<?php
/**
 * 获取慕课网某个课程的列表章节
 */

/**
 * 获取列表
 * @param $url
 * @param $is_title
 * @return array
 * @throws Exception
 */
function GetList($url, $is_title)
{
    if (empty($url)) {
        throw new Exception('链接为空');
    }

    $content = file_get_contents($url);
    $pattern = '/<i\sclass="imv2-play_circle\stype"><\/i\>\s+(.*)\n/';
    preg_match_all($pattern, $content, $res);

    $res = isset($res[1]) ? $res[1] : '';

    if (empty($res)) {
        throw new Exception('获取不到当前页面的列表');
    }

    $result = [];

    // 对字符串进行去除首尾空白符以及加上markdown的标题
    foreach ($res as $key => $value) {
        if ($is_title) {
            $result[] = '## ' . trim($value);
        } else {
            $result[] = trim($value);
        }
    }

    return $result;
}

try {
    $url = trim($_POST['url']);
    $is_title = intval($_POST['is_title']);
    $is_title = $is_title == 0 ? 0 : 1;
    $result = GetList($url, $is_title);

    $result = [
        'data'   => $result,
        'status' => 1
    ];
    echo json_encode($result);
    exit();
} catch (Exception $e) {
    echo json_encode(['data' => $e->getMessage(), 'status' => 0]);
    exit();
}