<?php
require_once __DIR__ . '/../includes/bootstrap.php';
$admin = require_admin_or_permission('manage_kb');
$pdo = get_db();

$errors = [];

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    verify_csrf();
    $action = $_POST['action'] ?? '';

    if ($action === 'create_category') {
        $name = trim($_POST['name'] ?? '');
        if ($name === '') {
            $errors[] = 'Bitte einen Kategorienamen angeben.';
        } else {
            $slug = slugify($name);
            $pdo->prepare('INSERT INTO kb_categories (name, slug, sort_order) VALUES (?,?,0)')->execute([$name, $slug]);
            if (function_exists('dhcm_cache_clear')) dhcm_cache_clear();
            audit_log($admin['id'], "KB-Kategorie erstellt: {$name}");
            flash('success', 'Kategorie erstellt.');
            redirect('/staff/kb_manage.php');
        }
    }

    if ($action === 'delete_category') {
        $id = (int) $_POST['id'];
        $stmt = $pdo->prepare('SELECT COUNT(*) FROM kb_articles WHERE category_id = ?');
        $stmt->execute([$id]);
        if ((int) $stmt->fetchColumn() > 0) {
            flash('error', 'Diese Kategorie enthält noch Artikel und kann nicht gelöscht werden.');
        } else {
            $nameStmt = $pdo->prepare('SELECT name FROM kb_categories WHERE id = ?');
            $nameStmt->execute([$id]);
            $catName = $nameStmt->fetchColumn();
            $pdo->prepare('DELETE FROM kb_categories WHERE id = ?')->execute([$id]);
            if (function_exists('dhcm_cache_clear')) dhcm_cache_clear();
            audit_log($admin['id'], "KB-Kategorie gelöscht: {$catName}");
            flash('success', 'Kategorie gelöscht.');
        }
        redirect('/staff/kb_manage.php');
    }

    if ($action === 'save_article') {
        $id = $_POST['id'] ?? '';
        $title = trim($_POST['title'] ?? '');
        $categoryId = (int) ($_POST['category_id'] ?? 0);
        $body = sanitize_staff_html($_POST['body'] ?? '');
        $isPublished = !empty($_POST['is_published']) ? 1 : 0;

        if ($title === '') $errors[] = 'Bitte einen Titel angeben.';
        if (trim(strip_tags($body)) === '') $errors[] = 'Bitte einen Inhalt angeben.';

        if (!$errors) {
            if ($id === '') {
                $slug = slugify($title);
                $base = $slug; $i = 2;
                $check = $pdo->prepare('SELECT COUNT(*) FROM kb_articles WHERE slug = ?');
                while (true) {
                    $check->execute([$slug]);
                    if ((int) $check->fetchColumn() === 0) break;
                    $slug = $base . '-' . $i++;
                }
                $pdo->prepare('INSERT INTO kb_articles (category_id, title, slug, body, is_published, created_at, updated_at) VALUES (?,?,?,?,?,?,?)')
                    ->execute([$categoryId, $title, $slug, $body, $isPublished, db_now(), db_now()]);
                audit_log($admin['id'], "KB-Artikel erstellt: {$title}");
                flash('success', 'Artikel erstellt.');
            } else {
                $pdo->prepare('UPDATE kb_articles SET category_id=?, title=?, body=?, is_published=?, updated_at=? WHERE id=?')
                    ->execute([$categoryId, $title, $body, $isPublished, db_now(), (int) $id]);
                audit_log($admin['id'], "KB-Artikel aktualisiert: {$title}");
                flash('success', 'Artikel aktualisiert.');
            }
            if (function_exists('dhcm_cache_clear')) dhcm_cache_clear();
            redirect('/staff/kb_manage.php');
        }
    }

    if ($action === 'delete_article') {
        $id = (int) $_POST['id'];
        $titleStmt = $pdo->prepare('SELECT title FROM kb_articles WHERE id = ?');
        $titleStmt->execute([$id]);
        $artTitle = $titleStmt->fetchColumn();
        $pdo->prepare('DELETE FROM kb_articles WHERE id = ?')->execute([$id]);
        if (function_exists('dhcm_cache_clear')) dhcm_cache_clear();
        audit_log($admin['id'], "KB-Artikel gelöscht: {$artTitle}");
        flash('success', 'Artikel gelöscht.');
        redirect('/staff/kb_manage.php');
    }
}

$categories = $pdo->query('SELECT * FROM kb_categories ORDER BY sort_order, name')->fetchAll();
$articles = $pdo->query(
    'SELECT a.*, c.name AS category_name FROM kb_articles a JOIN kb_categories c ON c.id=a.category_id ORDER BY a.title'
)->fetchAll();

$editId = $_GET['edit'] ?? null;
$editArticle = null;
if ($editId) {
    $stmt = $pdo->prepare('SELECT * FROM kb_articles WHERE id = ?');
    $stmt->execute([$editId]);
    $editArticle = $stmt->fetch();
}
$showForm = isset($_GET['new']) || $editArticle;

