curSheet = -1;
        $this->defaultFont = 'Calibri';
        $this->sheets = [['name' => 'Sheet1', 'rows' => [], 'hyperlinks' => [], 'mergecells' => [], 'colwidth' => [], 'autofilter' => '']];
        $this->extLinkId = 0;
        $this->SI = [];        // sharedStrings index
        $this->SI_KEYS = []; //  & keys
        // https://c-rex.net/projects/samples/ooxml/e1/Part4/OOXML_P4_DOCX_numFmts_topic_ID0E6KK6.html
        $this->NF = [
            self::N_RUB => '#,##0.00\ "₽"',
            self::N_DOLLAR => '[$$-1]#,##0.00',
            self::N_EURO => '#,##0.00\ [$€-1]'
        ];
        $this->NF_KEYS = array_flip($this->NF);
        $this->BR_STYLE = [
            self::B_NONE => 'none',
            self::B_THIN => 'thin',
            self::B_MEDIUM => 'medium',
            self::B_DASHED => 'dashed',
            self::B_DOTTED => 'dotted',
            self::B_THICK => 'thick',
            self::B_DOUBLE => 'double',
            self::B_HAIR => 'hair',
            self::B_MEDIUM_DASHED => 'mediumDashed',
            self::B_DASH_DOT => 'dashDot',
            self::B_MEDIUM_DASH_DOT => 'mediumDashDot',
            self::B_DASH_DOT_DOT => 'dashDotDot',
            self::B_MEDIUM_DASH_DOT_DOT => 'mediumDashDotDot',
            self::B_SLANT_DASH_DOT => 'slantDashDot'
        ];
        $this->XF = [  // styles 0 - num fmt, 1 - align, 2 - font, 3 - fill, 4 - font color, 5 - bgcolor, 6 - border
            [self::N_NORMAL, self::A_DEFAULT, self::F_NORMAL, self::FL_NONE, 0, 0, ''],
            [self::N_NORMAL, self::A_DEFAULT, self::F_NORMAL, self::FL_GRAY_125, 0, 0, ''], // hack
        ];
        $this->XF_KEYS[implode('-', $this->XF[0])] = 0; // & keys
        $this->XF_KEYS[implode('-', $this->XF[1])] = 1;
        $this->template = [
            '_rels/.rels' => '
',
            'docProps/app.xml' => '
0
' . __CLASS__ . '',
            'docProps/core.xml' => '
{DATE}
en-US
{DATE}
1
',
            'xl/_rels/workbook.xml.rels' => '
{SHEETS}',
            'xl/worksheets/sheet1.xml' => '
{COLS}{ROWS}{AUTOFILTER}{MERGECELLS}{HYPERLINKS}',
            'xl/worksheets/_rels/sheet1.xml.rels' => '
{HYPERLINKS}',
            'xl/sharedStrings.xml' => '
{STRINGS}',
            'xl/styles.xml' => '
{NUMFMTS}
{FONTS}
{FILLS}
{BORDERS}
{XF}
    
',
            'xl/workbook.xml' => '
{SHEETS}
',
            '[Content_Types].xml' => '
{TYPES}
',
        ];
        // 
        // 0100
1200
        // Простой шаблонБудем делать генератор
    }
    public static function fromArray(array $rows, $sheetName = null)
    {
        return (new static())->addSheet($rows, $sheetName);
    }
    public function addSheet(array $rows, $name = null)
    {
        $this->curSheet++;
        if ($name === null) { // autogenerated sheet names
            $name = 'Sheet' . ($this->curSheet + 1);
        } else {
            $name = mb_substr($name, 0, 31);
            $names = [];
            foreach ($this->sheets as $sh) {
                $names[mb_strtoupper($sh['name'])] = 1;
            }
            for ($i = 0; $i < 100; $i++) {
                $postfix = ' (' . $i . ')';
                $new_name = ($i === 0) ? $name : $name . $postfix;
                if (mb_strlen($new_name) > 31) {
                    $new_name = mb_substr($name, 0, 31 - mb_strlen($postfix)) . $postfix;
                }
                $NEW_NAME = mb_strtoupper($new_name);
                if (!isset($names[$NEW_NAME])) {
                    $name = $new_name;
                    break;
                }
            }
        }
        $this->sheets[$this->curSheet] = ['name' => $name, 'hyperlinks' => [], 'mergecells' => [], 'colwidth' => [], 'autofilter' => ''];
        if (isset($rows[0]) && is_array($rows[0])) {
            $this->sheets[$this->curSheet]['rows'] = $rows;
        } else {
            $this->sheets[$this->curSheet]['rows'] = [];
        }
        return $this;
    }
    public function __toString()
    {
        $fh = fopen('php://memory', 'wb');
        if (!$fh) {
            return '';
        }
        if (!$this->_write($fh)) {
            fclose($fh);
            return '';
        }
        $size = ftell($fh);
        fseek($fh, 0);
        return (string)fread($fh, $size);
    }
    public function saveAs($filename)
    {
        $fh = fopen($filename, 'wb');
