<?php
require_once __DIR__ . '/../includes/bootstrap.php';
$staff = require_admin_or_permission('manage_problems');
$pdo = get_db();
$errors = [];
$problemId = (int) ($_GET['id'] ?? $_POST['problem_id'] ?? 0);
$activeTab = (string) ($_GET['tab'] ?? 'list');
if (!in_array($activeTab, ['list', 'create'], true)) $activeTab = 'list';

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    verify_csrf();
    $action = (string) ($_POST['action'] ?? '');
    $activeTab = $action === 'problem_create' ? 'create' : 'list';
    try {
        if ($action === 'problem_create') {
            $pdo->beginTransaction();
            $problemId = ticket_problem_create($pdo, $_POST, (int) $staff['id']);
            $ticketNumber = trim((string) ($_POST['ticket_number'] ?? ''));
            if ($ticketNumber !== '') {
                $ticketStmt = $pdo->prepare('SELECT id FROM tickets WHERE ticket_number = ?');
                $ticketStmt->execute([$ticketNumber]);
                $ticketId = (int) $ticketStmt->fetchColumn();
                if (!$ticketId) throw new InvalidArgumentException('Das angegebene Ticket wurde nicht gefunden.');
                ticket_problem_link($pdo, $problemId, $ticketId, (int) $staff['id']);
                log_activity($pdo, $ticketId, (int) $staff['id'], 'Mit ' . ticket_problem_number($problemId) . ' verknüpft');
            }
            $pdo->commit();
            audit_log($staff['id'], 'Problem ' . ticket_problem_number($problemId) . ' erstellt');
            flash('success', ticket_problem_number($problemId) . ' wurde angelegt.');
            redirect('/staff/problems.php?tab=list&id=' . $problemId);
        } elseif ($action === 'problem_update') {
            if (!ticket_problem_update($pdo, $problemId, $_POST, (int) $staff['id'])) throw new InvalidArgumentException('Problem nicht gefunden.');
            audit_log($staff['id'], 'Problem ' . ticket_problem_number($problemId) . ' aktualisiert');
            flash('success', 'Problem wurde gespeichert.');
        } elseif ($action === 'ticket_link') {
            $ticketNumber = trim((string) ($_POST['ticket_number'] ?? ''));
            $ticketStmt = $pdo->prepare('SELECT id FROM tickets WHERE ticket_number = ?');
            $ticketStmt->execute([$ticketNumber]);
            $ticketId = (int) $ticketStmt->fetchColumn();
            if (!$ticketId) throw new InvalidArgumentException('Das angegebene Ticket wurde nicht gefunden.');
            if (!ticket_problem_link($pdo, $problemId, $ticketId, (int) $staff['id'])) throw new InvalidArgumentException('Ticket oder Problem wurde nicht gefunden.');
            log_activity($pdo, $ticketId, (int) $staff['id'], 'Mit ' . ticket_problem_number($problemId) . ' verknüpft');
            audit_log($staff['id'], 'Ticket mit ' . ticket_problem_number($problemId) . ' verknüpft');
            flash('success', 'Ticket wurde mit dem Problem verknüpft.');
        } elseif ($action === 'ticket_unlink') {
            $ticketId = (int) ($_POST['ticket_id'] ?? 0);
            if (!ticket_problem_unlink($pdo, $problemId, $ticketId)) throw new InvalidArgumentException('Dieses Ticket ist mit dem Problem nicht verknüpft.');
            log_activity($pdo, $ticketId, (int) $staff['id'], 'Verknüpfung mit ' . ticket_problem_number($problemId) . ' entfernt');
            audit_log($staff['id'], 'Ticket von ' . ticket_problem_number($problemId) . ' getrennt');
            flash('success', 'Ticket-Verknüpfung wurde entfernt.');
        }
    } catch (Throwable $e) {
        if ($pdo->inTransaction()) $pdo->rollBack();
        $errors[] = $e instanceof InvalidArgumentException ? $e->getMessage() : 'Änderung konnte nicht gespeichert werden.';
    }
    if (!$errors) redirect('/staff/problems.php' . ($problemId ? '?id=' . $problemId : ''));
}

$problems = ticket_problems($pdo);
$problem = $problemId ? ticket_problem_get($pdo, $problemId) : null;
if ($problemId && !$problem) $errors[] = 'Problem nicht gefunden.';
$linkedTickets = $problem ? ticket_problem_tickets($pdo, $problemId) : [];
$problemStatuses = ticket_problem_statuses();
