<?php
// 头像代理：转发 https://api.iyuns.com/api/head 并返回 { url }
header('Content-Type: application/json; charset=utf-8');

$endpoint = 'https://api.iyuns.com/api/head';

function fetch_json($url) {
    $ch = curl_init($url);
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_CONNECTTIMEOUT => 8,
        CURLOPT_TIMEOUT => 12,
        CURLOPT_SSL_VERIFYPEER => false,
        CURLOPT_SSL_VERIFYHOST => false,
        CURLOPT_USERAGENT => 'DiscussionProxy/1.0',
    ]);
    $body = curl_exec($ch);
    $err  = curl_error($ch);
    curl_close($ch);
    if ($err) { return null; }
    $json = json_decode($body, true);
    return is_array($json) ? $json : null;
}

$resp = fetch_json($endpoint);
$url = '';
if ($resp && ($resp['code'] ?? 0) == 200) {
    $url = preg_replace('/[`\s]/', '', (string)($resp['data'] ?? ''));
}
if (!$url) {
    // 远程失败时，回退到本地随机头像（遍历 avatars 下所有日期目录）
    $root = __DIR__ . '/../avatars';
    $candidates = [];
    if (is_dir($root)) {
        $rii = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($root));
        foreach ($rii as $file) {
            if ($file->isFile()) {
                $ext = strtolower(pathinfo($file->getFilename(), PATHINFO_EXTENSION));
                if (in_array($ext, ['jpg','jpeg','png','gif','webp'])) {
                    $rel = str_replace('\\', '/', str_replace($_SERVER['DOCUMENT_ROOT'], '', $file->getPathname()));
                    $candidates[] = $rel;
                }
            }
        }
        if (!empty($candidates)) {
            shuffle($candidates);
            $url = $candidates[0];
        }
    }
    // 如果本地也没有，则后备一个 Unsplash 头像
    if (!$url) {
        $url = 'https://images.unsplash.com/photo-1547425260-76bcadfb4f9b?w=200&h=200&fit=crop';
    }
}

echo json_encode(['url' => $url], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);