        if (!$fh) {
            return false;
        }
        if (!$this->_write($fh)) {
            fclose($fh);
            return false;
        }
        fclose($fh);
        return true;
    }
    public function download()
    {
        return $this->downloadAs(gmdate('YmdHi') . '.xlsx');
    }
    public function downloadAs($filename)
    {
        $fh = fopen('php://memory', 'wb');
        if (!$fh) {
            return false;
        }
        if (!$this->_write($fh)) {
            fclose($fh);
            return false;
        }
        $size = ftell($fh);
        header('Content-type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
        header('Content-Disposition: attachment; filename="' . $filename . '"');
        header('Last-Modified: ' . gmdate('D, d M Y H:i:s \G\M\T', time()));
        header('Content-Length: ' . $size);
        while (ob_get_level()) {
            ob_end_clean();
        }
        fseek($fh, 0);
        fpassthru($fh);
        fclose($fh);
        return true;
    }
    protected function _write($fh)
    {
        $dirSignatureE = "\x50\x4b\x05\x06"; // end of central dir signature
        $zipComments = 'Generated by ' . __CLASS__ . ' PHP class, thanks sergey.shuchkin@gmail.com';
        if (!$fh) {
            return false;
        }
        $cdrec = '';    // central directory content
        $entries = 0;    // number of zipped files
        $cnt_sheets = count($this->sheets);
        foreach ($this->template as $cfilename => $template) {
            if ($cfilename === 'xl/_rels/workbook.xml.rels') {
                $s = '';
                for ($i = 0; $i < $cnt_sheets; $i++) {
                    $s .= '\n";
                }
                $s .= '';
                $template = str_replace('{SHEETS}', $s, $template);
                $this->_writeEntry($fh, $cdrec, $cfilename, $template);
                $entries++;
            } elseif ($cfilename === 'xl/workbook.xml') {
                $s = '';
                foreach ($this->sheets as $k => $v) {
                    $s .= '';
                }
                $template = str_replace('{SHEETS}', $s, $template);
                $this->_writeEntry($fh, $cdrec, $cfilename, $template);
                $entries++;
            } elseif ($cfilename === 'docProps/core.xml') {
                $template = str_replace('{DATE}', gmdate('Y-m-d\TH:i:s\Z'), $template);
                $this->_writeEntry($fh, $cdrec, $cfilename, $template);
                $entries++;
            } elseif ($cfilename === 'xl/sharedStrings.xml') {
                if (!count($this->SI)) {
                    $this->SI[] = 'No Data';
                }
                $si_cnt = count($this->SI);
                $si = '' . implode("\r\n", $this->SI) . '';
                $template = str_replace(['{CNT}', '{STRINGS}'], [$si_cnt, $si], $template);
                $this->_writeEntry($fh, $cdrec, $cfilename, $template);
                $entries++;
            } elseif ($cfilename === 'xl/worksheets/sheet1.xml') {
                foreach ($this->sheets as $k => $v) {
                    $filename = 'xl/worksheets/sheet' . ($k + 1) . '.xml';
                    $xml = $this->_sheetToXML($k, $template);
                    $this->_writeEntry($fh, $cdrec, $filename, $xml);
                    $entries++;
                }
                $xml = null;
            } elseif ($cfilename === 'xl/worksheets/_rels/sheet1.xml.rels') {
                foreach ($this->sheets as $k => $v) {
                    if ($this->extLinkId) {
                        $RH = [];
                        $filename = 'xl/worksheets/_rels/sheet' . ($k + 1) . '.xml.rels';
                        foreach ($v['hyperlinks'] as $h) {
                            if ($h['ID']) {
                                $RH[] = '';
                            }
                        }
                        $xml = str_replace('{HYPERLINKS}', implode("\r\n", $RH), $template);
                        $this->_writeEntry($fh, $cdrec, $filename, $xml);
                        $entries++;
                    }
                }
                $xml = null;
            } elseif ($cfilename === '[Content_Types].xml') {
                $TYPES = [''];
                foreach ($this->sheets as $k => $v) {
