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

# cpanel - scripts/check_mysql                     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::check_mysql;

use strict;
use warnings;

use Cpanel::Services::Enabled        ();
use Cpanel::ConfigFiles              ();
use Cpanel::Daemonizer::Tiny         ();
use Cpanel::FileUtils::Open          ();
use Cpanel::FindBin                  ();
use Cpanel::DB::Reserved             ();
use Cpanel::MysqlUtils::MyCnf::Basic ();
use Cpanel::MysqlUtils::Dir          ();
use Cpanel::Alarm                    ();
use Cpanel::Unix::PID::Tiny          ();
use Cpanel::Imports;

exit script(@ARGV) unless caller;

sub report_errors {
    my ($errors) = @_;

    require Cpanel::Notify;
    Cpanel::Notify::notification_class(
        'class'            => 'Check::MySQL',
        'application'      => 'Check::MySQL',
        'constructor_args' => [
            'origin' => 'check_mysql',
            'report' => $errors,
        ]
    );

    return;
}

sub run_mysqlcheck {
    my ( $mysqlcheck, $db ) = @_;

    my @output = `LANG=C $mysqlcheck -u root -m --silent --databases $db 2>&1`;
    return @output;
}

sub daemon_process {
    my ($uxpd) = @_;
    $uxpd->pid_file('/var/run/check_mysql.pid');    # update our pid file to new sporked PID

    # These are the databases we analyze
    my @databases = grep { !m/^pg_/ && !m/^postgres$/ && !m/^test$/ } Cpanel::DB::Reserved::get_reserved_database_names();

    my $timeout_seconds = 64800;                                                        # 64800 seconds == 18 hours
    my $mysqlcheck      = Cpanel::FindBin::findbin("mysqlcheck");
    my $mysqldir        = Cpanel::MysqlUtils::Dir::getmysqldir() || '/var/lib/mysql';
    my %errors;
    my %processed;
    my $ret = eval {

        # must go out of scope to stop and clean up, ick on a stick
        my $timeout = Cpanel::Alarm->new( $timeout_seconds, sub { die "time out\n" } );
        for my $db (@databases) {
            if ( $db ne 'mysql' && !-d "$mysqldir/$db" ) {    # if mysql is missing then @output contains an error
                $processed{$db} = 1;
                next;
            }

            logger->info("starting mysqlcheck on $db (PID $$)");
            my @output = run_mysqlcheck( $mysqlcheck, $db );
            if ( grep { /error: 2002: Can't connect/ } @output ) {
                logger->warn("mysqlcheck can't connect to MySQL");
                return 0;
            }
            logger->info("mysqlcheck of $db is finished (PID $$)");
            my $oops = purge_warnings( \@output );
            if ($oops) {
                logger->warn("mysqlcheck found errors on $db: $oops");
                $errors{$db} = $oops;
            }
            else {
                logger->info("mysqlcheck found no errors on $db");
            }
            $processed{$db} = 2;
        }
        return 1;
    };
    return if defined $ret && $ret == 0;

    for my $db (@databases) {
        next if exists $processed{$db};
        next if $db ne 'mysql' && !-d "$mysqldir/$db";    # in case the timeout happened right before $processed{$db} = 1; we just won a race!
        my $timeout_hours = $timeout_seconds / 60 / 60;
        $errors{$db} = "not checked because mysqlcheck has been running for $timeout_hours hours (large data? $mysqldir partition full?)";
    }

    if ( keys %errors ) {
        report_errors( \%errors );
    }

    return;
}

sub script {
    local $ENV{'HOME'} = '/root';

    die "/usr/local/cpanel/scripts/check_mysql is currently disabled.\n" if -e '/etc/check_mysql_disable';

    die "MySQL is disabled.\n" unless Cpanel::Services::Enabled::is_enabled('mysql');

    # This script is not written in a way so as to support remote mysql servers
    die "Remote MySQL database servers are not supported.\n" if Cpanel::MysqlUtils::MyCnf::Basic::is_remote_mysql();

    # this can be an expensive and thus time consuming thing so only allow one run at a time and give it a large timeout (via $timeout_seconds)
    my $uxpd = Cpanel::Unix::PID::Tiny->new();
    die "/usr/local/cpanel/scripts/check_mysql is currently running.\n" if !$uxpd->pid_file('/var/run/check_mysql.pid');

    my $pid = Cpanel::Daemonizer::Tiny::run_as_daemon(
        sub {
            Cpanel::FileUtils::Open::sysopen_with_real_perms( \*STDERR, $Cpanel::ConfigFiles::CPANEL_ROOT . '/logs/error_log', 'O_WRONLY|O_APPEND|O_CREAT', 0600 );
            open( STDOUT, '>&', \*STDERR ) || warn "Failed to redirect STDOUT to STDERR";
            daemon_process($uxpd);
        }
    );

    print locale->maketext( "“[_1]” will complete in the background (process ID [_2]).", 'check_mysql', $pid ) . "\n";

    return 0;
}

sub purge_warnings {
    my ($output_ar) = @_;

    my $full_output = '';

    # Loop through each line get rid of warnings
    my $previous_line = '';
    foreach my $line (@$output_ar) {
        chomp $line;

        # Skip the warnings and a non-Error-error: http://bugs.mysql.com/bug.php?id=30487
        if ( $line =~ /^([iI]nfo|[nN]ote|[wW]arning)/ || $line =~ m/Error\s*:\s*You can't use locks with log tables\./ ) {
            $previous_line = '';
            next;
        }

        # We only allow a line if it is not followed by a warning
        $full_output .= $previous_line . "\n" if $previous_line;
        $previous_line = $line;
    }

    $full_output .= $previous_line . "\n" if $previous_line;
    return $full_output;
}