$pageTitle = 'Wissensdatenbank';
$activePage = 'kb';
require __DIR__ . '/_header.php';
?>

<h1>Wissensdatenbank verwalten</h1>

<?php foreach ($errors as $err): ?>
  <div class="flash error"><?= e($err) ?></div>
<?php endforeach; ?>

<div style="display:flex; gap:24px; align-items:flex-start">
  <div style="flex:2; min-width:0">

    <?php if ($showForm): ?>
      <div class="card">
        <h3><?= $editArticle ? 'Artikel bearbeiten' : 'Neuer Artikel' ?></h3>
        <form method="post">
          <?= csrf_field() ?>
          <input type="hidden" name="action" value="save_article">
          <?php if ($editArticle): ?><input type="hidden" name="id" value="<?= $editArticle['id'] ?>"><?php endif; ?>
          <label for="title">Titel</label>
          <input type="text" id="title" name="title" value="<?= e($editArticle['title'] ?? '') ?>" required>
          <label for="category_id">Kategorie</label>
          <select name="category_id" id="category_id" required>
            <?php foreach ($categories as $c): ?>
              <option value="<?= $c['id'] ?>" <?= ($editArticle['category_id'] ?? '') == $c['id'] ? 'selected' : '' ?>><?= e($c['name']) ?></option>
            <?php endforeach; ?>
          </select>
          <label for="body">Inhalt (HTML erlaubt)</label>
          <textarea id="body" name="body" data-richtext style="min-height:220px" required><?= e($editArticle['body'] ?? '') ?></textarea>
          <label style="display:flex; align-items:center; gap:8px; margin-top:14px">
            <input type="checkbox" name="is_published" style="width:auto" <?= ($editArticle['is_published'] ?? 1) ? 'checked' : '' ?>>
            Veröffentlicht
          </label>
          <div class="btn-row">
            <button type="submit" class="btn">Speichern</button>
            <a href="/staff/kb_manage.php" class="btn secondary">Abbrechen</a>
          </div>
        </form>
      </div>
    <?php endif; ?>

    <div class="card">
      <div class="topbar" style="margin-bottom:10px"><h3 style="margin:0">Artikel</h3><a href="/staff/kb_manage.php?new=1" class="btn secondary">+ Neuer Artikel</a></div>
      <table>
        <thead><tr><th>Titel</th><th>Kategorie</th><th>Status</th><th>Aufrufe</th><th></th></tr></thead>
        <tbody>
          <?php foreach ($articles as $a): ?>
            <tr>
              <td><?= e($a['title']) ?></td>
              <td><?= e($a['category_name']) ?></td>
              <td><?= $a['is_published'] ? '<span class="badge" style="background:#16a34a">Live</span>' : '<span class="badge" style="background:#6b7280">Entwurf</span>' ?></td>
              <td><?= (int) $a['views'] ?></td>
              <td>
                <a href="/staff/kb_manage.php?edit=<?= $a['id'] ?>">Bearbeiten</a> ·
                <form method="post" style="display:inline" onsubmit="return confirm('Artikel wirklich löschen?');">
                  <?= csrf_field() ?>
                  <input type="hidden" name="action" value="delete_article">
                  <input type="hidden" name="id" value="<?= $a['id'] ?>">
                  <button type="submit" style="background:none;border:none;color:#dc2626;cursor:pointer;padding:0;font-size:.9rem">Löschen</button>
                </form>
              </td>
            </tr>
          <?php endforeach; ?>
        </tbody>
      </table>
    </div>
  </div>

  <div style="flex:1; min-width:260px">
    <div class="card">
      <h3>Kategorien</h3>
      <?php foreach ($categories as $c): ?>
        <div style="display:flex; justify-content:space-between; align-items:center; padding:6px 0; border-bottom:1px solid var(--border)">
          <span><?= e($c['name']) ?></span>
          <form method="post" onsubmit="return confirm('Kategorie wirklich löschen?');">
            <?= csrf_field() ?>
            <input type="hidden" name="action" value="delete_category">
            <input type="hidden" name="id" value="<?= $c['id'] ?>">
            <button type="submit" style="background:none;border:none;color:#dc2626;cursor:pointer;padding:0;font-size:.85rem">Löschen</button>
          </form>
        </div>
      <?php endforeach; ?>
      <form method="post" style="margin-top:14px">
        <?= csrf_field() ?>
        <input type="hidden" name="action" value="create_category">
        <label for="name">Neue Kategorie</label>
        <input type="text" id="name" name="name" required>
        <div class="btn-row"><button type="submit" class="btn secondary">Hinzufügen</button></div>
      </form>
    </div>
  </div>
</div>

<?php require __DIR__ . '/_footer.php'; ?>