#!/usr/local/cpanel/3rdparty/bin/perl

# cpanel - scripts/generate_maildirsize            Copyright 2022 cPanel, L.L.C.
#                                                           All rights reserved.
# copyright@cpanel.net                                         http://cpanel.net
# This code is subject to the cPanel license. Unauthorized copying is prohibited

use strict;
use warnings;

use Cpanel::Usage                        ();
use Cpanel::PwCache::Helpers             ();
use Cpanel::PwCache::Build               ();
use Cpanel::PwCache                      ();
use Cpanel::JSON                         ();    # PPI USE OK - speed up loaduserdomains
use Cpanel::AccessIds::ReducedPrivileges ();
use Cpanel::Config::LoadCpUserFile       ();
use Cpanel::Config::HasCpUserFile        ();
use Cpanel::Config::Users                ();
use Cpanel::Config::LoadCpConf           ();
use Cpanel::Config::LoadUserDomains      ();
use Cpanel::Email::DiskUsage             ();
use Cpanel::Email::Maildir::Utils        ();
use Cpanel::Email::Maildir               ();
use Cpanel::Email::Mailbox               ();
use Cpanel::AdminBin::Serializer         ();    # PPI USE OK - speed up loaduserdomains
use Try::Tiny;

my $onlyrecalculate = 0;
my $verbose         = 0;
my $rename          = 0;
my $confirm         = 0;
my $allaccounts     = 0;

# Max quota is actually 1 byte less than get_max_email_quota
# but we'll silently fix the 1 byte issue below
my $max_quota = Cpanel::Email::Maildir::get_max_email_quota();

# Argument processing
my %opts = (
    'onlyrecalculate' => \$onlyrecalculate,
    'verbose'         => \$verbose,
    'rename'          => \$rename,
    'confirm'         => \$confirm,
    'allaccounts'     => \$allaccounts,
);

Cpanel::Usage::wrap_options( \@ARGV, \&usage, \%opts );

# When we are regenerating files we must tell Cpanel::Email::DiskUsage to ignore
# the existing maildirsize files or they will be used to regenerate themselves.
local $Cpanel::Email::DiskUsage::IGNORE_MAILDIRSIZE_FILES = 1;
local $Cpanel::Email::DiskUsage::VERBOSE                  = $verbose;

if ( $> == 0 && !$confirm ) {
    print "Must specify \"--confirm\" to begin. Please read and understand the usage.\n\n";
    usage(1);
}
umask(0077);    # Keep maildirsize file perms consistent with Exim

my $cpconf = Cpanel::Config::LoadCpConf::loadcpconf_not_copy();

my $pwcache_ref;
my %CPUSERS;
my $userdomains_ref = {};
my $suid            = 0;

if ( $> == 0 ) {
    $suid = 1;
    Cpanel::PwCache::Helpers::no_uid_cache();    #uid cache only needed if we are going to make lots of getpwuid calls
    Cpanel::PwCache::Build::init_passwdless_pwcache();
    $pwcache_ref = Cpanel::PwCache::Build::fetch_pwcache();
    my $users_arr_ref = Cpanel::Config::Users::getcpusers();
    $userdomains_ref = Cpanel::Config::LoadUserDomains::loaduserdomains( undef, 0, 1 );

    %CPUSERS = map { $_ => undef } @{$users_arr_ref};
    if ( @ARGV && $ARGV[-1] !~ m/^-/ ) {
        if ( exists $CPUSERS{ $ARGV[-1] } ) {
            %CPUSERS     = ( $ARGV[-1] => 1 );    #only do one user
            $allaccounts = 1;                     # Specified because a user was provided and they may or may not be using boxtrapper
        }
        else {
            %CPUSERS = ();
        }
    }
}
else {
    $rename      = 1;
    $allaccounts = 1;
    my @PW = Cpanel::PwCache::getpwuid_noshadow($>);
    $pwcache_ref = [ \@PW ];
    %CPUSERS     = ( $PW[0] => 1 );
    die "Unable to load cPanel user data.\n" unless Cpanel::Config::HasCpUserFile::has_cpuser_file( $PW[0] );
    my $user_info = Cpanel::Config::LoadCpUserFile::loadcpuserfile( $PW[0] );    #we want to load the default so we can use the storable cache

    if ( !scalar keys %{$user_info} ) {
        die "Unable to load cPanel user data.\n";
    }

    my @DOMAINS = ( $user_info->{'DOMAIN'} );

    if ( ref $user_info->{'DOMAINS'} ) {
        push @DOMAINS, @{ $user_info->{'DOMAINS'} };
    }
    $userdomains_ref->{ $PW[0] } = \@DOMAINS;
}

my $mailgid = ( Cpanel::PwCache::getpwnam('mailnull') )[3];
if ( !$mailgid ) {
    $mailgid = ( Cpanel::PwCache::getpwnam('mail') )[3];
    if ( !$mailgid ) {
        die "!! Unable to determine mail user GID !!\n";
    }
}

