<?php
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
use PhpOffice\PhpSpreadsheet\IOFactory;
use PhpOffice\PhpSpreadsheet\Reader\Exception as SpreadsheetReaderException;
use PhpOffice\PhpSpreadsheet\Cell\Coordinate;
use PhpOffice\PhpSpreadsheet\Style\Alignment;
use PhpOffice\PhpSpreadsheet\Style\Color;
use PhpOffice\PhpSpreadsheet\Style\Font;
use PhpOffice\PhpSpreadsheet\Style\Fill;
use PhpOffice\PhpSpreadsheet\Style\Border;
use PhpOffice\PhpSpreadsheet\Style\Borders;


if (!function_exists('generate_excel')) {
    
    function generate_excel($headlines, $xldata)
    {

        $headersMain = $headlines['header1'];
        $headersSub = $headlines['header2'];
        $company = $headlines['company_name'];
        $filename = $headlines['file_name'];
        $type = $headlines['type'];
        $footer = false;
        $mergeEndCol = $headlines['merge_end_column'];
        // $type = 1 means $data is single 
        // $type = 2 means $data is multiple array 
        

        // Create new Spreadsheet object
        $spreadsheet = new Spreadsheet();
        $sheet = $spreadsheet->getActiveSheet();
        
        // Set worksheet title 
        $sheet->setTitle('Sheet 1');

        
            // A1 Start here... should be compnay name .... 
                $sheet->setCellValue('A1', $company);

                // Get last column letter based on headers count
                // $lastColumnLetter = getExcelColumnName(count($headers) - 1);
                $colCount = count($headersMain);
    
                // Calculate end column by character math (works up to 'ZZ')
                $lastColumnLetter = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex($colCount);

                $sheet->mergeCells("A1:{$lastColumnLetter}1");

                // Style A1
                $sheet->getStyle("A1")->getFill()
                    ->setFillType(Fill::FILL_SOLID)
                    ->getStartColor()->setRGB('ADD8E6'); // Light blue

                $sheet->getStyle("A1")->getAlignment()
                    ->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER)
                    ->setVertical(\PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER);

                $sheet->getStyle("A1")->getFont()->setBold(true)->setSize(14);

                $sheet->getStyle("A1")->getFont()
                    ->getColor()
                    ->setRGB(Color::COLOR_WHITE);

            // /. A1 ends here 
            $currentRow = 2; // Start at row 2
            if($type == 1){
                $startCell = 'A' . $currentRow;
                $lastcolrow = callHeader($sheet, $headersMain, $startCell,$headersSub);
                $lastcolrow2 = callSkipRow($lastcolrow);
                $lastcolrow3 = callData($sheet,$headersMain,$xldata,$lastcolrow2,$mergeEndCol);    
                $lastcolrow4 = callSkipRow($lastcolrow3);
                if($footer){
                    $lastcolrow5 = callFooter($sheet, $headersMain, $xldata, $lastcolrow4,'','',$mergeEndCol);
                }
                

            }else if($type == 2){
                // $final_Footer=[];
                // foreach($xldata as $i => $xl){
                //     echo $i;
                //     echo "<pre>";
                //     print_r($xl[$i]);
                //     echo "</pre>";
                //     // echo count($xl[$i])."**";
                //     // $forFinalFooter 
                // }
                // foreach ($xldata as $i => $xl) {
                //     $forFinalFooter[] = $xl[$i];
                // }
                $final_Footer = isset($headlines['final_Footer']) && !empty($headlines['final_Footer']) ? $headlines['final_Footer'] : [];
                
                foreach ($xldata as $index => $data) {
                    if (!empty($data)) {
                        $startCell = 'A' . $currentRow;
                
                        $lastcolrow = callHeader($sheet, $headersMain, $startCell,$headersSub);
                        $lastcolrow2 = callSkipRow($lastcolrow);
                        $lastcolrow3 = callData($sheet, $headersMain, $data, $lastcolrow2);
                        $lastcolrow4 = callSkipRow($lastcolrow3);
                        $lastcolrow5 = callFooter($sheet, $headersMain, $data, $lastcolrow4,'Total Amount Rs','228B22',$mergeEndCol);
                        $lastcolrow6 = callSkipRow($lastcolrow5);
                
                        // Update currentRow for next iteration
                        $currentRow = (int) filter_var($lastcolrow6, FILTER_SANITIZE_NUMBER_INT);
                    } else {
                        $startCell = 'A' . $currentRow;
                        $lastcolrow = callHeader($sheet, $headersMain, $startCell,$headersSub);
                        $lastcolrow2 = callSkipRow($lastcolrow);
                
                        $currentRow = (int) filter_var($lastcolrow2, FILTER_SANITIZE_NUMBER_INT);
                    }
                }     

                if(!empty($final_Footer)){
                    $startCell = 'A' . $currentRow;
                    callFooter($sheet, $headersMain, $final_Footer[0], $startCell,'Final Net Salary Amount Rs','DC143C',$mergeEndCol);
                    // echo "cr".$currentRow;die;
                }
                
