#!/usr/bin/perl -w

use lib '/opt/zimbra/common/lib/perl5';
use Zimbra::LDAP;
use Zimbra::ZmClient;
use Net::LDAP;
use YAML::Tiny;
use Getopt::Long;
use Data::UUID;
use String::ShellQuote qw(shell_quote);
use Array::Diff;
use List::MoreUtils qw(uniq);
use Hash::Merge::Simple qw(merge);
use Text::Unidecode;
use Email::MIME;
use Email::Sender::Simple qw(sendmail);
use Email::Sender::Transport::Sendmail;
use utf8;
use Data::Dumper;

# This is needed for Email::Sender::Simple
# See https://rt.cpan.org/Public/Bug/Display.html?id=76533
$SIG{CHLD} = sub { wait };

# Init an empty conf
my $conf = {};

# Defaults for command line flags
my $opt = {
  'config=s' => '/opt/zimbra/conf/ldap_sync.yml',
  'dry'      => 0,
  'quiet'    => 0,
  'verbose'  => 0
};

# Read some options from the command line
GetOptions (
  'config=s' => \$opt->{config},
  'dry-run'  => \$opt->{dry},
  'quiet'    => \$opt->{quiet},
  'verbose'  => \$opt->{verbose}
);

if ( $opt->{verbose} and $opt->{quiet} ) {
  print "You cannot use quiet and debug at the same time\n";
  usage();
  exit 255;
}

# Message set in zimbraNotes to identify objects synced from external LDAP
my $sync_from_ldap = "Synced from external LDAP directory. Do not edit this field";

# Check if the config file exists, and if so, parse it
# and load it in $conf
if ( -e $opt->{config} ) {
  log_verbose( "Reading config file " . $opt->{config} );
  my $yaml = YAML::Tiny->read( $opt->{config} )
    or die "Config file " . $opt->{config} . " is invalid\n";

  if ( not $yaml->[0] ) {
    die "Config file " . $opt->{config} . " is invalid\n";
  }

  $conf = $yaml->[0];
} else {
  # If the config file doesn't exist, just die
  die "Config file " . $opt->{config} . " doesn't exist\n";
}

my $zim_ldap = Zimbra::LDAP->new();
my $uuid     = Data::UUID->new();
my $exit     = 0;
my $err      = '';

DOMAIN: foreach my $domain ( keys $conf->{domains} ) {
  log_verbose( "Start to process domain $domain" );

  # Get default config for this domain and merge it with what we have in the config file
  $conf->{domains}->{$domain} = get_default_conf( $conf->{domains}->{$domain} );

  # Search in Zimbra LDAP if the required domain exists
  my $zim_domain_search = $zim_ldap->ldap->search(
    filter => "(&(objectClass=zimbraDomain)(zimbraDomainName=$domain)(!(zimbraDomainAliasTargetId=*)))",
    attrs => [
      'zimbraDomainName',
      'zimbraDomainType',
      'zimbraId',
      'zimbraAuthMechAdmin',
      'zimbraAuthMech',
      'zimbraAuthLdapSearchBindDn',
      'zimbraAuthLdapSearchBindPassword',
      'zimbraAuthLdapSearchFilter'
    ]
  );
  if ( $zim_domain_search->code ) {
    handle_error(
      $domain,
      'Zimbra domain lookup',
      $zim_domain_search->error
    );
    next DOMAIN
  }

  # We must have exactly 1 result
  if ( scalar $zim_domain_search->entries == 0 ) {
    if ( yaml_bool($conf->{domains}->{$domain}->{zimbra}->{create_if_missing}) ) {
      log_info( "Creating domain $domain" );
      ZmClient::sendZmprovRequest( "createDomain $domain " .
	                           build_domain_attrs($conf->{domains}->{$domain})
      );
    } else {
      handle_error(
        $domain,
	'Zimbra domain lookup',
	"Domain $domain doesn't exist in Zimbra"
      );
      next DOMAIN;
    }
  } elsif ( scalar $zim_domain_search->entries gt 1 ) {
    handle_error(
      $domain,
      'Zimbra domain lookup',
      "Found several matches for domain $domain"
    );
    next DOMAIN;
  }

  # Get LDAP entry representing the domain
  my $domain_entry = ldap2hashref( $zim_domain_search, 'zimbraDomainName' )->{$domain};

  # Check if auth is set to ad or ldap
  if (
      not defined $domain_entry->{zimbraAuthMech} or
      $domain_entry->{zimbraAuthMech} !~ m/^ad|ldap$/i
     ) {
    if ( yaml_bool( $conf->{domains}->{$domain}->{zimbra}->{setup_ldap_auth} ) ) {
      send_zmprov_cmd( "modifyDomain $domain " . build_domain_attrs( $conf->{domains}->{$domain} ) );
    } else {
      handle_error(
        $domain,
	'Domain external auth check',
	"domain $domain must be configured for LDAP or AD authentication first"
      );
      next DOMAIN;
    }
  }

  # Now lookup for domain aliases defined in Zimbra
  my $zim_domain_alias_search = $zim_ldap->ldap->search(
    filter => "(&(objectClass=zimbraDomain)(zimbraDomainAliasTargetId=" . $domain_entry->{zimbraId} . "))"
  );
  if ( $zim_domain_alias_search->code ) {
    handle_error(
      $domain,
      'Zimbra domain alias lookup',
      $zim_domain_alias_search->error
    );
    next DOMAIN;
  }