Cpanel::PwCache::Build::pwclearcache();

foreach my $pwref (@$pwcache_ref) {
    my ( $user, $useruid, $usergid, $homedir ) = (@$pwref)[ 0, 2, 3, 7 ];
    my @recalc_list;
    next if ( !exists $CPUSERS{$user} );
    if ( !$homedir || !-d $homedir ) {
        print "Skipping $user - (no home directory)\n";
        next;
    }

    my @DOMAINS = ref $userdomains_ref->{$user} ? @{ $userdomains_ref->{$user} } : ();
    my @check_list;

    #The main user
    my $check_main_user = 0;
    if ( !$allaccounts && !-e $homedir . '/etc/.boxtrapperenable' ) {
        print "Skipping user $user (Not using BoxTrapper)\n" if $verbose;
    }
    else {
        if ($onlyrecalculate) {
            if ( -e $homedir . '/mail/maildirsize' ) {
                if ( ( stat(_) )[7] >= 5120 ) {
                    print "Recalculating user $user (maildirsize file >= 5120 bytes)\n" if $verbose;
                    $check_main_user = 1;
                }
                elsif ( ( stat(_) )[7] == 0 ) {
                    print "Recalculating user $user (maildirsize file == 0 bytes)\n" if $verbose;
                    $check_main_user = 1;
                }
                else {
                    print "Skipping user $user (maildirsize file already exists and is not >= 5120 bytes)\n" if $verbose;
                }
            }
            else {
                $check_main_user = 1;
            }
        }

        # Passed flags for all accounts and not to only recalculate
        else {
            $check_main_user = 1;
        }
    }

    foreach my $domain ( grep { $_ } @DOMAINS ) {

        # We avoid try/catch here for speed since on an up to date
        # system its most of the execution time.
        local $@;
        my @users = eval { Cpanel::Email::Maildir::Utils::get_maildir_users_under_dir( $homedir . '/mail/' . $domain ); };
        if ($@) {
            warn;
            next;
        }

        foreach my $mail_user (@users) {
            if ( !$allaccounts && !-e $homedir . '/etc/' . $domain . '/' . $mail_user . '/.boxtrapperenable' ) {
                print "Skipping user $mail_user\@$domain (Not using BoxTrapper)\n" if $verbose;
                next;
            }
            if ($onlyrecalculate) {
                if ( -e $homedir . '/mail/' . $domain . '/' . $mail_user . '/maildirsize' ) {
                    if ( ( stat(_) )[7] >= 5120 ) {
                        print "Recalculating mail user $mail_user\@$domain (maildirsize file >= 5120 bytes)\n" if $verbose;
                        push @check_list, $mail_user . '@' . $domain;
                    }
                    elsif ( ( stat(_) )[7] == 0 ) {
                        print "Recalculating mail user $mail_user\@$domain (maildirsize file == 0 bytes)\n" if $verbose;
                        push @check_list, $mail_user . '@' . $domain;
                    }
                    else {
                        print "Skipping mail user $mail_user\@$domain (maildirsize file already exists and is not >= 5120 bytes)\n" if $verbose;
                        next;
                    }
                }
                else {
                    push @check_list, $mail_user . '@' . $domain;
                }
            }

            # Passed flags for all accounts and not to only recalculate
            else {
                push @check_list, $mail_user . '@' . $domain;
            }
        }
    }
    if ( !@check_list && !$check_main_user ) {
        if ($verbose) { print "Skipping $user as there are no files to unlink or recalculate.\n"; }
        next;
    }
    if ($verbose) {
        if ($check_main_user) {
            print "Rebuilding the maildirsize files for: $user\n";
        }
        if (@check_list) {
            print "Rebuilding the maildirsize files for: " . join( ',', @check_list ) . "\n";
        }
    }

    # This will result in the main user's maildirsize file being wrong, so we
    # need to do it before generating the maildirsize file.
    unlink("$homedir/mail/dovecot-quota");
    _recalc_quota_or_warn($user) unless $onlyrecalculate;

    my $generate_coderef = sub {

        #All the domains
        # Only setuids after we actually have something do to?

        if ($check_main_user) {

            if ( Cpanel::Email::Mailbox::looks_like_mdbox("$homedir/mail") ) {
                print "Skipping user $user (using mdbox)\n" if $verbose;
            }
            else {
                print "Checking user $user\n" if $verbose;
                my ( $size, $count ) = Cpanel::Email::DiskUsage::mainacctdiskused( $homedir, $homedir . '/mail/maildirsize', $rename );
                if ( open my $mdsize_fh, '>', $homedir . '/mail/maildirsize' ) {
                    print 'Writing ' . $homedir . '/mail/maildirsize' . " for user $user\n" if $verbose;

                    print {$mdsize_fh} "0S,0C\n";
                    print {$mdsize_fh} $size . ' ' . $count . "\n";

                    close $mdsize_fh;
                    chown $useruid, $mailgid, $homedir . '/mail/maildirsize';
                    chmod 0600, $homedir . '/mail/maildirsize';
                }
                else {
                    warn "Unable to write: $homedir/mail/maildirsize: $!";
                }
            }
        }

