<?php
// IfNoneMatchHeader.php
// Created: 2022-02-14
// Updated: 2022-02-27

namespace Index\Http\Headers;

use Index\Http\HttpHeader;

class IfNoneMatchHeader {
    private array $tags;
    private int $count;

    public function __construct(array $tags) {
        $this->tags = $tags;
        $this->count = count($tags);
    }

    public function getTags(): array {
        return $this->tags;
    }

    public function hasTag(string $tag): bool {
        if($this->count === 1 && $this->tags[0] === '*')
            return true;
        return in_array($tag, $this->tags);
    }

    public static function parse(HttpHeader $header): IfNoneMatchHeader {
        $tags = [];
        $rawTags = array_unique(
            array_map(
                fn($directive) => trim($directive),
                explode(',', strtolower($header->getFirstLine()))
            )
        );

        foreach($rawTags as $raw) {
            if(str_starts_with($raw, 'W/"'))
                $raw = substr($raw, 2);
            $tags[] = trim($raw, '"');
        }

        return new IfNoneMatchHeader($tags);
    }
}