  $domain_entry->{zimbraDomainAliases} = [];
  foreach my $alias ( $zim_domain_alias_search->entries ) {
    push @{ $domain_entry->{zimbraDomainAliases} },
        $alias->get_value('zimbraDomainName');
  }

  log_verbose( "Trying to connect to " .
	         join( ' or ', @{ $conf->{domains}->{$domain}->{ldap}->{servers} } ) );

  my $ext_ldap = Net::LDAP->new( [ @{ $conf->{domains}->{$domain}->{ldap}->{servers} } ] );
  if ( not $ext_ldap ) {
    handle_error( $domain, 'External LDAP connection', $@ );
    next DOMAIN;
  }

  log_verbose( "Connection succeeded" );

  if ( yaml_bool( $conf->{domains}->{$domain}->{ldap}->{start_tls} ) ) {
    log_verbose( "Trying to switch to a secured connection using StartTLS" );
    my $tls = $ext_ldap->start_tls( verify => 'require' );
    if ( $tls->code ) {
      handle_error( $domain, 'External LDAP StartTLS', $tls->error );
      next DOMAIN;
    }

    log_verbose( "StartTLS succeeded" );
  }

  if ( defined $conf->{domains}->{$domain}->{ldap}->{bind_dn} and defined $conf->{domains}->{$domain}->{ldap}->{bind_pass} ) {
    log_verbose( "Trying to bind as " . $conf->{domains}->{$domain}->{ldap}->{bind_dn} );
    my $bind = $ext_ldap->bind(
      $conf->{domains}->{$domain}->{ldap}->{bind_dn},
      password => $conf->{domains}->{$domain}->{ldap}->{bind_pass}
    );
    if ( $bind->code ) {
      handle_error( $domain, 'External LDAP bind', $bind->error );
      next DOMAIN;
    }

    log_verbose( "Bind succeeded" );
  }

  my $zim_aliases = {};

  foreach my $domain_alias ( $domain, @{ $domain_entry->{zimbraDomainAliases} }) {
    log_verbose( "Searching for aliases in Zimbra for domain alias $domain_alias" );
    my $zim_aliases_search = $zim_ldap->ldap->search (
      base   => 'ou=people,' . domain2dn( $domain_alias ),
      filter => '(objectClass=zimbraAlias)',
      attrs  => [
        'zimbraAliasTargetId',
        'uid'
      ]
    );
    if ( $zim_aliases_search->code ) {
      handle_error(
        $domain,
	'Zimbra user and distribution lists alias lookup',
	$zim_aliases_search->error
      );
      next DOMAIN;
    }

    $zim_aliases->{$domain_alias} = ldap2hashref( $zim_aliases_search, 'uid' );
  }

  log_verbose( "Searching for potential users in " .
	       $conf->{domains}->{$domain}->{users}->{base} .
	       " matching filter " .
	       $conf->{domains}->{$domain}->{users}->{filter} );

  # List of attributes to fetch from LDAP
  # First, we want all the attributes which are mapped to Zimbra fields
  my $fetch_attrs = [ keys $conf->{domains}->{$domain}->{users}->{attr_map} ];

  # We also want the object key
  push $fetch_attrs, $conf->{domains}->{$domain}->{users}->{key};

  # If defined in the config, we need to get attribute containing email and aliases
  foreach ( qw( alias_attr mail_attr ) ) {
    next if ( not $conf->{domains}->{$domain}->{users}->{$_} );
    push $fetch_attrs, $conf->{domains}->{$domain}->{users}->{$_};
  }

  # Now we can run the lookup
  my $ext_user_search = $ext_ldap->search(
     base   => $conf->{domains}->{$domain}->{users}->{base},
     filter => $conf->{domains}->{$domain}->{users}->{filter},
     attrs  => $fetch_attrs
  );

  if ( $ext_user_search->code ) {
    handle_error(
      $domain,
      'External LDAP user lookup',
      $ext_user_search->error
    );
    next DOMAIN;
  }

  log_verbose( "Found " . scalar $ext_user_search->entries .
	       " users in external LDAP" );

  log_verbose( "Searching for users in Zimbra" );

  # Search for Zimbra users, but exclude known system accounts
  my $zim_user_search = $zim_ldap->ldap->search(
    base   => 'ou=people,' . $domain_entry->{dn},
    filter => '(&(objectClass=zimbraAccount)(!(zimbraIsSystemAccount=TRUE)))';
    attrs => [
      ( map { $conf->{domains}->{$domain}->{users}->{attr_map}->{$_} }
	       keys $conf->{domains}->{$domain}->{users}->{attr_map} ),
      ( 'uid',
	'zimbraAccountStatus',
	'zimbraAuthLdapExternalDn',
	'zimbraMailAlias',
	'mail',
	'zimbraNotes' )
    ]
  );
  if ( $zim_user_search->code ) {
    handle_error(
      $domain,
      'Zimbra users lookup',
      $zim_user_search->error
    );
    next DOMAIN;
  }

  log_verbose( "Found " . scalar $zim_user_search->entries .
	       " users in Zimbra" );

  log_verbose( "Comparing the accounts" );

  my @single = keys $conf->{domains}->{$domain}->{users}->{attr_map};
  push @single, $conf->{domains}->{$domain}->{users}->{mail_attr};
  my $ext_users = ldap2hashref(
    $ext_user_search,
    $conf->{domains}->{$domain}->{users}->{key},
    [ $conf->{domains}->{$domain}->{users}->{alias_attr} ],
    \@single
  );
  my $zim_users = ldap2hashref(
    $zim_user_search,
    'uid',
    [ 'mail' ]
  );

