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

# cpanel - scripts/vps_optimizer                   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

package scripts::vps_optimzer;

use strict;
use warnings;

use Try::Tiny;
use Pod::Usage   ();
use Getopt::Long ();

use Cpanel::LoadFile                      ();
use Cpanel::Exception                     ();
use Cpanel::ArrayFunc::Uniq               ();
use Cpanel::FileUtils::TouchFile          ();
use Cpanel::Transaction::File::LoadConfig ();

our $version      = '2.0';
our $CPSPAMD_PATH = '/etc/cpspamd.conf';

exit __PACKAGE__->new()->run_from_command_line(@ARGV) unless caller();

sub new {
    my $class = shift;
    return bless {}, $class;
}

sub run_from_command_line {
    my ( $self, @cmdline_args ) = @_;

    die Cpanel::Exception::create('RootRequired')->to_string_no_id() unless ( $> == 0 && $< == 0 );

    $self->{'opts'} = _parse_and_validate_opts( \@cmdline_args );

    # -1 to get the right exit code
    return Pod::Usage::pod2usage( -exitval => 'NOEXIT', -output => \*STDOUT, -verbose => 99, -sections => [qw(NAME DESCRIPTION SYNOPSIS)] ) - 1
      if $self->{'opts'}->{'help'};

    return 1 if !$self->_validate_environment();
    return 0 if !$self->_should_run_on_environment();

    my $changes  = $self->determine_changes_to_be_made();
    my $restarts = $self->make_changes($changes);

    $self->_restart_services($restarts);
    $self->_mark_run_complete();

    return 0;
}

sub determine_changes_to_be_made {
    my $self = shift;

    # defaults used in the previous version
    my $changes = {
        'conserve_memory' => 1,
        'spamd_config'    => {
            'maxspare'    => 1,
            'maxchildren' => 3,
        }
    };

    require Cpanel::Sys::Hardware::Memory;
    my $mem_on_system = Cpanel::Sys::Hardware::Memory::get_installed();    # returns MiB

    if ( $mem_on_system > 1500 ) {
        $changes->{'conserve_memory'} = 0;

        if ( $mem_on_system < 2500 ) {
            $changes->{'spamd_config'}->{'maxspare'}    = 2;
            $changes->{'spamd_config'}->{'maxchildren'} = 6;
        }
        elsif ( $mem_on_system < 4000 ) {
            $changes->{'spamd_config'}->{'maxspare'}    = 3;
            $changes->{'spamd_config'}->{'maxchildren'} = 9;
        }
        else {
            $changes->{'spamd_config'}->{'maxspare'}    = 3;
            $changes->{'spamd_config'}->{'maxchildren'} = 12;
        }
    }

    return $changes;
}

sub make_changes {
    my ( $self, $changes_hr ) = @_;

    if ( $changes_hr->{'conserve_memory'} ) {
        print '[*] Enabling conserve_memory options... ';
        Cpanel::FileUtils::TouchFile::touchfile('/var/cpanel/conserve_memory')
          if !$self->{'opts'}->{'dry-run'};
        print "Done\n";
    }
    elsif ( -e '/var/cpanel/conserve_memory' ) {
        print '[*] Disabling conserve_memory options... ';
        unlink '/var/cpanel/conserve_memory'
          if !$self->{'opts'}->{'dry-run'};
        print "Done\n";
    }

    require Cpanel::Config::Services;
    my $restarts = [qw/exim dovecot tailwatchd/];
    if ( Cpanel::Config::Services::service_enabled('spamd') ) {
        $self->update_spamd_config( $changes_hr->{'spamd_config'} );
        unshift @{$restarts}, 'spamd';
    }
    return $restarts;
}

sub update_spamd_config {
    my ( $self, $spamd_config ) = @_;
    my $ex;

