RefactoredDataGenerator.php

<?php

class Generator {
    private const JSON_TYPE = ‘application/json’;
    private const CSV_TYPE = ‘text/csv’;
    private const JSON_EXT = ‘json’;
    private const CSV_EXT = ‘csv’;

    private function disposition(
        string $filename, 
        string $content,
        string $fileType,
    ): void {
        $ext = $fileType == self::JSON_TYPE ? self::JSON_EXT : self::CSV;
        header(“Content-Type: $fileType”);
        header(sprintf(‘Content-Disposition: attachment; filename="%s”`), sprintf(‘%s.%s’, $filename, $ext);
        ob_start();
        echo $content;
        ob_end_flush();
        exit;
    } 
    private function generateContent(
        array $data, 
        string $fileType
    ): string {
        return match($fileType) {
            self::JSON_TYPE => $this->generateJsonContent($data),
            self::CSV_TYPE => $this->generateCSVContent($data),
            default: throw new UnexpectedContentType(),
        };
    }
    private function generateCSVContent(array $data): string
    {
        $stream = fopen(‘php://memory’);
        
        foreach ($data as $line) {
            fputcsv($stream, $data, ‘;’);
        }
        
        $content = ‘’;
        while (false === feof($stream)) {
            $content .= fread($stream, 1024);
        }
        fclose($stream);
        return $content;
    }
    
    private function generateJsonContent(array $data): string
    {
        return json_encode($data);
    }
    // . . . 

}