  # First loop : Check users which exist in external LDAP but not in Zimbra
  # or which exist in both but need to be updated
  foreach my $user ( keys $ext_users ) {
    my $attrs = '';
    if ( defined $zim_users->{$user} ) {

      # User exists in Zimbra, lets check its attribute are up to date
      foreach my $attr ( keys $conf->{domains}->{$domain}->{users}->{attr_map} ) {

        if ( not defined $ext_users->{$user}->{$attr} and
             not defined $zim_users->{$user}->{$conf->{domains}->{$domain}->{users}->{attr_map}->{$attr}} ) {
          # Attr does not exist in external LDAP and in Zimbra, no need to continue comparing them
          next;
        }
        if ( $conf->{domains}->{$domain}->{users}->{attr_map}->{$attr} ne 'sn' and
             not defined $ext_users->{$user}->{$attr} ) {
          # If the attribute doesn't exist in external LDAP, we must remove it from Zimbra.
          # Except for sn which is mandatory in Zimbra
          $attrs .= '-' . $conf->{domains}->{$domain}->{users}->{attr_map}->{$attr} . " " .
	            zim_attr_value( $zim_users->{$user}->{$conf->{domains}->{$domain}->{users}->{attr_map}->{$attr}} );
        } elsif (
                  ( $conf->{domains}->{$domain}->{users}->{attr_map}->{$attr} ne 'sn' and
                    $ext_users->{$user}->{$attr} ne ( $zim_users->{$user}->{$conf->{domains}->{$domain}->{users}->{attr_map}->{$attr}} || '' )
                  ) ||
                  $conf->{domains}->{$domain}->{users}->{attr_map}->{$attr} eq 'sn' and
                    defined $ext_users->{$user}->{$attr} and
                    $ext_users->{$user}->{$attr} ne ( $zim_users->{$user}->{$conf->{domains}->{$domain}->{users}->{attr_map}->{$attr}} || '' )
                ) {
            $attrs .= " " . $conf->{domains}->{$domain}->{users}->{attr_map}->{$attr} . " " .
	              zim_attr_value( $ext_users->{$user}->{$attr} );
            log_verbose( "Attribute $attr for user $user changed from " .
                       $zim_users->{$user}->{$conf->{domains}->{$domain}->{users}->{attr_map}->{$attr}} .
                       " to " .
                       $ext_users->{$user}->{$attr} );
        }
      }

      if (
          not defined $zim_users->{$user}->{zimbraAuthLdapExternalDn} or
          $zim_users->{$user}->{zimbraAuthLdapExternalDn} ne $ext_users->{$user}->{dn}
         ) {
        $attrs .= " zimbraAuthLdapExternalDn " . zim_attr_value( $ext_users->{$user}->{dn} );
      }

      if ( $attrs ne '' ) {
        # Some attribute must change, we need to update Zimbra
        log_verbose( "User $user has changed in external LDAP, updating it" );
        send_zmprov_cmd( "modifyAccount $user\@$domain $attrs" );
      }

    } else {
      # User exists in external LDAP but not in Zimbra. We must create it
      log_verbose( "User $user found in external LDAP but not in Zimbra. Will be created" );

      foreach my $attr ( keys $conf->{domains}->{$domain}->{users}->{attr_map} ) {
        next if (not defined $ext_users->{$user}->{$attr} or $ext_users->{$user}->{$attr} eq '');
        $attrs .= ' ' . $conf->{domains}->{$domain}->{users}->{attr_map}->{$attr} . " " .
                  zim_attr_value( $ext_users->{$user}->{$attr} );
      }
      $attrs .= " zimbraAuthLdapExternalDn " . zim_attr_value( $ext_users->{$user}->{dn} );
      # The password won't be used because Zimbra is set to use external LDAP/AD auth
      # But better to set it to a random value
      my $pass = $uuid->create_str;
      send_zmprov_cmd( "createAccount $user\@$domain $pass $attrs" );
    }

    my @ext_aliases = ();
    foreach my $mail_attr ( qw( mail_attr alias_attr ) ) {
      next if ( not defined $conf->{domains}->{$domain}->{users}->{$mail_attr} or
                not defined $ext_users->{$user}->{$conf->{domains}->{$domain}->{users}->{$mail_attr}} );
      push @ext_aliases,
             @{ $ext_users->{$user}->{$conf->{domains}->{$domain}->{users}->{$mail_attr}} };
    }

