<?php
namespace ProVM\Common\Implement;

use Exception;
use ProVM\Common\Define\Log;
use ProVM\Logview\Exception\Parse\EmptyException;
use ProVM\Logview\Exception\Parse\EmptyLineException;
use ProVM\Logview\Log as LogContent;
use ProVM\Common\Define\Parser as Definition;
use function Safe\{fopen, fclose};

abstract class Parser implements Definition
{
    public function isMultiline(string $filename): bool
    {
        return false;
    }

    public function total(string $filename): int
    {
        try {
            $fh = fopen($filename, 'r');
            $cnt = 0;
            while(!feof($fh)) {
                $line = fgets($fh);
                $cnt ++;
            }
            fclose($fh);
            return $cnt;
        } catch (Exception $e) {
            return 0;
        }
    }
    public function parse(mixed &$file_handler): Log
    {
        $content = fgets($file_handler);
        if (!$content) {
            $meta_data = stream_get_meta_data($file_handler);
            throw new EmptyException($meta_data['uri'], ftell($file_handler));
        }
        if (trim($content) === '') {
            $meta_data = stream_get_meta_data($file_handler);
            throw new EmptyLineException($meta_data['uri'], ftell($file_handler));
        }
        return new LogContent($content);
    }
    public function advance(mixed &$file_handler, int $offset): void
    {
        if ($offset === 0) {
            return;
        }
        $cnt = 0;
        while(!feof($file_handler)) {
            fgets($file_handler);
            $cnt ++;
            if ($cnt >= $offset) {
                break;
            }
        }
    }
}