$activePage = 'problems';
$pageTitle = 'Problemmanagement';
require __DIR__ . '/_header.php';
?>
<div class="pm-head">
  <div>
    <h1 style="margin:0">Problemmanagement</h1>
    <p class="muted" style="margin:4px 0 0">Bündeln Sie Tickets mit derselben Ursache. Ursache, Workaround und dauerhafte Lösung werden zentral dokumentiert.</p>
  </div>
  <?php if ($activeTab === 'create' || $problem): ?>
    <a class="btn secondary" href="/staff/problems.php">← Alle Probleme</a>
  <?php else: ?>
    <a class="btn" href="/staff/problems.php?tab=create">+ Neues Problem</a>
  <?php endif; ?>
</div>
<?php foreach ($errors as $error): ?><div class="flash error"><?= e($error) ?></div><?php endforeach; ?>
<?php if ($activeTab === 'create'): ?>
<section class="card">
  <h2 style="margin-top:0">Neues Problem erfassen</h2>
  <p class="muted">Titel und erste Ticketnummer eintragen. Ursache und dauerhafte L&#246;sung k&#246;nnen danach erg&#228;nzt werden.</p>
  <form method="post"><?= csrf_field() ?><input type="hidden" name="action" value="problem_create">
    <label for="new_problem_title">Titel</label><input id="new_problem_title" type="text" name="title" maxlength="200" required placeholder="Kurze Problembeschreibung">
    <label for="new_problem_ticket" style="margin-top:8px">Ticket verkn&#252;pfen (optional)</label><input id="new_problem_ticket" type="text" name="ticket_number" placeholder="Ticketnummer">
    <label for="new_problem_description" style="margin-top:8px">Beschreibung / Auswirkungen</label><textarea id="new_problem_description" name="description" rows="3"></textarea>
    <label for="new_problem_cause" style="margin-top:8px">Ursache (falls bekannt)</label><textarea id="new_problem_cause" name="root_cause" rows="3"></textarea>
    <label for="new_problem_workaround" style="margin-top:8px">Workaround (optional)</label><textarea id="new_problem_workaround" name="workaround" rows="3"></textarea>
    <button class="btn" type="submit" style="margin-top:12px">Problem anlegen</button>
  </form>
</section>
<?php else: ?>
<?php if (!$problem): ?>
  <?php $openCount = 0; foreach ($problems as $item) { if ($item['status'] !== 'resolved') $openCount++; } ?>
  <section class="card" style="padding:0;overflow:hidden">
    <?php if (!$problems): ?>
      <div class="empty-state" style="padding:32px">Noch keine Probleme erfasst. <a href="/staff/problems.php?tab=create">Erstes Problem anlegen</a></div>
    <?php else: ?>
    <div class="muted" style="padding:14px 20px;border-bottom:1px solid var(--border,#e3e9ee)"><?= count($problems) ?> Probleme · <?= $openCount ?> offen</div>
    <table>
      <thead><tr><th>Nr.</th><th>Titel</th><th>Status</th><th>Tickets</th><th>Zuletzt geändert</th></tr></thead>
      <tbody>
      <?php foreach ($problems as $item):
        $pColor = ['investigating' => '#dc2626', 'workaround' => '#d97706', 'monitoring' => '#2563eb', 'resolved' => '#16a34a'][$item['status']] ?? '#64748b';
        $pUrl = '/staff/problems.php?id=' . (int) $item['id'];
      ?>
        <tr>
          <td style="white-space:nowrap"><a href="<?= $pUrl ?>" class="ticket-no"><?= e(ticket_problem_number((int) $item['id'])) ?></a></td>
          <td><a href="<?= $pUrl ?>"><strong><?= e($item['title']) ?></strong></a>
            <?php if (!empty($item['description'])): ?><div class="muted" style="font-size:.8rem;max-width:560px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap"><?= e($item['description']) ?></div><?php endif; ?></td>
          <td><span class="badge" style="background:<?= $pColor ?>"><?= e($problemStatuses[$item['status']] ?? $item['status']) ?></span></td>
          <td><?= (int) $item['ticket_count'] ?></td>
          <td class="muted" style="white-space:nowrap"><?= e(format_dt((string) ($item['updated_at'] ?? $item['created_at']))) ?></td>
        </tr>
      <?php endforeach; ?>
      </tbody>
    </table>
    <?php endif; ?>
  </section>
<?php else: ?>
  <div class="pm-detail">
  <main>
    <section class="card">
      <div style="display:flex;justify-content:space-between;align-items:start;gap:12px;flex-wrap:wrap">
