# 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/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.

package Bugzilla::WebService::Util;

use 5.10.1;
use strict;
use warnings;

use Bugzilla::Logging;
use Bugzilla::Flag;
use Bugzilla::FlagType;
use Bugzilla::Error;
use Bugzilla::WebService::Constants;

use Storable qw(dclone);
use URI::Escape qw(uri_unescape);
use Type::Params qw( compile );
use Types::Standard -all;

use base qw(Exporter);

# We have to "require", not "use" this, because otherwise it tries to
# use features of Test::More during import().
require Test::Taint if ${^TAINT};

our @EXPORT_OK = qw(
  extract_flags
  filter
  filter_wants
  taint_data
  validate
  translate
  params_to_objects
  fix_credentials
);

sub extract_flags {
  my ($flags, $bug, $attachment) = @_;
  my (@new_flags, @old_flags);

  my $flag_types    = $attachment ? $attachment->flag_types : $bug->flag_types;
  my $current_flags = $attachment ? $attachment->flags      : $bug->flags;

  # Copy the user provided $flags as we may call extract_flags more than
  # once when editing multiple bugs or attachments.
  my $flags_copy = dclone($flags);

  foreach my $flag (@$flags_copy) {
    my $id      = $flag->{id};
    my $type_id = $flag->{type_id};

    my $new  = delete $flag->{new};
    my $name = delete $flag->{name};

    if ($id) {
      my $flag_obj = grep($id == $_->id, @$current_flags);
      $flag_obj
        || ThrowUserError('object_does_not_exist',
        {class => 'Bugzilla::Flag', id => $id});
    }
    elsif ($type_id) {
      my $type_obj = grep($type_id == $_->id, @$flag_types);
      $type_obj
        || ThrowUserError('object_does_not_exist',
        {class => 'Bugzilla::FlagType', id => $type_id});
      if (!$new) {
        my @flag_matches = grep($type_id == $_->type->id, @$current_flags);
        @flag_matches > 1 && ThrowUserError('flag_not_unique', {value => $type_id});
        if (!@flag_matches) {
          delete $flag->{id};
        }
        else {
          delete $flag->{type_id};
          $flag->{id} = $flag_matches[0]->id;
        }
      }
    }
    elsif ($name) {
      my @type_matches = grep($name eq $_->name, @$flag_types);
      @type_matches > 1 && ThrowUserError('flag_type_not_unique', {value => $name});
      @type_matches
        || ThrowUserError('object_does_not_exist',
        {class => 'Bugzilla::FlagType', name => $name});
      if ($new) {
        delete $flag->{id};
        $flag->{type_id} = $type_matches[0]->id;
      }
      else {
        my @flag_matches = grep($name eq $_->type->name, @$current_flags);
        @flag_matches > 1 && ThrowUserError('flag_not_unique', {value => $name});
        if (@flag_matches) {
          $flag->{id} = $flag_matches[0]->id;
        }
        else {
          delete $flag->{id};
          $flag->{type_id} = $type_matches[0]->id;
        }
      }
    }

    if ($flag->{id}) {
      push(@old_flags, $flag);
    }
    else {
      push(@new_flags, $flag);
    }
  }

  return (\@old_flags, \@new_flags);
}

sub filter($$;$$) {
  my ($params, $hash, $types, $prefix) = @_;
  my %newhash = %$hash;

  foreach my $key (keys %$hash) {
    delete $newhash{$key} if !filter_wants($params, $key, $types, $prefix);
  }

  return \%newhash;
}

sub filter_wants($$;$$) {
  my ($params, $field, $types, $prefix) = @_;

  # Since this is operation is resource intensive, we will cache the results
  # This assumes that $params->{*_fields} doesn't change between calls
  my $cache = Bugzilla->request_cache->{filter_wants} ||= {};
  $field = "${prefix}.${field}" if $prefix;

  if (exists $cache->{$field}) {
    return $cache->{$field};
  }

  # Mimic old behavior if no types provided
  my %field_types
    = map { $_ => 1 } (ref $types ? @$types : ($types || 'default'));

  my %include = map { $_ => 1 } @{$params->{'include_fields'} || []};
  my %exclude = map { $_ => 1 } @{$params->{'exclude_fields'} || []};

  my %include_types;
  my %exclude_types;

