<?php
$user_id = require_auth();

// GET /api/decks
if (get_method() === 'GET' && empty($segments[1])) {
    $stmt = $pdo->prepare("
        SELECT d.id, d.slug, d.name, d.description, d.card_count,
            COUNT(cp.id) AS reviewed,
            COUNT(cp.id) FILTER (WHERE cp.last_rating IN ('easy','medium')) AS correct,
            COUNT(cp.id) FILTER (WHERE cp.next_review <= CURRENT_DATE) AS due
        FROM decks d
        LEFT JOIN cards c ON c.deck_id = d.id
        LEFT JOIN card_progress cp ON cp.card_id = c.id AND cp.user_id = :uid
        GROUP BY d.id
        ORDER BY d.sort_order, d.name
    ");
    $stmt->execute([':uid' => $user_id]);
    json_ok(['decks' => $stmt->fetchAll()]);
}

// GET /api/decks/{slug}
if (get_method() === 'GET' && !empty($segments[1])) {
    $stmt = $pdo->prepare("SELECT * FROM decks WHERE slug = :s");
    $stmt->execute([':s' => $segments[1]]);
    $deck = $stmt->fetch();
    if (!$deck) json_error('Deck nicht gefunden', 404);
    json_ok(['deck' => $deck]);
}

json_error('Methode nicht erlaubt', 405);