Jyxo\Mail\Parser::parseMultiparts PHP Method

    private function parseMultiparts(string $pid, string $mimeType, string $lookFor = 'all', int $pidAdd = 1, bool $getAlternative = true)
    {
        // If the type is message/rfc822, gathers subparts that begin with the same Id
        // Skips multipart/alternative or multipart/report
        $excludeMime = $mimeType;
        $mimeType = 'text/plain' == $excludeMime ? 'text/html' : 'text/plain';
        $partLevel = count(explode('.', $pid));
        $pidLength = strlen($pid);
        foreach ($this->structure['pid'] as $partNo => $id) {
            $level = count(explode('.', $this->structure['pid'][$partNo]));
            switch ($lookFor) {
                case 'all':
                    $condition = true;
                    break;
                case 'subparts':
                    $condition = $level == $partLevel + 1 && $pid == substr($this->structure['pid'][$partNo], 0, $pidLength);
                    break;
                case 'top':
                    // Break missing intentionally
                // Break missing intentionally
                default:
                    if ($this->isMultipart('related') || $this->isMultipart('mixed')) {
                        // Top level and second level, but the same parent
                        $condition = false === strpos($this->structure['pid'][$partNo], '.') || 2 == $level && substr($this->defaultPid, 0, 1) == substr($this->structure['pid'][$partNo], 0, 1);
                    } else {
                        // Top level
                        $condition = false === strpos($this->structure['pid'][$partNo], '.');
                    }
                    break;
            }
            if ($condition) {
                if ($this->isPartMultipart($partNo, 'alternative') || $this->isPartMultipart($partNo, 'report') || $this->isPartMultipart($partNo, 'mixed')) {
                    $subLevel = count(explode('.', $this->structure['pid'][$partNo]));
                    foreach ($this->structure['pid'] as $multipartNo => $multipartPid) {
                        // Part must begin with the last tested Id and be in the next level
                        if ($this->structure['ftype'][$multipartNo] == $mimeType && $getAlternative && $subLevel == $partLevel + $pidAdd && $pid == substr($multipartPid, 0, strlen($this->structure['pid'][$partNo]))) {
                            $this->addPart($partNo, 'inline');
                            break;
                        }
                    }
                } elseif ('inline' == $this->structure['disposition'][$partNo] && !$this->isPartMultipart($partNo, 'related') && !$this->isPartMultipart($partNo, 'mixed')) {
                    // It is inline, but not related or mixed type
                    if ($this->structure['ftype'][$partNo] != $excludeMime && $pid != $this->structure['pid'][$partNo] && ($getAlternative || !$this->isParentAlternative($partNo)) || $this->structure['ftype'][$partNo] == $excludeMime && isset($this->structure['fname'][$partNo]) && $pid != $this->structure['pid'][$partNo]) {
                        $this->addPart($partNo, 'inline');
                    }
                } elseif ('attachment' == $this->structure['disposition'][$partNo]) {
                    // It is an attachment; add to the attachment list
                    $this->addPart($partNo, 'attach');
                }
            }
        }
    }