    @ext_aliases = uniq( sort @ext_aliases );

    foreach my $alias ( @ext_aliases ) {
      next if ( not alias_matches_domain( $alias, $domain_entry ) );
      next if ( grep { $alias eq $_ } @{ $zim_users->{$user}->{mail} } );
      log_verbose( "Creating alias $alias for user $user" );
      send_zmprov_cmd( "addAccountAlias $user $alias" );
    }

    # On each sync, we register the list of LDAP aliases into Zimbra's LDAP in the zimbraNotes attribute
    # We can compare if it has changed, and add/remove the aliases accordingly
    # This is not very clean, but at least allows the script to be "stateless"
    # and only relies on LDAP content on both sides. If only zimbraAlias objectClass allowed zimbraNotes attribute
    # it'd be easier
    my $ext_prev_aliases = parse_zimbra_notes( $zim_users->{$user}->{zimbraNotes} || '' )->{LDAP_Aliases};
    my @ext_prev_aliases = ( defined $ext_prev_aliases ) ? sort @{ $ext_prev_aliases } : ();
    my $alias_diff       = Array::Diff->diff( \@ext_prev_aliases, \@ext_aliases );

    foreach my $alias ( @{ $alias_diff->deleted } ) {
      my ( $al, $dom ) = split /\@/, $alias;
      next if ( not defined $zim_aliases->{$dom} or
	        not defined $zim_aliases->{$dom}->{$al} );
      log_verbose( "Removing LDAP alias $alias from user $user " .
	           "as it doesn't exist in LDAP anymore" );
      send_zmprov_cmd( "removeAccountAlias $user\@$domain $alias" );
    }

    my $note = $sync_from_ldap . "|LDAP_Aliases=" . join(',', @ext_aliases);
    if ( $note ne ($zim_users->{$user}->{zimbraNotes} || '') ) {
      send_zmprov_cmd( "modifyAccount $user\@$domain zimbraNotes " .
	               zim_attr_value( $note ) );
    }
  }

  # Second loop : we loop through the Zimbra users to check if they should be locked (if they don't exist in external LDAP anymore)
  foreach my $user ( keys $zim_users ) {
    # Make sure we only lock accounts if they don't exist anymore in external LDAP
    # has the zimbraNotes attribute set, with the expected value, and the account is active
    if ( not defined $ext_users->{$user} and
         defined $zim_users->{$user}->{zimbraNotes} and
         $zim_users->{$user}->{zimbraNotes} =~ m/^$sync_from_ldap/ and
         defined $zim_users->{$user}->{zimbraAccountStatus} and
         $zim_users->{$user}->{zimbraAccountStatus} =~ m/^active|lockout$/ ) {
      log_verbose( "User $user doesn't exist in external LDAP anymore, " .
                   "locking it in Zimbra" );
      send_zmprov_cmd( "modifyAccount $user\@$domain zimbraAccountStatus locked" );
    }
  }

  # Now, we try to sync groups in external LDAP into distribution lists in Zimbra
  if ( defined $conf->{domains}->{$domain}->{groups} ) {

    log_verbose( "Searching for potential groups in " .
               $conf->{domains}->{$domain}->{groups}->{base} .
               " matching filter " .
               $conf->{domains}->{$domain}->{groups}->{filter}
    );

    $fetch_attrs = [ keys $conf->{domains}->{$domain}->{groups}->{attr_map} ];
    push $fetch_attrs, $conf->{domains}->{$domain}->{groups}->{key};
    push $fetch_attrs, $conf->{domains}->{$domain}->{groups}->{members_attr};
    foreach ( qw( mail_attr alias_attr ) ) {
      next if ( not defined $conf->{domains}->{$domain}->{groups}->{$_} );
      push $fetch_attrs, $conf->{domains}->{$domain}->{groups}->{$_};
    }

    my $ext_group_search = $ext_ldap->search(
      base   => $conf->{domains}->{$domain}->{groups}->{base},
      filter => $conf->{domains}->{$domain}->{groups}->{filter},
      attrs  => $fetch_attrs
    );

    if ( $ext_group_search->code ) {
      handle_error( $domain, 'External LDAP groups lookup', $ext_group_search->error );
      next DOMAIN;
    }

    log_verbose( "Found " . scalar $ext_group_search->entries .
                 " groups in external LDAP" );

    log_verbose( "Searching for distribution lists in Zimbra" );

    # Search in Zimbra for distribution lists so we can compare with the groups in external LDAP
    my $zim_dl_search = $zim_ldap->ldap->search(
      base   => 'ou=people,' . $domain_entry->{dn},
      filter => "(objectClass=zimbraDistributionList)",
      attrs  => [
        ( map { $conf->{domains}->{$domain}->{groups}->{attr_map}->{$_} }
            keys $conf->{domains}->{$domain}->{groups}->{attr_map} ),
        (
          'uid',
	  'zimbraDistributionListSubscriptionPolicy',
	  'zimbraDistributionListUnsubscriptionPolicy',
          'zimbraMailForwardingAddress',
	  'zimbraNotes',
	  'zimbraMailStatus',
	  'mail'
        )
      ]
    );
    if ( $zim_dl_search->code ) {
      handle_error(
        $domain,
	'Zimbra distribution lists lookup',
	$zim_dl_search->error
      );
      next DOMAIN;
    }

    log_verbose( "Found " . scalar $zim_dl_search->entries .
	         " distribution list(s) in Zimbra" );
    log_verbose( "Comparing groups with distribution lists" );

    my @single = keys $conf->{domains}->{$domain}->{groups}->{attr_map};
    push @single, $conf->{domains}->{$domain}->{groups}->{mail_attr};

    my $ext_groups = ldap2hashref(
      $ext_group_search,
      $conf->{domains}->{$domain}->{groups}->{key},
      [
        $conf->{domains}->{$domain}->{groups}->{members_attr},
        $conf->{domains}->{$domain}->{groups}->{alias_attr}
      ],
      \@single
    );
    my $zim_dl = ldap2hashref(
      $zim_dl_search,
      'uid',
      [ 'zimbraMailForwardingAddress', 'mail' ]
    );