        <div><span class="muted"><?= e(ticket_problem_number($problemId)) ?></span><h2 style="margin:2px 0 12px"><?= e($problem['title']) ?></h2></div>
        <span class="muted">Erstellt <?= e(format_dt((string) $problem['created_at'])) ?><?= $problem['creator_name'] ? ' von ' . e($problem['creator_name']) : '' ?></span>
      </div>
      <form method="post"><?= csrf_field() ?><input type="hidden" name="action" value="problem_update"><input type="hidden" name="problem_id" value="<?= $problemId ?>">
        <label for="problem_title">Titel</label><input id="problem_title" type="text" name="title" maxlength="200" required value="<?= e($problem['title']) ?>">
        <label for="problem_description" style="margin-top:8px">Beschreibung / Auswirkungen</label><textarea id="problem_description" name="description" rows="3"><?= e((string) ($problem['description'] ?? '')) ?></textarea>
        <label for="problem_root_cause" style="margin-top:8px">Ursache</label><textarea id="problem_root_cause" name="root_cause" rows="3"><?= e((string) ($problem['root_cause'] ?? '')) ?></textarea>
        <label for="problem_workaround" style="margin-top:8px">Workaround</label><textarea id="problem_workaround" name="workaround" rows="3"><?= e((string) ($problem['workaround'] ?? '')) ?></textarea>
        <label for="problem_resolution" style="margin-top:8px">Dauerhafte Lösung</label><textarea id="problem_resolution" name="resolution" rows="3"><?= e((string) ($problem['resolution'] ?? '')) ?></textarea>
        <div style="display:flex;gap:12px;align-items:end;flex-wrap:wrap;margin-top:8px"><div><label for="problem_status">Status</label><select id="problem_status" name="status"><?php foreach ($problemStatuses as $key => $label): ?><option value="<?= e($key) ?>" <?= $problem['status'] === $key ? 'selected' : '' ?>><?= e($label) ?></option><?php endforeach; ?></select></div><button class="btn" type="submit">Problem speichern</button></div>
      </form>
    </section>
  </main>
  <aside>
    <section class="card">
      <h3 style="margin-top:0">Verknüpfte Tickets (<?= count($linkedTickets) ?>)</h3>
      <form method="post" style="display:flex;gap:8px;flex-wrap:wrap;align-items:end;margin-bottom:12px"><?= csrf_field() ?><input type="hidden" name="action" value="ticket_link"><input type="hidden" name="problem_id" value="<?= $problemId ?>"><div style="flex:1;min-width:200px"><label for="link_ticket_number">Ticketnummer</label><input id="link_ticket_number" type="text" name="ticket_number" required placeholder="z. B. 260001"></div><button class="btn secondary" type="submit">Ticket verknüpfen</button></form>
      <?php if (!$linkedTickets): ?><p class="muted">Noch keine Tickets mit diesem Problem verknüpft.</p><?php endif; ?>
      <?php foreach ($linkedTickets as $linked): ?>
        <div style="display:flex;justify-content:space-between;gap:10px;align-items:center;border-top:1px solid var(--border,#e3e9ee);padding:9px 0">
          <div><a href="/staff/ticket_view.php?n=<?= urlencode((string) $linked['ticket_number']) ?>"><strong>#<?= e($linked['ticket_number']) ?></strong> · <?= e($linked['subject']) ?></a><div class="muted" style="font-size:.78rem"><?= e($linked['requester_name']) ?> · <?= e(status_label((string) $linked['status'])[0]) ?></div></div>
          <form method="post" onsubmit="return confirm('Ticket-Verknüpfung entfernen?')"><?= csrf_field() ?><input type="hidden" name="action" value="ticket_unlink"><input type="hidden" name="problem_id" value="<?= $problemId ?>"><input type="hidden" name="ticket_id" value="<?= (int) $linked['id'] ?>"><button class="btn secondary" type="submit">Trennen</button></form>
        </div>
      <?php endforeach; ?>
    </section>
  </aside>
  </div>
<?php endif; ?>
<?php endif; ?>
<style>
.pm-head{display:flex;justify-content:space-between;align-items:flex-start;gap:16px;flex-wrap:wrap;margin-bottom:18px}
.pm-detail{display:grid;grid-template-columns:minmax(0,1fr) minmax(280px,400px);gap:16px;align-items:start}
@media(max-width:900px){.pm-detail{grid-template-columns:1fr}}
</style>
<?php require __DIR__ . '/_footer.php'; ?>