                    $TYPES[] = '';
                    if ($this->extLinkId) {
                        $TYPES[] = '';
                    }
                }
                $template = str_replace('{TYPES}', implode("\r\n", $TYPES), $template);
                $this->_writeEntry($fh, $cdrec, $cfilename, $template);
                $entries++;
            } elseif ($cfilename === 'xl/styles.xml') {
                $NF = $XF = $FONTS = $F_KEYS = $FILLS = $FL_KEYS = [];
                $BR = [''];
                $BR_KEYS = [0 => 0];
                foreach ($this->NF as $k => $v) {
                    $NF[] = '';
                }
                foreach ($this->XF as $xf) {
                    // 0 - num fmt, 1 - align, 2 - font, 3 - fill, 4 - font color, 5 - bgcolor, 6 - border
                    // fonts
                    $F_KEY = $xf[2] . '-' . $xf[4];
                    if (isset($F_KEYS[$F_KEY])) {
                        $F_ID = $F_KEYS[$F_KEY];
                    } else {
                        $F_ID = $F_KEYS[$F_KEY] = count($FONTS);
                        $FONTS[] = ''
                            . ($this->defaultFontSize ? '' : '')
                            . ($xf[2] & self::F_BOLD ? '' : '')
                            . ($xf[2] & self::F_ITALIC ? '' : '')
                            . ($xf[2] & self::F_UNDERLINE ? '' : '')
                            . ($xf[2] & self::F_STRIKE ? '' : '')
                            . ($xf[2] & self::F_HYPERLINK ? '' : '')
                            . ($xf[2] & self::F_COLOR ? '' : '')
                            . '';
                    }
                    // fills
                    $FL_KEY = $xf[3] . '-' . $xf[5];
                    if (isset($FL_KEYS[$FL_KEY])) {
                        $FL_ID = $FL_KEYS[$FL_KEY];
                    } else {
                        $FL_ID = $FL_KEYS[$FL_KEY] = count($FILLS);
                        $FILLS[] = '' : ' />')
                            . '';
                    }
                    $align = ($xf[1] & self::A_LEFT ? ' horizontal="left"' : '')
                        . ($xf[1] & self::A_RIGHT ? ' horizontal="right"' : '')
                        . ($xf[1] & self::A_CENTER ? ' horizontal="center"' : '')
                        . ($xf[1] & self::A_TOP ? ' vertical="top"' : '')
                        . ($xf[1] & self::A_MIDDLE ? ' vertical="center"' : '')
                        . ($xf[1] & self::A_BOTTOM ? ' vertical="bottom"' : '')
                        . ($xf[1] & self::A_WRAPTEXT ? ' wrapText="1"' : '');
                    // border
                    $BR_ID = 0;
                    if ($xf[6] !== '') {
                        $b = $xf[6];
                        if (isset($BR_KEYS[$b])) {
                            $BR_ID = $BR_KEYS[$b];
                        } else {
                            $BR_ID = count($BR_KEYS);
                            $BR_KEYS[$b] = $BR_ID;
                            $border = '';
                            $ba = explode(' ', $b);
                            if (!isset($ba[1])) {
                                $ba[] = $ba[0];
                                $ba[] = $ba[0];
                                $ba[] = $ba[0];
                            }
                            if (!isset($ba[4])) { // diagonal
                                $ba[] = 'none';
                            }
                            $sides = [ 'left' => 3, 'right' => 1, 'top' => 0, 'bottom' => 2, 'diagonal' => 4];
                            foreach ($sides as $side => $idx) {
                                $s = 'thin';
                                $c = '';
                                $va = explode('#', $ba[$idx]);
                                if (isset($va[1])) {
                                    $s = $va[0] === '' ? 'thin' : $va[0];
                                    $c = $va[1];
                                } elseif (in_array($va[0], $this->BR_STYLE, true)) {
                                    $s = $va[0];
                                } else {
                                    $c = $va[0];
                                }
                                if (strlen($c) === 6) {
                                    $c = 'FF' . $c;
                                }
