<?php

class MediaDB
{
    private $handler;
    private array $lines = [];

    public function __construct()
    {
        // Just initialize the file handler
        $this->handler = fopen($GLOBALS['path_mediadb'], 'r');
        if ($this->handler === false)
            Json::error('Error opening media DB');
    }

    private function getLine(): ?array
    {
        $ret = fgetcsv($this->handler, 0, ' ');
        if ($ret === false)
            return null;

        return $ret;
    }

    public function map(callable $func)
    {
        // First read from what's already in memory
        foreach ($this->lines as $i_line) {
            if ($func($i_line) === true) return;
        }

        // If we run out, read from the file and append to array so the next lookup
        // is fast
        while ($line = $this->getLine()) {
            $this->lines[] = $line;

            if ($func($line) === true) return;
        }
    }
}