NewHome/nav.php

<?php
/**
 * nav.php —— 导航区模板（科普库 / 红队库 / 蓝队库共用）
 * URL 参数：cat=popular | red | blue
 * 布局：顶部留白区（含小型品牌条）→ 搜索栏 → 三大列导航块区
 */
$P = '';
require_once __DIR__ . '/includes/layout.php';

$catKey = isset($_GET['cat']) ? (string)$_GET['cat'] : '';
$allowed = ['popular', 'red', 'blue'];
if (!in_array($catKey, $allowed, true)) {
    // 非法或缺失分类：默认指向科普库更友好（导航页只承载三大知识库）
    $catKey = 'popular';
}

$pdo = db();
$st = $pdo->prepare('SELECT * FROM categories WHERE key = ? LIMIT 1');
$st->execute([$catKey]);
$cat = $st->fetch();
if (!$cat) {
    http_response_code(404);
    layout_head('导航页不存在');
    echo '<main class="page-main"><div class="wrap"><div class="err-msg">导航分类不存在，请返回首页。</div></div></main>';
    layout_theme_fab();
    layout_footer();
    echo '<script src="assets/js/common.js"></script></body></html>';
    exit;
}

// 块与按钮数据
$st = $pdo->prepare('SELECT * FROM nav_blocks WHERE cat_id = ? ORDER BY sort ASC, id ASC');
$st->execute([(int)$cat['id']]);
$blocks = $st->fetchAll();

$itemsByBlock = [];
if ($blocks) {
    $ids = array_map(function ($b) { return (int)$b['id']; }, $blocks);
    $in = implode(',', array_fill(0, count($ids), '?'));
    $st = $pdo->prepare("SELECT * FROM nav_items WHERE block_id IN ($in) ORDER BY sort ASC, id ASC");
    $st->execute($ids);
    foreach ($st->fetchAll() as $item) {
        $itemsByBlock[(int)$item['block_id']][] = $item;
    }
}

// 三列轮转分配（保证列内块数均衡）
$cols = [[], [], []];
$idx = 0;
foreach ($blocks as $b) {
    $cols[$idx % 3][] = $b;
    $idx++;
}
$totalItems = 0;
foreach ($itemsByBlock as $list) {
    $totalItems += count($list);
}

$siteName = setting_get('site_name', '知识导航站');
$engines = search_engines();
$defaultEngine = $engines[0]['key'] ?? 'bing';
$enginesJson = json_encode($engines, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

layout_head((string)$cat['name']);
?>
<!-- 顶部留白 + 品牌条 -->
<div class="nav-top">
  <div class="wrap" style="display:flex;justify-content:space-between;align-items:flex-start;gap:10px;flex-wrap:wrap;">
    <a class="brand brand-sm" href="index.php" title="返回首页">
      <?php layout_logo_img('logo', $siteName); ?>
      <span class="site-name"><?= he($siteName) ?></span>
    </a>
    <span class="board-tag" style="font-size:13px;color:var(--text-3);padding-top:10px;"><?= he((string)$cat['name']) ?></span>
  </div>
</div>

<!-- 搜索栏 -->
<div class="search-zone">
  <div class="wrap">
    <div class="search-box js-search" data-engine="<?= he($defaultEngine) ?>" data-engines="<?= he($enginesJson) ?>">
      <button type="button" class="engine-btn js-engine-btn" title="切换搜索引擎">
        <span class="js-engine-name"><?= he($engines[0]['icon'] ?? 'S') ?></span>
        <span class="arrow">▼</span>
        <ul class="engine-menu js-engine-menu"></ul>
      </button>
      <div class="search-field">
        <input type="text" class="js-search-input" placeholder="输入关键词，回车或点击搜索…" autocomplete="off">
        <button type="button" class="search-clear js-search-clear" title="清除">✕</button>
      </div>
      <button type="button" class="search-go js-search-go">搜索</button>
    </div>
    <p class="search-title">可切换搜索引擎进行搜索（<?= count($engines) ?> 个可用，后台可维护）</p>
  </div>
</div>

<!-- 导航内容区：左右各留白 15%，中间三大列 -->
<div class="nav-area">
  <div class="nav-area-head">
    <span class="nav-area-title"><?= he((string)$cat['name']) ?></span>
    <span class="nav-area-count">共 <?= count($blocks) ?> 个导航块 / <?= $totalItems ?> 个链接</span>
  </div>

  <?php if (!$blocks): ?>
    <div class="panel-card"><div class="tip">该库还没有导航内容，可在后台"导航内容管理"中添加。</div></div>
  <?php else: ?>
    <div class="nav-cols">
      <?php foreach ($cols as $colIdx => $colBlocks): ?>
        <div class="nav-col">
          <?php foreach ($colBlocks as $b):
            $items = $itemsByBlock[(int)$b['id']] ?? [];
            $show = array_slice($items, 0, 15);
            ?>
            <div class="nav-block">
              <div class="nav-block-title"><?= he((string)$b['title']) ?></div>
              <div class="nav-block-grid">
                <?php for ($i = 0; $i < 15; $i++): ?>
                  <?php if (isset($show[$i])):
                    $it = $show[$i];
                    $label = (string)$it['label'];
                    $url = trim((string)$it['url']);
                    $note = trim((string)$it['note']);
                    if ($url !== ''): ?>
                      <a class="nav-btn" href="<?= he($url) ?>" target="_blank" rel="noopener noreferrer"<?php if ($note !== ''): ?> data-note="<?= he($note) ?>"<?php endif; ?>><?= he($label ?: $url) ?></a>
                    <?php else: ?>
                      <span class="nav-btn is-off" title="链接未配置"><?= he($label) ?></span>
                    <?php endif; ?>
                  <?php else: ?>
                    <span class="nav-btn is-empty"></span>
                  <?php endif; ?>
                <?php endfor; ?>
              </div>
            </div>
          <?php endforeach; ?>
        </div>
      <?php endforeach; ?>
    </div>
  <?php endif; ?>
</div>

<?php layout_theme_fab(); ?>
<?php layout_footer(); ?>

<script src="assets/js/common.js"></script>
</body>
</html>