package App::Netdisco::Util::Device;

use Dancer qw/:syntax :script/;
use Dancer::Plugin::DBIC 'schema';
use App::Netdisco::Util::Permission qw/check_acl_no check_acl_only/;

use File::Spec::Functions qw(catdir catfile);
use File::Path 'make_path';

use base 'Exporter';
our @EXPORT = ();
our @EXPORT_OK = qw/
  get_device
  delete_device
  renumber_device
  match_to_setting
  is_discoverable is_discoverable_now
  is_arpnipable   is_arpnipable_now
  is_macsuckable  is_macsuckable_now
/;
our %EXPORT_TAGS = (all => \@EXPORT_OK);

=head1 NAME

App::Netdisco::Util::Device

=head1 DESCRIPTION

A set of helper subroutines to support parts of the Netdisco application.

There are no default exports, however the C<:all> tag will export all
subroutines.

=head1 EXPORT_OK

=head2 get_device( $ip )

Given an IP address, returns a L<DBIx::Class::Row> object for the Device in
the Netdisco database. The IP can be for any interface on the device.

If for any reason C<$ip> is already a C<DBIx::Class> Device object, then it is
simply returned.

If the device or interface IP is not known to Netdisco a new Device object is
created for the IP, and returned. This object is in-memory only and not yet
stored to the database.

=cut

sub get_device {
  my $ip = shift;
  return unless $ip;

  # naive check for existing DBIC object
  return $ip if ref $ip;

  # in case the management IP of one device is in use on another device,
  # we first try to get an exact match for the IP as mgmt interface.
  my $alias =
    schema('netdisco')->resultset('DeviceIp')->find($ip, $ip)
    ||
    schema('netdisco')->resultset('DeviceIp')->search({alias => $ip})->first;
  $ip = $alias->ip if defined $alias;

  return schema('netdisco')->resultset('Device')->with_times
    ->find_or_new({ip => $ip});
}

=head2 delete_device( $ip, $archive? )

Given an IP address, deletes the device from Netdisco, including all related
data such as logs and nodes. If the C<$archive> parameter is true, then nodes
will be maintained in an archive state.

Returns true if the transaction completes, else returns false.

=cut

sub delete_device {
  my ($ip, $archive, $log) = @_;
  my $device = get_device($ip) or return 0;
  return 0 if not $device->in_storage;

  my $happy = 0;
  schema('netdisco')->txn_do(sub {
    # will delete everything related too...
    schema('netdisco')->resultset('Device')
      ->search({ ip => $device->ip })->delete({archive_nodes => $archive});

    schema('netdisco')->resultset('UserLog')->create({
      username => session('logged_in_user'),
      userip => scalar eval {request->remote_address},
      event => (sprintf "Delete device %s", $device->ip),
      details => $log,
    });

    $happy = 1;
  });

  return $happy;
}

=head2 renumber_device( $current_ip, $new_ip )

Will update all records in Netdisco referring to the device with
C<$current_ip> to use C<$new_ip> instead, followed by renumbering the
device itself.

Returns true if the transaction completes, else returns false.

=cut

sub renumber_device {
  my ($ip, $new_ip) = @_;
  my $device = get_device($ip) or return 0;
  return 0 if not $device->in_storage;

  my $happy = 0;
  schema('netdisco')->txn_do(sub {
    $device->renumber($new_ip)
      or die "cannot renumber to: $new_ip"; # rollback

    schema('netdisco')->resultset('UserLog')->create({
      username => session('logged_in_user'),
      userip => scalar eval {request->remote_address},
      event => (sprintf "Renumber device %s to %s", $ip, $new_ip),
    });

    $happy = 1;
  });

  return $happy;
}

=head2 match_to_setting( $type, $setting_name )

Given a C<$type> (which may be any text value), returns true if any of the
list of regular expressions in C<$setting_name> is matched, otherwise returns
false.

=cut

sub match_to_setting {
    my ($type, $setting_name) = @_;
    return 0 unless $type and $setting_name;
    return (scalar grep {$type =~ m/$_/}
                        @{setting($setting_name) || []});
}

sub _bail_msg { debug $_[0]; return 0; }

=head2 is_discoverable( $ip, [$device_type, \@device_capabilities]? )

Given an IP address, returns C<true> if Netdisco on this host is permitted by
the local configuration to discover the device.

The configuration items C<discover_no> and C<discover_only> are checked
against the given IP.

If C<$device_type> is also given, then C<discover_no_type> will be checked.
Also respects C<discover_phones> and C<discover_waps> if either are set to
false.

Also checks if the device is a pseudo device and no offline cache exists.

Returns false if the host is not permitted to discover the target device.