  # Only return default fields if nothing is specified
  $include_types{default} = 1 if !%include;

  # Look for any field types requested
  foreach my $key (keys %include) {
    next if $key !~ /^_(.*)$/;
    $include_types{$1} = 1;
    delete $include{$key};
  }
  foreach my $key (keys %exclude) {
    next if $key !~ /^_(.*)$/;
    $exclude_types{$1} = 1;
    delete $exclude{$key};
  }

  # Explicit inclusion/exclusion
  return $cache->{$field} = 0 if $exclude{$field};
  return $cache->{$field} = 1 if $include{$field};

  # If the user has asked to include all or exclude all
  return $cache->{$field} = 0 if $exclude_types{'all'};
  return $cache->{$field} = 1 if $include_types{'all'};

  # If the user has not asked for any fields specifically or if the user has asked
  # for one or more of the field's types (and not excluded them)
  foreach my $type (keys %field_types) {
    return $cache->{$field} = 0 if $exclude_types{$type};
    return $cache->{$field} = 1 if $include_types{$type};
  }

  my $wants = 0;
  if ($prefix) {

    # Include the field if the parent is include (and this one is not excluded)
    $wants = 1 if $include{$prefix};
  }
  else {
    # We want to include this if one of the sub keys is included
    my $key = $field . '.';
    my $len = length($key);
    $wants = 1 if grep { substr($_, 0, $len) eq $key } keys %include;
  }

  return $cache->{$field} = $wants;
}

sub taint_data {
  my @params = @_;
  return if !@params;

  # Though this is a private function, it hasn't changed since 2004 and
  # should be safe to use, and prevents us from having to write it ourselves
  # or require another module to do it.
  if (${^TAINT}) {
    Test::Taint::_deeply_traverse(\&_delete_bad_keys, \@params);
    Test::Taint::taint_deeply(\@params);
  }
}

sub _delete_bad_keys {
  foreach my $item (@_) {
    next if ref $item ne 'HASH';
    foreach my $key (keys %$item) {

      # Making something a hash key always untaints it, in Perl.
      # However, we need to validate our argument names in some way.
      # We know that all hash keys passed in to the WebService will
      # match \w+, so we delete any key that doesn't match that.
      if ($key !~ /^[\w\.\-]+$/) {
        delete $item->{$key};
      }
    }
  }
  return @_;
}

sub validate {
  my ($self, $params, @keys) = @_;
  my $cache_key = join('|', (caller(1))[3], sort @keys);

  # Type->of() is the same as Type[], used here because it is easier
  # to chain with plus_coercions.
  state $array_of_nonrefs
    = ArrayRef->of(Maybe [Value])->plus_coercions(Maybe [Value], q{ [ $_ ] },);
  state $type_cache = {};
  my $params_type = $type_cache->{$cache_key} //= do {
    my %fields = map { $_ => Optional [$array_of_nonrefs] } @keys;
    Maybe [Dict [%fields, slurpy Any]];
  };

  # If $params is defined but not a reference, then we weren't
  # sent any parameters at all, and we're getting @keys where
  # $params should be.
  return ($self, undef) if (defined $params and !ref $params);

  # If @keys is not empty then we convert any named
  # parameters that have scalar values to arrayrefs
  # that match.
  $params = $params_type->coerce($params);
  if (my $type_error = $params_type->validate($params)) {
    FATAL("validate() found type error: $type_error");
    ThrowUserError('invalid_params', {type_error => $type_error}) if $type_error;
  }

  return ($self, $params);
}

sub translate {
  my ($params, $mapped) = @_;
  my %changes;
  while (my ($key, $value) = each(%$params)) {
    my $new_field = $mapped->{$key} || $key;
    $changes{$new_field} = $value;
  }
  return \%changes;
}

sub params_to_objects {
  my ($params, $class) = @_;
  my (@objects, @objects_by_ids);