    require Cpanel::Transaction::File::LoadConfig;
    try {
        my $cpspamd_txn      = Cpanel::Transaction::File::LoadConfig->new( 'path' => $CPSPAMD_PATH, 'delimiter' => '=', 'permissions' => 0644 );
        my $cur_spamd_config = $cpspamd_txn->get_data();
        foreach my $directive ( sort ( Cpanel::ArrayFunc::Uniq::uniq( keys %{$spamd_config}, keys %{$cur_spamd_config} ) ) ) {
            if ( !exists $cur_spamd_config->{$directive} ) {
                print "[*] Adding spamassassin $directive as “$spamd_config->{$directive}”...\n";
            }
            elsif ( !exists $spamd_config->{$directive} || $spamd_config->{$directive} == $cur_spamd_config->{$directive} ) {
                $spamd_config->{$directive} = $cur_spamd_config->{$directive};
                print "[*] Preserving spamassassin $directive as “$spamd_config->{$directive}”...\n";
            }
            else {
                print "[*] Switching spamassassin $directive from “$cur_spamd_config->{$directive}” to “$spamd_config->{$directive}”...\n";
            }
        }

        if ( !$self->{'opts'}->{'dry-run'} ) {
            $cpspamd_txn->set_data($spamd_config);
            $cpspamd_txn->save_or_die();
        }

        print "[+] Done\n";
    }
    catch {
        $ex = $_;

        print "[!] " . Cpanel::Exception::get_string_no_id($ex) . "\n";
    };

    return $ex ? 0 : 1;
}

sub _restart_services {
    my ( $self, $restarts_ar ) = @_;

    return if $self->{'opts'}->{'dry-run'};

    print "[*] Enqueueing service restarts....\n";
    foreach my $service ( @{$restarts_ar} ) {
        _schedule_cpservices_task("restartsrv $service");
    }
    print "[+] Done\n";
    return;
}

sub _mark_run_complete {
    my $self = shift;

    if ( !-e '/var/cpanel/vps_optimized' ) {
        mkdir( '/var/cpanel/vps_optimized', 0700 );
    }

    Cpanel::FileUtils::TouchFile::touchfile("/var/cpanel/vps_optimized/$version")
      if !$self->{'opts'}->{'dry-run'};

    print "[+] Optimizations Complete!\n";
    return 1;
}

sub _should_run_on_environment {
    my $self = shift;

    my $envtype = Cpanel::LoadFile::loadfile('/var/cpanel/envtype');
    if ( $envtype && $envtype eq 'standard' ) {
        print "[*] This script is not meant to be run on standard environments\n";
        return 0;
    }
    if ( -e '/var/cpanel/vps_optimized/' . $version && !$self->{'opts'}->{'force'} ) {
        print "[*] Optimizations have already been performed once. Use --force to redo optimizations\n";
        return 0;
    }
    return 1;
}

sub _schedule_cpservices_task {
    my ($task_str) = @_;

    my $err;
    require Cpanel::ServerTasks;
    try {
        Cpanel::ServerTasks::schedule_task( ['CpServicesTasks'], 5, $task_str );
    }
    catch {
        $err = $_;
    };
    if ($err) {
        print "[!] " . Cpanel::Exception::get_string_no_id($err) . "\n";
        return 0;
    }
    return 1;
}

sub _validate_environment {
    my $self = shift;

    if ( !-e '/usr/local/cpanel/cpkeyclt' ) {
        print "[!] Incomplete cPanel installation found. Missing cpkeyclt binary!\n" if $self->{'opts'}->{'verbose'};
        return 0;
    }

    if ( !-e '/var/cpanel/envtype' ) {
        print "[*] Validating system environment via cpkeyclt...\n" if $self->{'opts'}->{'verbose'};
        system '/usr/local/cpanel/cpkeyclt';
        if ( !-e '/var/cpanel/envtype' ) {
            print "[!] Problem verifying license information";
            return 0;
        }
    }

    return 1;
}

sub _parse_and_validate_opts {
    my $cmdline_args_ar = shift;

    my $opts = {};
    Getopt::Long::GetOptionsFromArray(
        $cmdline_args_ar,
        $opts,
        'help',    'verbose', 'force',
        'dry-run', 'skipstartup'
    ) or die Cpanel::Exception->create_raw("[!] Invalid usage. See --help\n")->to_string_no_id();

    return $opts;
}

1;

__END__

=encoding utf8

=head1 NAME

vps_optimizer

=head1 DESCRIPTION

Utility to optimize services for Virtual Private Servers.

=head1 SYNOPSIS

    vps_optimizer [OPTIONS]

    --dry-run         Do not perform any optimization. Simply print what will be done to the screen.
    --skipstartup     Do not [re]start services after configuration changes have been made.
    --force           Perform optimizations even if script was run previously.
    --verbose         Enable verbose output

    --help            This documentation.

=cut