                // $final_Footer
                
            }

        // Create Excel writer
        $writer = new Xlsx($spreadsheet);
        $columnCount = count($headersMain);
        for ($col = 1; $col <= $columnCount; $col++) {
            $columnLetter = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex($col);
            $sheet->getColumnDimension($columnLetter)->setAutoSize(true);
        }

        $highestColumn = $sheet->getHighestColumn(); // e.g., 'E'
        $highestRow = $sheet->getHighestRow();       // e.g., 10

        // Build the full range (e.g., 'A1:E10')
        $range = 'A1:' . $highestColumn . $highestRow;

        // Apply border to that range
        $sheet->getStyle($range)->applyFromArray([
            'borders' => [
                'allBorders' => [
                    'borderStyle' => Border::BORDER_THIN,
                    'color' => ['argb' => 'FF000000'],
                ],
            ],
        ]);

        try {
            
            // Save Excel file to the specified path
            ob_clean();
            header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
            header("Content-Disposition: attachment; filename=\"$filename\"");
            header('Cache-Control: max-age=0');

            $writer->save('php://output'); // stream to browser
            exit; // Return true if file was successfully saved

        } catch (\Exception $e) {
            // Log or handle the exception
            return false; // Return false if there was an error saving the file
        }
    }
}


function callHeader($sheet, $headersMain, $startCell, $headersSub = []) {
    $rowNumber = (int) filter_var($startCell, FILTER_SANITIZE_NUMBER_INT);
    
    $startCol = 'A';
    $colCount = count($headersMain);
    
    // Calculate end column by character math (works up to 'ZZ')
    $endCol = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex($colCount);

    // Check if sub-header has any non-empty value
    $hasSubHeader = !empty(array_filter($headersSub, function ($val) {
        return trim($val) !== '';
    }));

    // 1. Write Main Header
    $sheet->fromArray([$headersMain], null, $startCell);
    $mainHeaderRange = "{$startCol}{$rowNumber}:{$endCol}{$rowNumber}";

    // Style Main Header
    $sheet->getStyle($mainHeaderRange)->applyFromArray([
        'font' => [
            'bold' => true,
            'color' => ['rgb' => 'FF0000'],
            'size' => 12,
        ],
        'alignment' => [
            'horizontal' => \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER,
            'vertical' => \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER,
        ]
    ]);

    if ($hasSubHeader) {
        // 2. Write Sub Header
        $subHeaderRow = $rowNumber + 1;
        $sheet->fromArray([$headersSub], null, "A{$subHeaderRow}");

        $subHeaderRange = "{$startCol}{$subHeaderRow}:{$endCol}{$subHeaderRow}";

        
            $sheet->getStyle($subHeaderRange)->applyFromArray([
                'font' => [
                    'bold' => true,
                    'color' => ['rgb' => 'FF0000'],
                    'size' => 12,
                ],
                'alignment' => [
                    'horizontal' => \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER,
                    'vertical' => \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER,
                ]
            ]);

        return 'A' . ($subHeaderRow + 1);
    } else {
        return 'A' . ($rowNumber + 1);
    }
}


function callData($sheet, $headers, $data, $startCell) {
    
    $startRow = (int) filter_var($startCell, FILTER_SANITIZE_NUMBER_INT);
    $startCol = 'A';
    $sheet->fromArray($data, null, $startCell);

    $dataRowCount = count($data);
    $lastDataRow = $startRow + $dataRowCount;

    // $dataColCount = count($headers);
    // $lastDataColumn = getExcelColumnName($dataColCount - 1);
    // $dataRange = "{$startCol}{$startRow}:{$lastDataColumn}{$lastDataRow}";
    // Set font color to black
    // $sheet->getStyle($dataRange)->getFont()->getColor()->setRGB('000000');

    return 'A' . ($lastDataRow + 1); // return next row
}

function callSkipRow($startCell){
    $row = (int) filter_var($startCell, FILTER_SANITIZE_NUMBER_INT);
    return 'A' . ($row + 1); // just skip a line
}

// function callFooter($sheet, $headers, $data, $startCell,$mergeEndindex) {
    
//     $row = (int) filter_var($startCell, FILTER_SANITIZE_NUMBER_INT);
    
//     $startCol = preg_replace('/[0-9]/', '', $startCell);
    
//     // Determine numeric columns dynamically
//     // $numericIndexes = [];
//     // foreach ($data as $index => $val) {
//     //     foreach ($data as $rowData) {
//     //         if (isset($rowData[$index]) && is_numeric($rowData[$index])) {
//     //             $numericIndexes[] = $index;
//     //             break;
//     //         }
//     //     }
//     // }
//     if (!empty($data)) {
//         // Look at the first row
//         $firstRow = $data[0];
    
