restarting worker ". MCE->wid();
#  MCE->restart_worker();
#  $self->restart_worker($e->{wid});
#}

#sub build_tasks_list {
#  # NB MCE does not like max_workers => 0
#  my $tasks = [];
#
#  push @$tasks, {
#    max_workers => 1,
#    user_begin => worker_factory('Manager'),
#  } if num_workers() > 0;
#
#  push @$tasks, {
#    max_workers => 1,
#    user_begin => worker_factory('Scheduler'),
#  } if setting('schedule');
#
#  my @logmsg = ();
#  foreach my $key (keys %{setting('job_type_keys')}) {
#      my $val = setting('job_type_keys')->{$key};
#
#      setting('workers')->{$val} = 2
#        if !defined setting('workers')->{$val};
#
#      push @logmsg, setting('workers')->{$val} ." $key";
#      push @$tasks, {
#        max_workers => setting('workers')->{$val},
#        user_begin => worker_factory($key),
#      } if setting('workers')->{$val};
#  }
#
#  info sprintf "MCE will load: %s Manager, %s Scheduler, %s",
#    (num_workers() ? 1 : 0),
#    (setting('schedule') ? 1 : 0),
#    (join ', ', @logmsg);
#
#  return $tasks;
#}

#sub worker_factory {
#  my $role = shift;
#  return sub {
#    my $self = shift;
#    my $wid = $self->wid;
#    prctl sprintf 'netdisco-daemon: worker #%s %s: init', $wid, lc($role);
#    info "applying role $role to worker $wid";
#
#    # $self->sendto('stderr', ">>> worker $wid starting with role $role\n");
#    Role::Tiny->apply_roles_to_object($self, "App::Netdisco::Daemon::Worker::$role");
#
#    $self->worker_begin if $self->can('worker_begin');
#  };
#}

#my $mce = MCE->new(
#  spawn_delay => 0.15,
#  job_delay   => 1.15,
#  tmp_dir     => $tmp_dir,
#  user_func    => sub { $_[0]->worker_body },
#  on_post_exit => \&restart_this_worker,
#  user_tasks   => build_tasks_list(),
#)->run();

=head1 NAME

netdisco-daemon-fg - Job Control for Netdisco

=head1 SEE ALSO

=over 4

=item *

L<App::Netdisco>

=back

=cut