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

namespace Index\Http\Headers;

use DateTimeInterface;
use Index\DateTime;
use Index\Http\HttpHeader;

class IfRangeHeader {
    private ?string $tag;
    private ?DateTime $dateTime;

    public function __construct(?string $tag, ?DateTime $dateTime) {
        $this->tag = $tag;
        $this->dateTime = $dateTime;
    }

    public function hasTag(): bool {
        return $this->tag !== null;
    }

    public function getTag(): string {
        return $this->tag;
    }

    public function hasDateTime(): bool {
        return $this->dateTime !== null;
    }

    public function getDateTime(): DateTime {
        return $this->dateTime;
    }

    public function matches(string|DateTimeInterface $other): bool {
        if($this->hasTag() && is_string($other)) {
            if(str_starts_with($other, 'W/"'))
                return false;
            return $this->tag === $other;
        }

        if($this->hasDateTime() && $other instanceof DateTimeInterface)
            return $this->dateTime->isLessThanOrEqual($other);

        return false;
    }

    public static function parse(HttpHeader $header): IfRangeHeader {
        $line = $header->getFirstLine();

        if($line[0] !== '"' && !str_starts_with($line, 'W/"'))
            return new IfRangeHeader(null, DateTime::createFromFormat(\DateTimeInterface::RFC7231, $line));

        return new IfRangeHeader($line, null);
    }
}