# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

package PBot::Capabilities;
use parent 'PBot::Class';

# purpose: provides interface to set/remove/modify/query user capabilities.
#
# Examples:
#

use warnings; use strict;
use feature 'unicode_strings';

use feature 'switch';
no if $] >= 5.018, warnings => "experimental::smartmatch";

sub initialize {
  my ($self, %conf) = @_;
  my $filename = $conf{filename} // $self->{pbot}->{registry}->get_value('general', 'data_dir') . '/capabilities';
  $self->{caps} = PBot::HashObject->new(name => 'Capabilities', filename => $filename, pbot => $self->{pbot});
  $self->{caps}->load;
  # 'cap' command registered in PBot.pm because $self->{pbot}->{commands} is not yet loaded.

  # add some capabilities used in this file
  $self->add('can-modify-capabilities',  undef, 1);
  $self->add('can-group-capabilities',   undef, 1);
  $self->add('can-ungroup-capabilities', undef, 1);

  # add some useful capabilities
  $self->add('is-whitelisted', undef, 1);
}

sub has {
  my ($self, $cap, $subcap, $depth) = @_;
  my $cap_data = $self->{caps}->get_data($cap);
  return 0 if not defined $cap_data;
  return 1 if $cap eq $subcap and $cap_data->{$subcap};

  $depth //= 10;
  if (--$depth <= 0) {
    $self->{pbot}->{logger}->log("Max recursion reached for PBot::Capabilities->has($cap, $subcap)\n");
    return 0;
  }

  foreach my $c ($self->{caps}->get_keys($cap)) {
    return 1 if $c eq $subcap and $cap_data->{$c};
    return 1 if $self->has($c, $subcap, $depth);
  }
  return 0;
}

sub userhas {
  my ($self, $user, $cap) = @_;
  return 0 if not defined $user;
  return 1 if $user->{$cap};
  foreach my $key (keys %$user) {
    next if $key eq '_name';
    next if not $user->{$key};
    return 1 if $self->has($key, $cap);
  }
  return 0;
}

sub exists {
  my ($self, $cap) = @_;
  $cap = lc $cap;
  foreach my $c ($self->{caps}->get_keys) {
    return 1 if $c eq $cap;
    foreach my $sub_cap ($self->{caps}->get_keys($c)) {
      return 1 if $sub_cap eq $cap;
    }
  }
  return 0;
}

sub add {
  my ($self, $cap, $subcap, $dontsave) = @_;
  if (not defined $subcap) {
    if (not $self->{caps}->exists($cap)) {
      $self->{caps}->add($cap, {}, $dontsave);
    }
  } else {
    if ($self->{caps}->exists($cap)) {
      $self->{caps}->set($cap, $subcap, 1, $dontsave);
    } else {
      $self->{caps}->add($cap, { $subcap => 1 }, $dontsave);
    }
  }
}

sub remove {
  my ($self, $cap, $subcap) = @_;
  $cap = lc $cap;
  if (not defined $subcap) {
    foreach my $c ($self->{caps}->get_keys) {
      foreach my $sub_cap ($self->{caps}->get_keys($c)) {
        $self->{caps}->remove($c, $sub_cap, 1) if $sub_cap eq $cap;
      }
      $self->{caps}->remove($c, undef, 1) if $c eq $cap;
    }
  } else {
    $self->{caps}->remove($cap, $subcap, 1) if $self->{caps}->exists($cap);
  }
  $self->{caps}->save;
}

sub rebuild_botowner_capabilities {
  my ($self) = @_;
  $self->{caps}->remove('botowner', undef, 1);
  foreach my $cap ($self->{caps}->get_keys) {
    $self->add('botowner', $cap, 1);
  }
}

sub list {
  my ($self, $capability) = @_;
  return "No such capability $capability." if defined $capability and not $self->{caps}->exists($capability);

  my @caps;
  my @groups;
  my @standalones;
  my $result;

  if (not defined $capability) {
    @caps = sort $self->{caps}->get_keys;
    $result = 'Capabilities: ';
  } else {
    @caps = sort $self->{caps}->get_keys($capability);
    return "Capability $capability has no grouped capabilities." if not @caps;
    $result = "Grouped capabilities for $capability: ";
  }