        my %DOMAIN_QUOTAS;
        foreach my $email (@check_list) {

            my ( $mail_user, $domain ) = split( /\@/, $email, 2 );
            my $quota_ref = exists $DOMAIN_QUOTAS{$domain} ? $DOMAIN_QUOTAS{$domain} : ( $DOMAIN_QUOTAS{$domain} = _get_mail_domain_quota( $homedir, $domain ) );

            if ( Cpanel::Email::Mailbox::looks_like_mdbox( $homedir . '/mail/' . $domain . '/' . $mail_user ) ) {
                print "Skipping user $mail_user\@$domain (using mdbox)\n" if $verbose;
                next;
            }
            print "Checking user $mail_user\@$domain\n" if $verbose;

            my ( $size, $count ) = Cpanel::Email::DiskUsage::recalculate_email_account_disk_usage( $homedir, $mail_user, $domain, $homedir . '/mail/' . $domain . '/' . $mail_user . '/maildirsize', $rename );
            if ( open my $mdsize_fh, '>', $homedir . '/mail/' . $domain . '/' . $mail_user . '/maildirsize' ) {
                print 'Writing ' . $homedir . '/mail/' . $domain . '/' . $mail_user . '/maildirsize' . " for user $mail_user\n" if $verbose;

                if ( !exists $quota_ref->{$mail_user} || !$quota_ref->{$mail_user} ) {
                    print {$mdsize_fh} "0S,0C\n";
                }
                else {
                    print {$mdsize_fh} sprintf( "%.0f", $quota_ref->{$mail_user} ) . "S,0C\n";
                }

                print {$mdsize_fh} $size . ' ' . $count . "\n";

                close $mdsize_fh;
                chown $useruid, $mailgid, $homedir . '/mail/' . $domain . '/' . $mail_user . '/maildirsize';
                chmod 0600, $homedir . '/mail/' . $domain . '/' . $mail_user . '/maildirsize';
                unlink("$homedir/mail/$domain/$mail_user/dovecot-quota");
                push @recalc_list, $mail_user . '@' . $domain unless $onlyrecalculate;
            }
            else {
                warn "Unable to write: $homedir/mail/$domain/$mail_user/maildirsize: $!";
            }
        }
        return 1;    # must return true
    };

    if ($suid) {
        eval { Cpanel::AccessIds::ReducedPrivileges::call_as_user( $generate_coderef, $useruid, $usergid ) } || warn "Could not setuid to $user: $@";
    }
    else {
        $generate_coderef->();
    }

    _recalc_quota_or_warn($_) for (@recalc_list);
}

sub _get_mail_domain_quota {
    my $homedir = shift;
    my $domain  = shift;
    my $dir     = $homedir . '/etc/' . $domain;

    return if !-f $dir . '/quota' || -z _;

    my %quota;
    if ( open my $quota_fh, '<', $dir . '/quota' ) {
        while ( my $line = readline $quota_fh ) {
            chomp $line;
            my ( $user, $quota ) = split( /:/, $line, 2 );

            # Quota values above $max_quota will be converted to unlimited
            next if !$user || !$quota || ( int $quota ) > $max_quota;

            # Remove 1 byte for quota values equal to $max_quota
            $quota = ( int $quota ) == $max_quota ? $max_quota - 1 : $quota;

            $quota{$user} = $quota;
        }
        close $quota_fh;
    }

    #ALWAYS RETURN HASHREF
    return \%quota;
}

sub _recalc_quota_or_warn {
    my ($account) = @_;

    require Cpanel::Dovecot::Utils if !$INC{'Cpanel/Dovecot/Utils.pm'};
    my $ret;
    try {
        $ret = Cpanel::Dovecot::Utils::recalc_quota( 'account' => $account );
    }
    catch {
        local $@ = $_;
        warn;
    };
    return $ret;
}

sub usage {
    my ($exit) = @_;
    $exit = $exit ? 1 : 0;

    print <<'EOM';
Usage: generate_maildirsize <modifier> <user>

This utility regenerates maildirsize files used by the maildir+
capable clients to assist in mailbox size calculations.

Modifier Flags:
    --confirm - This flag indicates that we really want to use this
        utility

    --allaccounts - This utility was originally intended to
        assist cPanel BoxTrapper with updating maildirsize
        files. Without this optional flag, generate_maildirsize
        will only operate on BoxTrapper enabled accounts.

    --rename - This optional flag indicates that the utility
        should rename individual message files to include the
        message size in the filename. This addition to the
        file name format is supported by Exim and greatly
        improves Exim's ability to update the maildirsize
        file.  POP3 accounts that store mail on the server may
        be forced to download their messages again if this
        option is used.

    --verbose - This optional flag turns on verbose mode for
        enhanced activity reporting to STDOUT.

    --onlyrecalculate - This optional flag turns will cause generate_maildirsize to
        only regenerate maildirsize files that are missing or are larger then 5120
        bytes.

    --help - display this message and exit.

EOM
    exit $exit;
}