SimpleNav/functions.php

<?php
/**
 * 简航 SimpleNav —— 公共函数
 */
declare(strict_types=1);

require_once __DIR__ . '/config.php';
require_once __DIR__ . '/db.php';

/** HTML 转义 */
function e(?string $s): string
{
    return htmlspecialchars((string)$s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
}

/** 规范化 URL：补协议、去空白 */
function norm_url(string $url): string
{
    $url = trim($url);
    if ($url === '') {
        return '';
    }
    if (!preg_match('#^https?://#i', $url)) {
        $url = 'http://' . $url;
    }
    return $url;
}

/** 取主域名（用于 favicon 与文件名） */
function domain_of(string $url): string
{
    $host = parse_url(norm_url($url), PHP_URL_HOST);
    return $host ? preg_replace('/^www\./i', '', $host) : '';
}

/** curl 抓取文本（带 UA、超时、跟随跳转、限长） */
function http_get(string $url, int $maxBytes = 300000, int $timeout = 8): ?array
{
    if (!function_exists('curl_init')) {
        // 兜底：allow_url_fopen
        $ctx = stream_context_create(['http' => [
            'timeout' => $timeout,
            'header' => "User-Agent: Mozilla/5.0 SimpleNav\r\n",
            'follow_location' => 1,
        ]]);
        $body = @file_get_contents($url, false, $ctx, 0, $maxBytes);
        if ($body === false) {
            return null;
        }
        return ['body' => $body, 'url' => $url, 'type' => ''];
    }
    $ch = curl_init($url);
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_FOLLOWLOCATION => true,
        CURLOPT_MAXREDIRS => 5,
        CURLOPT_TIMEOUT => $timeout,
        CURLOPT_CONNECTTIMEOUT => 5,
        CURLOPT_USERAGENT => 'Mozilla/5.0 (compatible; SimpleNav/1.0)',
        CURLOPT_SSL_VERIFYPEER => false,
        CURLOPT_SSL_VERIFYHOST => 0,
        CURLOPT_ENCODING => '',
    ]);
    $body = curl_exec($ch);
    $type = (string)curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
    $eff  = (string)curl_getinfo($ch, CURLINFO_EFFECTIVE_URL);
    $err  = curl_errno($ch);
    curl_close($ch);
    if ($err || $body === false) {
        return null;
    }
    return ['body' => $body, 'url' => $eff ?: $url, 'type' => $type];
}

/**
 * 抓取网站元信息：标题、名称、图标地址。
 * @return array{title:string,name:string,icon:string,final_url:string}
 */
function fetch_site_meta(string $url): array
{
    $url = norm_url($url);
    $out = ['title' => '', 'name' => '', 'icon' => '', 'final_url' => $url];
    $resp = http_get($url);
    if ($resp === null) {
        return $out;
    }
    $html = $resp['body'];
    $final = $resp['url'];
    $out['final_url'] = $final;

    // 编码：优先按 <meta charset> 转换到 UTF-8
    $html = ensure_utf8($html);

    // <title>
    if (preg_match('#<title[^>]*>(.*?)</title>#is', $html, $m)) {
        $out['title'] = trim(preg_replace('/\s+/', ' ', html_entity_decode($m[1], ENT_QUOTES, 'UTF-8')));
    }
    // og:site_name 优先作为"名称"
    if (preg_match('#<meta[^>]+property=["\']og:site_name["\'][^>]+content=["\']([^"\']+)#i', $html, $m)) {
        $out['name'] = trim(html_entity_decode($m[1], ENT_QUOTES, 'UTF-8'));
    } elseif ($out['title'] !== '') {
        // 用标题的首段（按分隔符切分）作为名称
        $t = preg_split('#[\|\-_—·:：]#u', $out['title']);
        $out['name'] = trim($t[0]);
    }

    // 图标：<link rel="...icon...">
    $icon = '';
    if (preg_match_all('#<link[^>]+>#i', $html, $links)) {
        foreach ($links[0] as $tag) {
            if (preg_match('#rel=["\'][^"\']*icon[^"\']*["\']#i', $tag)) {
                if (preg_match('#href=["\']([^"\']+)["\']#i', $tag, $hm)) {
                    $cand = html_entity_decode($hm[1], ENT_QUOTES, 'UTF-8');
                    // 优先 apple-touch-icon（通常更大更清晰）
                    if (stripos($tag, 'apple-touch') !== false) {
                        $icon = $cand;
                        break;
                    }
                    if ($icon === '') {
                        $icon = $cand;
                    }
                }
            }
        }
    }
    if ($icon !== '') {
        $out['icon'] = absolutize($icon, $final);
    } else {
        $p = parse_url($final);
        if (!empty($p['scheme']) && !empty($p['host'])) {
            $out['icon'] = $p['scheme'] . '://' . $p['host'] . '/favicon.ico';
        }
    }
    return $out;
}

