<?php

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

requireLogin();

header('Content-Type: application/json');

$user = $_SESSION['user'];

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

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

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

$words = sortDueWords($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;
}

$word = array_values($due)[0];

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