    # Build a dn2id hashref to lookup users or groups by their DN
    my $dn2id = {};
    $dn2id->{$ext_users->{$_}->{dn}}  = $_ foreach ( keys $ext_users );
    $dn2id->{$ext_groups->{$_}->{dn}} = $_ foreach ( keys $ext_groups );

    # First loop, check if every group in LDAP exists as a DL in Zimbra
    foreach my $group ( keys $ext_groups ) {
      if ( defined $zim_dl->{$group} ) {
        # A group match an existing DL, we must check its attributes

        my $attrs = '';
        foreach my $attr ( keys $conf->{domains}->{$domain}->{groups}->{attr_map} ) {
          if ( not defined $ext_groups->{$group}->{$attr} and
               not defined $zim_dl->{$group}->{$conf->{domains}->{$domain}->{groups}->{attr_map}->{$attr}} ) {
            # Attr does not exist in external LDAP and in Zimbra, not need to continue
            next;
          } elsif ( not defined $ext_groups->{$group}->{$attr} ) {
            # Attr doesn't exist in external LDAP, but exists in Zimbra. We must remove it
            $attrs = ' -' . $conf->{domains}->{$domain}->{groups}->{attr_map}->{$attr} . " " .
                     zim_attr_value( $zim_dl->{$group}->{$conf->{domains}->{$domain}->{groups}->{attr_map}->{$attr}} );
          } elsif ( $ext_groups->{$group}->{$attr} ne $zim_dl->{$group}->{$conf->{domains}->{$domain}->{groups}->{attr_map}->{$attr}} ) {
            # Attr exists in both but doesn't match
            $attrs .= " " . $conf->{domains}->{$domain}->{groups}->{attr_map}->{$attr} . " " .
                      zim_attr_value( $ext_groups->{$group}->{$attr} );
            log_verbose( $ext_groups->{$group}->{$attr} . " vs " .
		         $zim_dl->{$group}->{$conf->{domains}->{$domain}->{groups}->{attr_map}->{$attr}} );
          }
        }

        # Users cannot subscribe or unsubscribe from LDAP group
        if ( not defined $zim_dl->{$group}->{zimbraDistributionListSubscriptionPolicy} or
             $zim_dl->{$group}->{zimbraDistributionListSubscriptionPolicy} ne 'REJECT' ) {
          $attrs .= " zimbraDistributionListSubscriptionPolicy REJECT";
        }
        if ( not defined $zim_dl->{$group}->{zimbraDistributionListUnsubscriptionPolicy} or
             $zim_dl->{$group}->{zimbraDistributionListUnsubscriptionPolicy} ne 'REJECT' ) {
          $attrs .= " zimbraDistributionListUnsubscriptionPolicy REJECT";
        }

        # If the group in LDAP has a mail defined, enable mail delivery in Zimbra. Else, disable it
        my $mail_status = ( defined $ext_groups->{$group}->{$conf->{domains}->{$domain}->{groups}->{mail_attr}} ) ?
	                    'enabled' : 'disabled';
        if ( not defined $zim_dl->{$group}->{zimbraMailStatus} or
             $zim_dl->{$group}->{zimbraMailStatus} ne $mail_status ) {
          $attrs .= " zimbraMailStatus $mail_status";
        }

        if ( $attrs ne '' ) {
          # Some attribute must change, lets update Zimbra
          log_verbose( "Group $group has changed in external LDAP, updating it" );
          send_zmprov_cmd( "modifyDistributionList $group\@$domain $attrs" );
        }

      } else {
        # A new group with no corresponding DL in Zimbra
        log_verbose( "Found a new group : $group. Creating it in Zimbra" );
        my $attrs = '';
        foreach my $attr ( keys $conf->{domains}->{$domain}->{groups}->{attr_map} ) {
          next if ( not defined $ext_groups->{$group}->{$attr} or
                    $ext_groups->{$group}->{$attr} eq '');
          $attrs .= ' ' . $conf->{domains}->{$domain}->{groups}->{attr_map}->{$attr} . " " .
                    zim_attr_value( $ext_groups->{$group}->{$attr} );
        }
        $attrs .= " zimbraDistributionListUnsubscriptionPolicy REJECT";
        $attrs .= " zimbraDistributionListSubscriptionPolicy REJECT";
        my $mail_status = ( defined $ext_groups->{$group}->{$conf->{domains}->{$domain}->{groups}->{mail_attr}} ) ?
                            'enabled' : 'disabled';
        $attrs .= " zimbraMailStatus $mail_status";
        send_zmprov_cmd( "createDistributionList $group\@$domain $attrs" );
      }