=cut

sub is_discoverable {
  my ($ip, $remote_type, $remote_cap) = @_;
  my $device = get_device($ip) or return 0;
  $remote_type ||= '';
  $remote_cap  ||= [];

  my $pseudo_cache = catfile( catdir(($ENV{NETDISCO_HOME} || $ENV{HOME}), 'logs', 'snapshots'), $device->ip );
  return _bail_msg("is_discoverable: $device is pseudo-device without offline cache")
    if $device->is_pseudo and ! -f $pseudo_cache;

  return _bail_msg("is_discoverable: $device matches wap_platforms but discover_waps is not enabled")
    if ((not setting('discover_waps')) and
        (match_to_setting($remote_type, 'wap_platforms') or
         scalar grep {match_to_setting($_, 'wap_capabilities')} @$remote_cap));

  return _bail_msg("is_discoverable: $device matches phone_platforms but discover_phones is not enabled")
    if ((not setting('discover_phones')) and
        (match_to_setting($remote_type, 'phone_platforms') or
         scalar grep {match_to_setting($_, 'phone_capabilities')} @$remote_cap));

  return _bail_msg("is_discoverable: $device matched discover_no_type")
    if (match_to_setting($remote_type, 'discover_no_type'));

  return _bail_msg("is_discoverable: $device matched discover_no")
    if check_acl_no($device, 'discover_no');

  return _bail_msg("is_discoverable: $device failed to match discover_only")
    unless check_acl_only($device, 'discover_only');

  return 1;
}

=head2 is_discoverable_now( $ip, $device_type? )

Same as C<is_discoverable>, but also compares the C<last_discover> field
of the C<device> to the C<discover_min_age> configuration.

Returns false if the host is not permitted to discover the target device.

=cut

sub is_discoverable_now {
  my ($ip, $remote_type) = @_;
  my $device = get_device($ip) or return 0;

  if ($device->in_storage
      and $device->since_last_discover and setting('discover_min_age')
      and $device->since_last_discover < setting('discover_min_age')) {

      return _bail_msg("is_discoverable: $device last discover < discover_min_age");
  }

  return is_discoverable(@_);
}

=head2 is_arpnipable( $ip )

Given an IP address, returns C<true> if Netdisco on this host is permitted by
the local configuration to arpnip the device.

The configuration items C<arpnip_no> and C<arpnip_only> are checked
against the given IP.

Also checks if the device reports layer 3 capability.

Returns false if the host is not permitted to arpnip the target device.

=cut

sub is_arpnipable {
  my $ip = shift;
  my $device = get_device($ip) or return 0;

  return _bail_msg("is_arpnipable: $device has no layer 3 capability")
    if ($device->in_storage() and not $device->has_layer(3));

  return _bail_msg("is_arpnipable: $device matched arpnip_no")
    if check_acl_no($device, 'arpnip_no');

  return _bail_msg("is_arpnipable: $device failed to match arpnip_only")
    unless check_acl_only($device, 'arpnip_only');

  return 1;
}

=head2 is_arpnipable_now( $ip )

Same as C<is_arpnipable>, but also compares the C<last_arpnip> field
of the C<device> to the C<arpnip_min_age> configuration.

Returns false if the host is not permitted to arpnip the target device.

=cut

sub is_arpnipable_now {
  my ($ip) = @_;
  my $device = get_device($ip) or return 0;

  if ($device->in_storage
      and $device->since_last_arpnip and setting('arpnip_min_age')
      and $device->since_last_arpnip < setting('arpnip_min_age')) {

      return _bail_msg("is_arpnipable: $device last arpnip < arpnip_min_age");
  }

  return is_arpnipable(@_);
}

=head2 is_macsuckable( $ip )

Given an IP address, returns C<true> if Netdisco on this host is permitted by
the local configuration to macsuck the device.

The configuration items C<macsuck_no> and C<macsuck_only> are checked
against the given IP.

Also checks if the device reports layer 2 capability.

Returns false if the host is not permitted to macsuck the target device.

=cut

sub is_macsuckable {
  my $ip = shift;
  my $device = get_device($ip) or return 0;

  return _bail_msg("is_macsuckable: $device has no layer 2 capability")
    if ($device->in_storage() and not $device->has_layer(2));

  return _bail_msg("is_macsuckable: $device matched macsuck_no")
    if check_acl_no($device, 'macsuck_no');

  return _bail_msg("is_macsuckable: $device failed to match macsuck_only")
    unless check_acl_only($device, 'macsuck_only');

  return 1;
}

=head2 is_macsuckable_now( $ip )

Same as C<is_macsuckable>, but also compares the C<last_macsuck> field
of the C<device> to the C<macsuck_min_age> configuration.

Returns false if the host is not permitted to macsuck the target device.

=cut

sub is_macsuckable_now {
  my ($ip) = @_;
  my $device = get_device($ip) or return 0;

  if ($device->in_storage
      and $device->since_last_macsuck and setting('macsuck_min_age')
      and $device->since_last_macsuck < setting('macsuck_min_age')) {

      return _bail_msg("is_macsuckable: $device last macsuck < macsuck_min_age");
  }

  return is_macsuckable(@_);
}

1;