                                if ($s && $s !== 'none') {
                                    $border .= '<' . $side . ' style="' . $s . '">'
                                        . ''
                                        . '' . $side . '>';
                                } else {
                                    $border .= '<' . $side . '/>';
                                }
                            }
                            $border .= '';
                            $BR[] = $border;
                        }
                    }
                    $XF[] = ' 0 ? ' applyNumberFormat="1"' : '')
                        . ($F_ID > 0 ? ' applyFont="1"' : '')
                        . ($FL_ID > 0 ? ' applyFill="1"' : '')
                        . ($BR_ID > 0 ? ' applyBorder="1"' : '')
                        . ($align ? ' applyAlignment="1">' : '/>');
                }
                // wrap collections
                array_unshift($NF, '');
                $NF[] = '';
                array_unshift($XF, '');
                $XF[] = '';
                array_unshift($FONTS, '');
                $FONTS[] = '';
                array_unshift($FILLS, '');
                $FILLS[] = '';
                array_unshift($BR, '');
                $BR[] = '';
                $template = str_replace(
                    ['{NUMFMTS}', '{FONTS}', '{XF}', '{FILLS}', '{BORDERS}'],
                    [implode("\r\n", $NF), implode("\r\n", $FONTS), implode("\r\n", $XF), implode("\r\n", $FILLS), implode("\r\n", $BR)],
                    $template);
                $this->_writeEntry($fh, $cdrec, $cfilename, $template);
                $entries++;
            } else {
                $this->_writeEntry($fh, $cdrec, $cfilename, $template);
                $entries++;
            }
        }
        $before_cd = ftell($fh);
        fwrite($fh, $cdrec);
        // end of central dir
        fwrite($fh, $dirSignatureE);
        fwrite($fh, pack('v', 0)); // number of this disk
        fwrite($fh, pack('v', 0)); // number of the disk with the start of the central directory
        fwrite($fh, pack('v', $entries)); // total # of entries "on this disk"
        fwrite($fh, pack('v', $entries)); // total # of entries overall
        fwrite($fh, pack('V', mb_strlen($cdrec, '8bit')));     // size of central dir
        fwrite($fh, pack('V', $before_cd));         // offset to start of central dir
        fwrite($fh, pack('v', mb_strlen($zipComments, '8bit'))); // .zip file comment length
        fwrite($fh, $zipComments);
        return true;
    }
    protected function _writeEntry($fh, &$cdrec, $cfilename, $data)
    {
        $zipSignature = "\x50\x4b\x03\x04"; // local file header signature
        $dirSignature = "\x50\x4b\x01\x02"; // central dir header signature
        $e = [];
        $e['uncsize'] = mb_strlen($data, '8bit');
        // if data to compress is too small, just store it
        if ($e['uncsize'] < 256) {
            $e['comsize'] = $e['uncsize'];
            $e['vneeded'] = 10;
            $e['cmethod'] = 0;
            $zdata = $data;
        } else { // otherwise, compress it
            $zdata = gzcompress($data);
            $zdata = substr(substr($zdata, 0, -4), 2); // fix crc bug (thanks to Eric Mueller)
            $e['comsize'] = mb_strlen($zdata, '8bit');
            $e['vneeded'] = 10;
            $e['cmethod'] = 8;
        }
        $e['bitflag'] = 0;
        $e['crc_32'] = crc32($data);
        // Convert date and time to DOS Format, and set then
        $lastmod_timeS = str_pad(decbin(date('s') >= 32 ? date('s') - 32 : date('s')), 5, '0', STR_PAD_LEFT);
        $lastmod_timeM = str_pad(decbin(date('i')), 6, '0', STR_PAD_LEFT);
        $lastmod_timeH = str_pad(decbin(date('H')), 5, '0', STR_PAD_LEFT);
        $lastmod_dateD = str_pad(decbin(date('d')), 5, '0', STR_PAD_LEFT);
        $lastmod_dateM = str_pad(decbin(date('m')), 4, '0', STR_PAD_LEFT);
        $lastmod_dateY = str_pad(decbin(date('Y') - 1980), 7, '0', STR_PAD_LEFT);
        # echo "ModTime: $lastmod_timeS-$lastmod_timeM-$lastmod_timeH (".date("s H H").")\n";
        # echo "ModDate: $lastmod_dateD-$lastmod_dateM-$lastmod_dateY (".date("d m Y").")\n";
        $e['modtime'] = bindec("$lastmod_timeH$lastmod_timeM$lastmod_timeS");
