<?php

require_once __DIR__ . '/../includes/config.php';
require_once __DIR__ . '/../includes/functions.php';
require_once __DIR__ . '/../includes/jsondb.php';
require_once __DIR__ . '/../includes/srs_queue.php';
require_once __DIR__ . '/../includes/auth.php';

requireLogin();

header('Content-Type: application/json; charset=utf-8');

$user = $_SESSION['user'];

$lang = $_GET['lang'] ?? '';
$list = $_GET['list'] ?? '';

$file = listPath($user, $lang, $list);
$data = JsonDB::read($file);

if (!isset($data['words']) || !is_array($data['words'])) {
    echo json_encode(['error' => 'list_not_found']);
    exit;
}

$words = $data['words'];

$today = date('Y-m-d');

$due = array_filter($words, function ($w) use ($today) {
    return !isset($w['nextReview']) || $w['nextReview'] <= $today;
});

if (count($due) === 0) {
    $due = $words;
}

// pak altijd eerste uit gesorteerde set (stabiel gedrag)
$due = array_values($due);

$word = $due[0];

echo json_encode([
    'word' => $word
]);