  # first list all capabilities that have sub-capabilities (i.e. grouped capabilities)
  # then list stand-alone capabilities
  foreach my $cap (@caps) {
    my $count = $self->{caps}->get_keys($cap);
    if ($count > 0) {
      push @groups, "$cap ($count cap" . ($count == 1 ? '' : 's') . ")" if $count;
    } else {
      push @standalones, $cap;
    }
  }
  $result .= join ', ', @groups, @standalones;
  return $result;
}

sub capcmd {
  my ($self, $from, $nick, $user, $host, $arguments, $stuff) = @_;

  my $command = $self->{pbot}->{interpreter}->shift_arg($stuff->{arglist});
  my $result;
  given ($command) {
    when ('list') {
      my $cap = $self->{pbot}->{interpreter}->shift_arg($stuff->{arglist});
      return $self->list($cap);
    }

    when ('whohas') {
      my $cap = $self->{pbot}->{interpreter}->shift_arg($stuff->{arglist});
      return "Usage: cap whohas <capability>; Lists all users who have <capability>" if not defined $cap;
      return "No such capability $cap." if not $self->exists($cap);
      my $result = "Users with capability $cap: ";
      my $matched = 0;
      my $users = $self->{pbot}->{users}->{users};
      foreach my $channel (sort $users->get_keys) {
        my @matches;
        foreach my $hostmask (sort $users->get_keys($channel)) {
          my $u = $users->get_data($channel, $hostmask);
          push @matches, $u->{name} if $self->userhas($u, $cap);
        }
        if (@matches) {
          $result .= '; ' if $matched;
          my $global = $matched ? 'global: ' : '';
          $result .= $users->get_data($channel, '_name') eq '.*' ? $global : $users->get_data($channel, '_name') . ': ';
          $result .= join ', ', @matches;
          $matched = 1;
        }
      }
      $result .= 'nobody' if not $matched;
      return $result;
    }

    when ('userhas') {
      my ($hostmask, $cap) = $self->{pbot}->{interpreter}->split_args($stuff->{arglist}, 2);
      return "Usage: cap userhas <user> [capability]; Lists capabilities belonging to <user>" if not defined $hostmask;
      $cap = lc $cap if defined $cap;

      my $u = $self->{pbot}->{users}->find_user($from, $hostmask, 1);
      if (not defined $u) {
        $from = 'global' if $from !~ /^#/;
        return "No such user $hostmask in $from."
      }

      if (defined $cap) {
        return "Try again. No such capability $cap." if not $self->exists($cap);
        if ($self->userhas($u, $cap)) {
          return "Yes. User $u->{name} has capability $cap.";
        } else {
          return "No. User $u->{name} does not have capability $cap.";
        }
      } else {
        my $result = "User $u->{name} has capabilities: ";
        my @groups;
        my @single;
        foreach my $key (sort keys %{$u}) {
          next if $key eq '_name';
          next if not $self->exists($key);
          my $count = $self->{caps}->get_keys;
          if ($count > 0) {
            push @groups, "$key ($count cap" . ($count == 1 ? '' : 's') . ")";
          } else {
            push @single, $key;
          }
        }
        if (@groups or @single) {
          $result .= join ', ', @groups, @single;
        } else {
          $result = "User $u->{name} has no capabilities.";
        }
        return $result;
      }
    }

    when ('group') {
      my ($cap, $subcaps) = $self->{pbot}->{interpreter}->split_args($stuff->{arglist}, 2);
      return "Usage: cap group <existing or new capability> <existing capabilities...>" if not defined $cap or not defined $subcaps;

      my $u = $self->{pbot}->{users}->loggedin($from, "$nick!$user\@$host");
      return "You must be logged into your user account to group capabilities together." if not defined $u;
      return "You must have the can-group-capabilities capability to group capabilities together." if not $self->userhas($u, 'can-group-capabilities');

      my @caps = split /\s+|,/, $subcaps;
      foreach my $c (@caps) {
        return "No such capability $c." if not $self->exists($c);
        return "You cannot group a capability with itself." if lc $cap eq lc $c;
        $self->add($cap, $c);
      }
      if (@caps > 1) {
        return "Capabilities " . join(', ', @caps) . " added to the $cap capability group.";
      } else {
        return "Capability $subcaps added to the $cap capability group.";
      }
    }

    when ('ungroup') {
      my ($cap, $subcaps) = $self->{pbot}->{interpreter}->split_args($stuff->{arglist}, 2);
      return "Usage: cap ungroup <existing capability group> <grouped capabilities...>" if not defined $cap or not defined $subcaps;
      return "No such capability $cap." if not $self->exists($cap);

      my $u = $self->{pbot}->{users}->loggedin($from, "$nick!$user\@$host");
      return "You must be logged into your user account to remove capabilities from groups." if not defined $u;
      return "You must have the can-ungroup-capabilities capability to remove capabilities from groups." if not $self->userhas($u, 'can-ungroup-capabilities');

      my @caps = split /\s+|,/, $subcaps;
      foreach my $c (@caps) {
        return "No such capability $c." if not $self->exists($c);
        return "Capability $c does not belong to the $cap capability group." if not $self->has($cap, $c);
        $self->remove($cap, $c);
      }

      if (@caps > 1) {
        return "Capabilities " . join(', ', @caps) . " removed from the $cap capability group.";
      } else {
        return "Capability $subcaps removed from the $cap capability group.";
      }
    }

    default {
      $result = "Usage: cap list [capability] | cap group <existing or new capability group> <existing capabilities...> | cap ungroup <existing capability group> <grouped capabilities...> | cap userhas <user> [capability] | cap whohas <capability>";
    }
  }
  return $result;
}

1;