      # Now that all the needed groups exist as distribution list, we need to handle membership
      # For that, we must convert the membership list of the external group to the same format as Zimbra
      my @ext_members = ();

      if ( not yaml_bool( $conf->{domains}->{$domain}->{groups}->{members_as_dn} ) ) {
        # If members are not listed as full DN, but by uid, simply concat it with the domain
        foreach my $member ( @{ $ext_groups->{$group}->{$conf->{domains}->{$domain}->{groups}->{members_attr}} } ) {
          if ( not defined $ext_users->{$member} ) {
            log_verbose( "Skiping member $member of group $group as it doesn't match a Zimbra user" );
            next;
          }
          next if ( not defined $ext_users->{$member} and
                    not defined $ext_groups->{$member} );
          push @ext_members, $member . '@' . $domain;
        }
      } else {
        # If members are listed as full DN, we need to lookup in the dn2id we prepared earlier
        foreach my $member ( @{ $ext_groups->{$group}->{$conf->{domains}->{$domain}->{groups}->{members_attr}} } ) {
          next if ( not defined $dn2id->{$member} );
          push @ext_members, $dn2id->{$member} . '@' . $domain;
        }
      }
      @ext_members = sort @ext_members;
      my @zim_members = ( defined $zim_dl->{$group}->{zimbraMailForwardingAddress} ) ?
                          sort @{$zim_dl->{$group}->{zimbraMailForwardingAddress}} : ();

      # Now we can compare members for this group in external LDAP and Zimbra
      my $diff = Array::Diff->diff( \@ext_members, \@zim_members );

      if ( scalar @{ $diff->deleted } gt 0 ){
        send_zmprov_cmd( "addDistributionListMember $group\@$domain " .
          join (' ', @{ $diff->deleted } ) );
      }
      if ( scalar @{ $diff->added } gt 0 ) {
        send_zmprov_cmd( "removeDistributionListMember $group\@$domain $_")
          foreach ( @{ $diff->added } );
      }
      my @ext_aliases = ();
      foreach my $mail_attr ( qw( mail_attr alias_attr ) ) {
        next if ( not defined $conf->{domains}->{$domain}->{groups}->{$mail_attr} or
                  not defined $ext_groups->{$group}->{$conf->{domains}->{$domain}->{groups}->{$mail_attr}} );
        push @ext_aliases,
               @{ $ext_groups->{$group}->{$conf->{domains}->{$domain}->{groups}->{$mail_attr}} };
      }
      @ext_aliases = uniq( sort @ext_aliases );
      foreach my $alias ( @ext_aliases ) {
        next if ( not alias_matches_domain( $alias, $domain_entry ) );
        next if ( grep { $alias eq $_ } @{ $zim_dl->{$group}->{mail} } );
        log_verbose( "Creating alias $alias for group $group" );
        send_zmprov_cmd( "addDistributionListAlias $group\@$domain $alias" );
      }

      # Now, check the diff between the list of LDAP alias for this users with the previous run
      my $ext_prev_aliases = parse_zimbra_notes( $zim_dl->{$group}->{zimbraNotes} || '' )->{LDAP_Aliases};
      my @ext_prev_aliases = ( defined $ext_prev_aliases ) ? sort @{ $ext_prev_aliases } : ();
      my $alias_diff       = Array::Diff->diff( \@ext_prev_aliases, \@ext_aliases );

      foreach my $alias ( @{ $alias_diff->deleted } ) {
        my ( $al, $dom ) = split /\@/, $alias;
        next if ( not defined $zim_aliases->{$dom} or
                  not defined $zim_aliases->{$dom}->{$al} );
        log_verbose( "Removing LDAP alias $alias from distribution list $group " .
                     "as it doesn't exist in LDAP anymore" );
        send_zmprov_cmd( "removeDistributionListAlias $group\@$domain $alias" );
      }

      my $note = $sync_from_ldap . "|LDAP_Aliases=" . join(',', @ext_aliases);
      if ( $note ne ($zim_dl->{$group}->{zimbraNotes} || '') ) {
        send_zmprov_cmd( "modifyDistributionList $group\@$domain zimbraNotes " .
                         zim_attr_value( $note ) );
      }
    }

    # Now, look at all the distribution list which were created from LDAP but doesn't exist anymore in LDAP
    foreach my $dl ( keys $zim_dl ) {
      next if ( not defined $zim_dl->{$dl}->{zimbraNotes} or
                $zim_dl->{$dl}->{zimbraNotes} !~ m/^$sync_from_ldap/ );
      next if ( defined $ext_groups->{$dl} );
      log_verbose( "Group $dl doesn't exist in LDAP anymore, " .
                   "removing the corresponding distribution list" );
      send_zmprov_cmd( "deleteDistributionList $dl\@$domain" );
    }
  }
}

# zmprov breaks terminal (no echo to your input after execution)
# fix it with a tset
system('tset');

# Exit with the global exit code (if at least one domain had an error, it'll be != 0)
exit $exit;


###### Subroutines ######

# Print usage
sub usage {
  print <<_EOF;

Usage: $0 [ --config /path/to/config.yml ] [ --dry-run ] [ --quiet ] [ --verbose ]