//         foreach ($firstRow as $key => $value) {
//             foreach ($data as $row) {
//                 if (isset($row[$key]) && is_numeric($row[$key])) {
//                     $numericIndexes[] = $key; // use the key (could be column name)
//                     break;
//                 }
//             }
//         }
//     }
    
//     // Get first numeric column index for placing totals
//     if (empty($numericIndexes)) return 'A' . ($row + 1); // Nothing to total

//     sort($numericIndexes);
//     $firstNumericIndex = $numericIndexes[0];
//     $colCount = count($headers);
    
//     // Calculate end column by character math (works up to 'ZZ')
//     if($mergeEndindex == ''){
//         $mergeEndCol = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex($colCount - 1);
        
//     }else{
//         $mergeEndCol = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex((int)$mergeEndindex);
//     }
    

//         // echo gettype($row);die;

//     // Merge from A to column before first numeric column (for "TOTAL" label)
//     $sheet->mergeCells("A{$row}:{$mergeEndCol}{$row}");
//     $sheet->setCellValue("A{$row}", 'TOTAL');

//     // Style for TOTAL label
//     $sheet->getStyle("A{$row}:{$mergeEndCol}{$row}")->applyFromArray([
//         'font' => [
//             'bold' => true,
//             'size' => 14,
//             'color' => ['rgb' => '228B22']
//         ],
//         'alignment' => [
//             'horizontal' => \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER,
//             'vertical' => \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER
//         ]
//     ]);

//     // Total each numeric column and write to corresponding cell
//     foreach ($numericIndexes as $index) {
//         $total = 0;
//         foreach ($data as $rowData) {
//             $value = $rowData[$index] ?? 0;
//             if (is_numeric($value)) {
//                 $total += $value;
//             }
//         }
//         $colLetter = \PhpOffice\PhpSpreadsheet\Cell\Coordinate::stringFromColumnIndex((int)$index);
//         $sheet->setCellValue("{$colLetter}{$row}", $total);
//     }

//     return 'A' . ($row + 1); // Return next available row
// }
function callFooter($sheet, $headers, $data, $startCell,$label,$code,$mergeEndIndex = null) {
    $row = (int) filter_var($startCell, FILTER_SANITIZE_NUMBER_INT);
    $startCol = preg_replace('/[0-9]/', '', $startCell);

    $numericKeys = [];
    $columnKeys = array_keys($data[0] ?? []);
    $columnKeyToIndex = array_flip($columnKeys); // key => index

    // Detect numeric columns
    foreach ($columnKeys as $key) {
        foreach ($data as $rowData) {
            if (isset($rowData[$key]) && is_numeric($rowData[$key])) {
                $numericKeys[] = $key;
                break;
            }
        }
    }

    // If no numeric columns, skip total row
    if (empty($numericKeys)) {
        return $startCol . ($row + 1);
    }

    // Determine where to end the merge for the TOTAL label
    if ($mergeEndIndex === null || $mergeEndIndex === '') {
        $firstNumericKey = $numericKeys[0];
        $firstNumericIndex = $columnKeyToIndex[$firstNumericKey];
        $mergeEndIndex = $firstNumericIndex > 0 ? $firstNumericIndex - 1 : 0;
    }

    // Write totals for each numeric column
    foreach ($numericKeys as $colKey) {
        $total = 0;
        foreach ($data as $rowData) {
            $val = $rowData[$colKey] ?? 0;
            if (is_numeric($val)) {
                $total += $val;
            }
        }

        $colIndex = $columnKeyToIndex[$colKey];
        $colLetter = Coordinate::stringFromColumnIndex($colIndex + 1);
        $sheet->setCellValue("{$colLetter}{$row}", $total);
        $sheet->getStyle("{$colLetter}{$row}")->getNumberFormat()->setFormatCode('#,##0.00');
        $sheet->getStyle("{$colLetter}{$row}")->applyFromArray([
            'font' => [
                'bold' => true,
                'size' => 12
            ],
            'alignment' => [
                'horizontal' => Alignment::HORIZONTAL_CENTER,
                'vertical' => Alignment::VERTICAL_CENTER
            ]
        ]);

        
    }

    
    $mergeEndCol = Coordinate::stringFromColumnIndex((int)$mergeEndIndex + 1);
    $mergeRange = "{$startCol}{$row}:{$mergeEndCol}{$row}";

    // Merge cells and write $label name = "TOTAL"
    $sheet->mergeCells($mergeRange);
    $sheet->setCellValue("{$startCol}{$row}", $label);

     // Style "TOTAL" label
     $sheet->getStyle($mergeRange)->applyFromArray([
        'font' => [
            'bold' => true,
            'size' => 14,
            'color' => ['rgb' => $code]
        ],
        'alignment' => [
            'horizontal' => Alignment::HORIZONTAL_CENTER,
            'vertical' => Alignment::VERTICAL_CENTER
        ]
    ]);

    // Return next row cell reference
    return $startCol . ($row + 1);
}