  @objects = map { $class->check($_) } @{$params->{names}} if $params->{names};

  @objects_by_ids = map { $class->check({id => $_}) } @{$params->{ids}}
    if $params->{ids};

  push(@objects, @objects_by_ids);
  my %seen;
  @objects = grep { !$seen{$_->id}++ } @objects;
  return \@objects;
}

sub fix_credentials {
  my ($params, $cgi) = @_;

  # Allow user to pass in authentication details in X-Headers
  # This allows callers to keep credentials out of GET request query-strings
  if ($cgi) {
    foreach my $field (keys %{API_AUTH_HEADERS()}) {
      next
        if exists $params->{API_AUTH_HEADERS->{$field}}
        || ($cgi->http($field) // '') eq '';
      $params->{API_AUTH_HEADERS->{$field}} = uri_unescape($cgi->http($field));
    }
  }

  # Allow user to pass in login=foo&password=bar as a convenience
  # even if not calling GET /login. We also do not delete them as
  # GET /login requires "login" and "password".
  if (exists $params->{'login'} && exists $params->{'password'}) {
    $params->{'Bugzilla_login'}    = delete $params->{'login'};
    $params->{'Bugzilla_password'} = delete $params->{'password'};
  }

  # Allow user to pass api_key=12345678 as a convenience which becomes
  # "Bugzilla_api_key" which is what the auth code looks for.
  if (exists $params->{api_key}) {
    $params->{Bugzilla_api_key} = delete $params->{api_key};
  }

  # Allow user to pass token=12345678 as a convenience which becomes
  # "Bugzilla_token" which is what the auth code looks for.
  if (exists $params->{'token'}) {
    $params->{'Bugzilla_token'} = delete $params->{'token'};
  }

  # Allow extensions to modify the credential data before login
  Bugzilla::Hook::process('webservice_fix_credentials', {params => $params});
}

__END__

=head1 NAME

Bugzilla::WebService::Util - Utility functions used inside of the WebService
code. These are B<not> functions that can be called via the WebService.

=head1 DESCRIPTION

This is somewhat like L<Bugzilla::Util>, but these functions are only used
internally in the WebService code.

=head1 SYNOPSIS

 filter({ include_fields => ['id', 'name'],
          exclude_fields => ['name'] }, $hash);
 my $wants = filter_wants $params, 'field_name';
 validate(@_, 'ids');

=head1 METHODS

=head2 filter

This helps implement the C<include_fields> and C<exclude_fields> arguments
of WebService methods. Given a hash (the second argument to this subroutine),
this will remove any keys that are I<not> in C<include_fields> and then remove
any keys that I<are> in C<exclude_fields>.

An optional third option can be passed that prefixes the field name to allow
filtering of data two or more levels deep.

For example, if you want to filter out the C<id> key/value in components returned
by Product.get, you would use the value C<component.id> in your C<exclude_fields>
list.

=head2 filter_wants

Returns C<1> if a filter would preserve the specified field when passing
a hash to L</filter>, C<0> otherwise.

=head2 validate

This helps in the validation of parameters passed into the WebService
methods. Currently it converts listed parameters into an array reference
if the client only passed a single scalar value. It modifies the parameters
hash in place so other parameters should be unaltered.

=head2 params_to_objects

Creates objects of the type passed in as the second parameter, using the
parameters passed to a WebService method (the first parameter to this function).
Helps make life simpler for WebService methods that internally create objects
via both "ids" and "names" fields. Also de-duplicates objects that were loaded
by both "ids" and "names". Returns an arrayref of objects.

=head2 fix_credentials

Allows for certain parameters related to authentication such as Bugzilla_login,
Bugzilla_password, and Bugzilla_token to have shorter named equivalents passed in.
This function converts the shorter versions to their respective internal names.

=head2 extract_flags

Subroutine that takes a list of hashes that are potential flag changes for
both bugs and attachments. Then breaks the list down into two separate lists
based on if the change is to add a new flag or to update an existing flag.

=head1 B<Methods in need of POD>

=over

=item taint_data

=back