With:
  * -c|--config : designate the path of the config file to use. Default is /opt/zimbra/conf/ldap_sync.yml
  * -d|--dry-run : do not change anything, only prints what would be done
  * -q|--quiet : No output except if there are errors
  * -v|--verbose : extra output (not only if something is to be updated in Zimbra)

_EOF
}

# Print messages only if the verbose flag was given
sub log_verbose {
  my $msg = shift;
  print $msg . "\n" if ( $opt->{verbose} );
}

# Print info messages unless the quiet flag was given
sub log_info {
  my $msg = shift;
  print $msg . "\n" if ( not $opt->{quiet} );
}

# Print errors
sub log_error {
  my $msg = shift;
  print $msg . "\n";
}

# Just a helper to handle error. Will print the error
# send an email to the admin if nedded, and set an exit code
sub handle_error {
  my $domain = shift;
  my $step   = shift;
  my $err    = shift;

  log_error( $err );
  if ( defined $conf->{general}->{notify}->{to} ) {
    my $mail   = Email::MIME->create(
      header_str => [
        From    => $conf->{general}->{notify}->{from},
        To      => $conf->{general}->{notify}->{to},
        Subject => "Zimbra LDAP synchronisation error for domain $domain"
      ],
      attributes => {
        charset  => 'utf-8',
        encoding => 'base64'
      },
      body_str => "LDAP synchronisation for domain $domain failed at step '$step'. The error was\n$err\n",
    );
    my $transport = Email::Sender::Transport::Sendmail->new({
      sendmail => '/opt/zimbra/common/sbin/sendmail'
    });
    sendmail( $mail, { transport => $transport } );
  }
  $exit = 255;
}

# ldap2hashref takes three args
#  * An LDAP search result
#  * The attribute used as the key of objects
#  * An optional array of attributes we want as an array, even if there's a single value
#  * An optional array of attributes we want single valued. Return the first value if several are provided
# It'll return a hashref. The key will be unaccentuated and lower cased.

sub ldap2hashref {
  my $search      = shift;
  my $key         = shift;
  my $want_array  = shift;
  my $want_single = shift;
  my $return      = {};

  $want_array  ||= [];
  $want_single ||= [];

  foreach my $entry ( $search->entries ) {
    $return->{unidecode( lc $entry->get_value($key) )}->{dn} = $entry->dn;
    foreach my $attr ( $entry->attributes ) {
      my @values = $entry->get_value($attr);
      if ( grep { $attr eq $_ } @{ $want_array } ) {
        $return->{unidecode( lc $entry->get_value($key) )}->{$attr} = \@values;
      } elsif ( grep { $attr eq $_ } @{ $want_single } ) {
        $return->{unidecode( lc $entry->get_value($key) )}->{$attr} = $values[0];
      } else {
        $return->{unidecode( lc $entry->get_value($key) )}->{$attr} = ( scalar @values == 1 ) ?
	                                                                $values[0] : \@values;
      }
    }
  }
  return $return;
}

# Check YAML bool, and return either 1 or 0
sub yaml_bool {
  my $bool = shift;
  if ( $bool =~ m/^y|yes|true|1|on$/i ) {
    return 1;
  } else {
    return 0;
  }
}

# Build a string to pass to zmprov to configure a domain
# Takes the domain conf hashref as only arg
sub build_domain_attrs {
  my $domain_conf = shift;
  my $type = ( $domain_conf->{ldap}->{schema} =~ m/^ad/i ) ? 'ad' : 'ldap';
  my $attrs = "zimbraAuthMech " . zim_attr_value( $type );
  $attrs .= " zimbraAuthMechAdmin " . zim_attr_value( $type );
  if ( defined $domain_conf->{ldap}->{bind_dn} and
       defined $domain_conf->{ldap}->{bind_pass} ) {
     $attrs .= " zimbraAuthLdapSearchBindDn " . zim_attr_value( $domain_conf->{ldap}->{bind_dn} );
     $attrs .= " zimbraAuthLdapSearchBindPassword " . zim_attr_value( $domain_conf->{ldap}->{bind_pass} );
  }
#  if ( defined $domain_conf->{users}->{filter} ) {
#    $attrs = " zimbraAuthLdapSearchFilter " . zim_attr_value( "(&(|(" . $domain_conf->{users}->{key} . "=%u)(" . $domain_conf->{users}->{key} . "=%n))(" . $domain_conf->{users}->{filter} . ")" );
#  }
  $attrs .= " zimbraAuthLdapURL " .
            join( ' +zimbraAuthLdapURL', @{ $domain_conf->{ldap}->{servers} } );
  if ( defined $domain_conf->{ldap}->{start_tls} and
       yaml_bool( $domain_conf->{ldap}->{start_tls} ) ) {
    $attrs .= " zimbraAuthLdapStartTlsEnabled TRUE";
  } else {
    $attrs .= " zimbraAuthLdapStartTlsEnabled FALSE";
  }
  return $attrs;
}

# Takes a domain name as arg and return its DN in Zimbra LDAP directory
sub domain2dn {
  my $domain = shift;
  $domain =~ s/\./,dc=/g;
  return 'dc=' . $domain;
}

