<?php

namespace App\Services;

class CsvReader {
    private $file;
    private array $headers;

    public array $lines = [];

    public function __construct(
        public string $filename,
    )
    {
        $this->file = fopen($filename, "r");
        if (!$this->file) {
            throw new \RuntimeException("Failed to open file: " . $filename);
        }

        $this->headers = $this->readNextLine();
    }

    public function readNextLine(): ?array
    {
        if (($data = fgetcsv($this->file, 1000, ",")) !== FALSE) {
            return $data;
        }
        return null; // End of file or error
    }
}