/** 把可能为相对路径的 URL 补全为绝对 URL */
function absolutize(string $href, string $base): string
{
    if (preg_match('#^https?://#i', $href)) {
        return $href;
    }
    $p = parse_url($base);
    $root = ($p['scheme'] ?? 'http') . '://' . ($p['host'] ?? '');
    if (strpos($href, '//') === 0) {
        return ($p['scheme'] ?? 'http') . ':' . $href;
    }
    if (strpos($href, '/') === 0) {
        return $root . $href;
    }
    $dir = rtrim(dirname($p['path'] ?? '/'), '/');
    return $root . $dir . '/' . $href;
}

/** 简单编码归一：识别 GBK/GB18030 并转 UTF-8 */
function ensure_utf8(string $s): string
{
    if (preg_match('#<meta[^>]+charset=["\']?\s*(gbk|gb2312|gb18030)#i', $s)) {
        if (function_exists('mb_convert_encoding')) {
            return mb_convert_encoding($s, 'UTF-8', 'GB18030');
        }
    }
    if (function_exists('mb_check_encoding') && !mb_check_encoding($s, 'UTF-8')) {
        return mb_convert_encoding($s, 'UTF-8', 'GB18030');
    }
    return $s;
}

/**
 * 下载图标并保存到本地（PNG，64x64，透明背景）。
 * @return string 本地文件名（如 ab12cd.png），失败返回 ''
 */
function download_icon(string $iconUrl, string $key, int $size = 64): string
{
    if ($iconUrl === '') {
        return '';
    }
    if (!is_dir(ICON_PATH)) {
        @mkdir(ICON_PATH, 0755, true);
    }
    $resp = http_get($iconUrl, 500000, 8);
    if ($resp === null || $resp['body'] === '') {
        return '';
    }
    $bin = $resp['body'];
    $name = md5($key) . '.png';
    $dest = ICON_PATH . '/' . $name;

    // 用 GD 统一转成 PNG（顺带裁成正方形、缩放）
    if (function_exists('imagecreatefromstring')) {
        $im = @imagecreatefromstring($bin);
        if ($im !== false) {
            $w = imagesx($im);
            $h = imagesy($im);
            $side = min($w, $h);
            $square = imagecreatetruecolor($size, $size);
            imagealphablending($square, false);
            imagesavealpha($square, true);
            $trans = imagecolorallocatealpha($square, 0, 0, 0, 127);
            imagefill($square, 0, 0, $trans);
            $sx = (int)(($w - $side) / 2);
            $sy = (int)(($h - $side) / 2);
            imagecopyresampled($square, $im, 0, 0, $sx, $sy, $size, $size, $side, $side);
            imagepng($square, $dest);
            imagedestroy($square);
            imagedestroy($im);
            return $name;
        }
    }
    // 无 GD：原样保存（按 content-type 猜扩展名）
    $ext = 'ico';
    if (stripos($resp['type'], 'png') !== false) {
        $ext = 'png';
    } elseif (stripos($resp['type'], 'svg') !== false) {
        $ext = 'svg';
    } elseif (stripos($resp['type'], 'jpeg') !== false || stripos($resp['type'], 'jpg') !== false) {
        $ext = 'jpg';
    } elseif (stripos($resp['type'], 'gif') !== false) {
        $ext = 'gif';
    }
    $name = md5($key) . '.' . $ext;
    @file_put_contents(ICON_PATH . '/' . $name, $bin);
    return is_file(ICON_PATH . '/' . $name) ? $name : '';
}

/** 图标显示地址（为空时返回 ''，前端回退到首字母块） */
function icon_src(string $file): string
{
    return $file === '' ? '' : url(ICON_URL . '/' . $file);
}

/** 名称首字配色（无图标时的回退头像底色） */
function letter_color(string $s): string
{
    $palette = ['#2F6BF7', '#5B8DEF', '#0EA5E9', '#10B981', '#F59E0B', '#EF4444', '#8B5CF6', '#EC4899', '#14B8A6', '#F97316'];
    return $palette[abs(crc32($s)) % count($palette)];
}