ringularity/index.php

<?php

declare(strict_types=1);

header("Content-Type: text/html; charset=UTF-8");
header("X-Content-Type-Options: nosniff");
header("Referrer-Policy: strict-origin-when-cross-origin");
header("Permissions-Policy: geolocation=(), microphone=(), camera=()");
header(
    "Content-Security-Policy: default-src 'none'; base-uri 'none'; form-action 'none'; frame-ancestors *",
);
if (function_exists("header_remove")) {
    header_remove("X-Frame-Options");
}

function normalizeHost(string $value): ?string
{
    $value = trim(strtolower($value));

    if ($value === "") {
        return null;
    }

    if (preg_match("#^https?://#", $value) === 1) {
        $parsedHost = parse_url($value, PHP_URL_HOST);
        if (!is_string($parsedHost) || $parsedHost === "") {
            return null;
        }
        $value = strtolower($parsedHost);
    }

    $value = explode("/", $value, 2)[0];

    if (
        preg_match(
            "/\A(?=.{1,253}\z)(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?\.)+[a-z]{2,63}\z/",
            $value,
        ) !== 1
    ) {
        return null;
    }

    return $value;
}

$rawSites = file(
    __DIR__ . "/sites.txt",
    FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES,
);
if ($rawSites === false) {
    http_response_code(500);
    echo ";_;";
    exit();
}

$sites = [];
foreach ($rawSites as $rawSite) {
    $normalized = normalizeHost($rawSite);
    if ($normalized !== null) {
        $sites[] = $normalized;
    }
}
$sites = array_values(array_unique($sites));

if (count($sites) < 2) {
    http_response_code(500);
    echo "did't find at least two sites to ring among";
    exit();
}

$current = normalizeHost((string) ($_GET["site"] ?? ""));
if ($current === null) {
    http_response_code(400);
    echo "genuinely what are we doing here";
    exit();
}

$index = array_search($current, $sites, true);
if ($index === false) {
    http_response_code(404);
    echo "This site isn't actually part of the ringularity ;-;";
    exit();
}

$total = count($sites);
$prev = $sites[($index - 1 + $total) % $total];
$next = $sites[($index + 1) % $total];
?>
<div id="ring" role="navigation" aria-label="Webring navigation">
    <a href="https://<?= htmlspecialchars(
        $prev,
        ENT_QUOTES | ENT_SUBSTITUTE,
        "UTF-8",
    ) ?>" target="_top" rel="noopener noreferrer">&larr; PREV</a>
    <span aria-hidden="true" class="specialtxt">The Ringularity</span>
    <a href="https://<?= htmlspecialchars(
        $next,
        ENT_QUOTES | ENT_SUBSTITUTE,
        "UTF-8",
    ) ?>" target="_top" rel="noopener noreferrer">NEXT &rarr;</a>
</div>

<style>
:root {
    --bg-1: #1d2021;
    --bg0: #282828;
    --bg1: #3c3836;
    --bg2: #504945;
    --bg3: #665c54;
    --bg4: #7c6f64;

    --gray0: #928374;
    --gray1: #a89984;

    --fg0: #fbf1c7;
    --fg1: #ebdbb2;
    --fg2: #d5c4a1;
    --fg3: #bdae93;

    --red0: #cc241d;
    --red1: #fb4934;

    --green0: #98971a;
    --green1: #b8bb26;

    --yellow0: #d79921;
    --yellow1: #fabd2f;

    --blue0: #458588;
    --blue1: #83a598;

    --purple0: #b16286;
    --purple1: #d3869b;

    --aqua0: #689d6a;
    --aqua1: #8ec07c;

    --orange0: #d65d0e;
    --orange1: #fe8019;
}
#ring {
                border-radius: var(--brad);
                background-color: var(--bg2);
                color: var(--blue1);
                transition: scale 0.2s linear;
                display: flex;
                flex-direction: row;
                justify-content: space-between;
                flex-wrap: nowrap;
                height: 1em;
                padding: 1em;
                align-items: center;
            }

            #ring:hover a {
                transition: transform 1.3s ease-in-out;
                transform: scaleX(4) scaleY(1.5);
                animation: wheee 0.2s linear infinite;
                animation-delay: 1.3s;
            }

            #ring:hover .specialtxt {
                font-weight: bold;
                text-transform: uppercase;
                position: relative;
                animation: bob 1.8s infinite ease-in-out;
                background: linear-gradient(
                    90deg,
                    var(--red1),
                    var(--orange1),
                    var(--yellow1)
                );
                -webkit-background-clip: text;
                color: transparent;
            }

            #ring:hover .specialtxt::before,
            #ring:hover .specialtxt::after {
                content: "The Ringularity";
                position: absolute;
                top: 0;
                left: 0;
                width: 100%;
                height: 100%;
                background: linear-gradient(
                    90deg,
                    var(--red0),
                    var(--orange0),
                    var(--yellow0)
                );
                -webkit-background-clip: text;
                color: transparent;
                z-index: -1;
                transform: scaleY(1);
                opacity: 0.5;
                animation: smear 1.8s infinite ease-in-out;
            }

            #ring:hover .specialtxt::after {
                filter: blur(8px);
                opacity: 0.8;
            }

            @keyframes bob {
                0%,
                100% {
                    transform: translateY(8px) scaleX(1.2) scaleY(0.8);
                }
                50% {
                    transform: translateY(-8px) scaleX(0.8) scaleY(1.2);
                }
            }

            @keyframes smear {
                0%,
                100%,
                50% {
                    transform: scaleY(1) translateY(0px);
                    opacity: 0.5;
                }
                25% {
                    transform: scaleY(1.5) translateY(2px);
                    opacity: 0.7;
                }
                75% {
                    transform: scaleY(1.5) translateY(-2px);
                    opacity: 0.7;
                }
            }

            @keyframes wheee {
                from {
                    transform: rotate(0deg) scaleX(4) scaleY(1.5);
                }
                to {
                    transform: rotate(360deg) scaleX(4) scaleY(1.5);
                }
            }
</style>