autocde2.0/app/Exports/ProjectGanttExport.php

<?php

namespace App\Exports;

use App\Models\Project;
use App\Services\Project\ProjectGanttService;
use Illuminate\Support\Collection;
use Maatwebsite\Excel\Concerns\Exportable;
use Maatwebsite\Excel\Concerns\FromCollection;
use Maatwebsite\Excel\Concerns\ShouldAutoSize;
use Maatwebsite\Excel\Concerns\WithHeadings;
use Maatwebsite\Excel\Concerns\WithMapping;
use Maatwebsite\Excel\Events\AfterSheet;
use PhpOffice\PhpSpreadsheet\Style\NumberFormat;


class ProjectGanttExport implements FromCollection, WithMapping, ShouldAutoSize
{
    use Exportable;
    private static $index = 1;
    public function collection()
    {
        $project = Project::allowed(request()->project_id)->findOrFail(request()->project_id);

        $group = in_array(
            request()->get("group"),
            ['requirement_id','assign','task_type']
        ) ? request()->get("group") : "task_type";
        $header = ['id'=>'ID','parent'=> 0,'text'=>'Folder','start_date'=>'Start_Date','end_date'=>'End_Date','progress'=>'Progress','assign_to'=>'Assign_To'];
        $gantt = (new ProjectGanttService())->gantt($project, $group);
        array_unshift($gantt,$header);
        return new Collection($gantt);
    }

    public function map($project): array
    {
        $folder = '';
        if ($project['parent'] == 0){
            $folder = $project['text'];
            $displayId = $project['id'] =='ID'?'ID':'';
            $project['text'] =  $project['text']=='Folder'?'Name':'';
        }else{
            $displayId = self::$index++;
        }
        return [
            $folder,
            $displayId,
            $project['text'],
            $project['parent'] != 0 ? ($project['progress'] * 100) . '%' : ($project['progress'] == 'Progress' ? 'Progress' : ''),
            $project['start_date'],
            $project['end_date'],
            $project['assign_to'],
        ];
    }



}