# Prepare a string to be used as arg to zmprov
sub zim_attr_value {
  my $value = shift;
  utf8::encode($value);
  return shell_quote($value);
}

# Take an alias and a domain. Return 1 if the alias is member of this domain (or one of the domain aliases)
sub alias_matches_domain {
  my $alias  = shift;
  my $domain = shift;
  return 1 if ( $alias =~ m/\@$domain->{zimbraDomainName}$/ );
  foreach my $dom ( @{ $domain->{zimbraDomainAliases} } ) {
    return 1 if ( $alias =~ m/\@$dom$/ );
  }
  return 0;
}

# Send a command to zmprov
sub send_zmprov_cmd {
  my $cmd = shift;
  log_info( "Sending command zmprov " . $cmd );
  if ( not $opt->{dry} ) {
    ZmClient::sendZmprovRequest( $cmd );
  }
}

# Parse the zimbraNotes field and return the content as a hashref
sub parse_zimbra_notes {
  my $notes = shift;
  my $return = {};
  return $return if ( $notes !~ m/^$sync_from_ldap/ );
  $notes =~ s/^$sync_from_ldap//;
  foreach my $rec ( split /\|/, $notes ) {
    next if not ( $rec =~ m/^([^=\|]+)=(([^,\|]+,?)+)/ );
    my ( $key, $values ) = ( $1, $2 );
    $return->{$key} = [ split /,/, $values ];
  }
  return $return;
}

# Set default config values if missing
sub get_default_conf {
  my $conf = shift;
  my $default = {};
  if ( $conf->{ldap}->{schema} eq 'ad' ) {

    $defaults = {
      ldap => {
        type      => 'ad',
        start_tls => 1
      },
      users => {
        filter     => '(&(objectClass=user)(mail=*))',
        key        => 'sAMAccountName',
        mail_attr  => 'mail',
        alias_attr => 'otherMailbox',
        attr_map   => {
          displayName     => 'displayName',
          description     => 'description',
          cn              => 'cn',
          sn              => 'sn',
          givenName       => 'givenName',
          telephoneNumber => 'telephoneNumber',
          homePhone       => 'homePhone',
          mobile          => 'mobile',
          streetAddress   => 'street',
          l               => 'l',
          st              => 'st',
          co              => 'co',
          title           => 'title',
          company         => 'company'
        }
      },
      groups => {
        filter            => '(objectClass=group)',
        key               => 'cn',
        members_attr      => 'member',
        members_as_dn     => 1,
        mail_attr         => 'mail',
        alias_attr        => 0,
        attr_map          => {
          displayName => 'displayName',
          description => 'description'
        }
      }
    };

  } elsif ( $conf->{ldap}->{schema} eq 'rfc2307bis' ) {

    $defaults = {
      ldap => {
        type      => 'ldap',
        start_tls => 1
      },
      users => {
        filter     => '(&(objectClass=inetOrgPerson)(mail=*))',
        key        => 'uid',
        mail_attr  => 'mail',
        alias_attr => 'mail',
        attr_map   => {
          displayName     => 'displayName',
          description     => 'description',
          cn              => 'cn',
          sn              => 'sn',
          givenName       => 'givenName',
          telephoneNumber => 'telephoneNumber',
          mobile          => 'mobile',
          streetAddress   => 'street',
          l               => 'l',
          street          => 'st',
          title           => 'title',
          o               => 'company'
        }
      },
      groups => {
        filter            => '(objectClass=groupOfNames)',
        key               => 'cn',
        members_attr      => 'member',
        members_as_dn     => 1,
        mail_attr         => 0,
        alias_attr        => 0,
        attr_map          => {
          displayName => 'displayName',
          description => 'description'
        }
      }
    };

  } elsif ( $conf->{ldap}->{schema} eq 'rfc2307' ) {

    $defaults = {
      ldap => {
        type      => 'ldap',
        start_tls => 1
      },
      users => {
        filter     => '(&(objectClass=inetOrgPerson)(mail=*))',
        key        => 'uid',
        mail_attr  => 'mail',
        alias_attr => 'mail',
        attr_map   => {
          displayName     => 'displayName',
          description     => 'description',
          cn              => 'cn',
          sn              => 'sn',
          givenName       => 'givenName',
          telephoneNumber => 'telephoneNumber',
          mobile          => 'mobile',
          streetAddress   => 'street',
          l               => 'l',
          street          => 'st',
          title           => 'title',
          o               => 'company'
        }
      },
      groups => {
        filter            => '(objectClass=posixGroup)',
        key               => 'cn',
        members_attr      => 'memberUid',
        members_as_dn     => 0,
        mail_attr         => 0,
        alias_attr        => 0,
        attr_map          => {
          displayName => 'displayName',
          description => 'description' 
        }
      }
    };
  }

  $defaults->{zimbra} = {
    create_if_missing => 0,
    setup_ldap_auth   => 0
  };

  # If some attribute mapping is defined in the provided conf
  # do not use defaults
  foreach my $type ( qw( users groups ) ) {
    $defaults->{$type}->{attr_map} = {} if ( defined $conf->{$type}->{attr_map} );
  }
  return merge $defaults, $conf;
}