        $e['moddate'] = bindec("$lastmod_dateY$lastmod_dateM$lastmod_dateD");
        $e['offset'] = ftell($fh);
        fwrite($fh, $zipSignature);
        fwrite($fh, pack('s', $e['vneeded'])); // version_needed
        fwrite($fh, pack('s', $e['bitflag'])); // general_bit_flag
        fwrite($fh, pack('s', $e['cmethod'])); // compression_method
        fwrite($fh, pack('s', $e['modtime'])); // lastmod_time
        fwrite($fh, pack('s', $e['moddate'])); // lastmod_date
        fwrite($fh, pack('V', $e['crc_32']));  // crc-32
        fwrite($fh, pack('I', $e['comsize'])); // compressed_size
        fwrite($fh, pack('I', $e['uncsize'])); // uncompressed_size
        fwrite($fh, pack('s', mb_strlen($cfilename, '8bit')));   // file_name_length
        fwrite($fh, pack('s', 0));  // extra_field_length
        fwrite($fh, $cfilename);    // file_name
        // ignoring extra_field
        fwrite($fh, $zdata);
        // Append it to central dir
        $e['external_attributes'] = (substr($cfilename, -1) === '/' && !$zdata) ? 16 : 32; // Directory or file name
        $e['comments'] = '';
        $cdrec .= $dirSignature;
        $cdrec .= "\x0\x0";                  // version made by
        $cdrec .= pack('v', $e['vneeded']); // version needed to extract
        $cdrec .= "\x0\x0";                  // general bit flag
        $cdrec .= pack('v', $e['cmethod']); // compression method
        $cdrec .= pack('v', $e['modtime']); // lastmod time
        $cdrec .= pack('v', $e['moddate']); // lastmod date
        $cdrec .= pack('V', $e['crc_32']);  // crc32
        $cdrec .= pack('V', $e['comsize']); // compressed filesize
        $cdrec .= pack('V', $e['uncsize']); // uncompressed filesize
        $cdrec .= pack('v', mb_strlen($cfilename, '8bit')); // file name length
        $cdrec .= pack('v', 0);                // extra field length
        $cdrec .= pack('v', mb_strlen($e['comments'], '8bit')); // file comment length
        $cdrec .= pack('v', 0); // disk number start
        $cdrec .= pack('v', 0); // internal file attributes
        $cdrec .= pack('V', $e['external_attributes']); // internal file attributes
        $cdrec .= pack('V', $e['offset']); // relative offset of local header
        $cdrec .= $cfilename;
        $cdrec .= $e['comments'];
    }
    protected function _sheetToXML($idx, $template)
    {
        // locale floats fr_FR 1.234,56 -> 1234.56
        $_loc = setlocale(LC_NUMERIC, 0);
        setlocale(LC_NUMERIC, 'C');
        $COLS = [];
        $ROWS = [];
        if (count($this->sheets[$idx]['rows'])) {
            $COLS[] = '';
            $CUR_ROW = 0;
            $COL = [];
            foreach ($this->sheets[$idx]['rows'] as $r) {
                $CUR_ROW++;
                $row = '';
                $CUR_COL = 0;
                $RH = 0; // row height
                foreach ($r as $v) {
                    $CUR_COL++;
                    if (!isset($COL[$CUR_COL])) {
                        $COL[$CUR_COL] = 0;
                    }
                    $cname = $this->num2name($CUR_COL) . $CUR_ROW;
                    if ($v === null || $v === '') {
                        $row .= '';
                        continue;
                    }
                    $ct = $cv = $cf = null;
                    $N = $A = $F = $FL = $C = $BG = 0;
                    $BR = '';
                    if (is_string($v)) {
                        if ($v[0] === "\0") { // RAW value as string
                            $v = substr($v, 1);
                            $vl = mb_strlen($v);
                        } else {
                            if (strpos($v, '<') !== false) { // tags?
                                if (strpos($v, '') !== false) {
                                    $F += self::F_BOLD;
                                }
                                if (strpos($v, '') !== false) {
                                    $F += self::F_ITALIC;
                                }
                                if (strpos($v, '') !== false) {
                                    $F += self::F_UNDERLINE;
                                }
                                if (strpos($v, '') !== false) {
                                    $F += self::F_STRIKE;
                                }
                                if (preg_match('/