<?php

### version 2024-30-08 ###

// Note on this API.
// This file when implementation is provided should be placed under /admin/cdn folder.
// All functions in this file should be prefixed with filename.
// For example if filename is ucdn.php, functions should be renamed to ucdn_get_file() and etc.

/**
 * Tests if API works correctly.
 *
 * @param $streaming_key   [String]   protection key entered in storage server configuration, example: abcdefg
 * @return null on success, error message / code on failure
 */

function ahcdn_test($streaming_key)
{
    // return success by default
    return null;
}

/**
 * Returns video file URL with all parameters configured.
 *
 * @param $file_path       [String]    relative file path, example: 2000/2122/2122.flv
 * @param $file_url        [String]    full file URL, example: http://cdn.domain.com/contents/videos/2000/2122/2122.flv
 * @param $start_str       [String]    video streaming offset value with parameter name, can be null, example: start=123
 * @param $limit           [Integer]   download speed limit in kilobits per second (0 means no limit), example: 100
 * @param $streaming_key   [String]    protection key entered in storage server configuration, example: abcdefg
 * @return video file URL
 */
function ahcdn_get_video($file_path, $file_url, $start_str, $limit, $streaming_key)
{
    require 'ahcdn_config.php';

    if (isset($_SERVER['SERVER_NAME'])) {
        if (isset($do_no_redirect[$_SERVER['SERVER_NAME']])) {
            if ($start_str <> '') {
                return "$file_url?$start_str";
            }
            return $file_url;
        }
    }

    $CC = $_SERVER['GEOIP_COUNTRY_CODE'];

    if (isset($post_re) and !empty($post_re)) {
        $file_path = preg_replace($post_re[0], $post_re[1], $file_path);
    }

    ### check alternative redirects
    ### checks full file path ($file_url without domain part) for match mask_re and changes KVS domain to alternative
    $file_url_without_domain = explode('/', $file_url, 4)[3];  # this gives contents/videos/2000/2122/2122.flv
    if (isset($alt_redirect) && is_array($alt_redirect)) {
        for ($i = 0; $i < count($alt_redirect); ++$i) {
            if (isset($alt_redirect[$i]['file_url_re'])) {
                if (preg_match("/" . $alt_redirect[$i]['file_url_re'] . "/", $file_url)) {
                    if (isset($alt_redirect[$i]['mask_re']) && isset($alt_redirect[$i]['url']) && preg_match("/" . $alt_redirect[$i]['mask_re'] . "/", $file_url_without_domain)) {
                        ahcdn_log(2, "$CC : " . $alt_redirect[$i]['url'] . "/" . $file_url_without_domain . "\n");
                        return $alt_redirect[$i]['url'] . "/" . $file_url_without_domain;
                    }
                }
            } else {
                if (isset($alt_redirect[$i]['mask_re']) && isset($alt_redirect[$i]['url']) && preg_match("/" . $alt_redirect[$i]['mask_re'] . "/", $file_url_without_domain)) {
                    ahcdn_log(2, "$CC : " . $alt_redirect[$i]['url'] . "/" . $file_url_without_domain . "\n");
                    return $alt_redirect[$i]['url'] . "/" . $file_url_without_domain;
                }
            }
        }
    }

    $time = time() + (isset($expire) && $expire ? $expire : 3600);          # key will expire in 1 hour
    $url = ',end=' . $time;
    if (isset($ip_limit) && $ip_limit) {
        if ($ip_limit < 1) {
            $ip_limit = 1;
        };
        if ($ip_limit > 5) {
            $ip_limit = 5;
        };
        $url .= ',limit=' . $ip_limit;
    };
    if (isset($lock_ip) && $lock_ip) {
        $url .= ',ip=' . ahcdn_get_ip();
    }
    if (isset($ip_limit) && $ip_limit) {
        $url .= '/data=' . ahcdn_generate_random_string();
    }

    if (isset($geo_specific[$CC]['bitrate']) && $geo_specific[$CC]['bitrate']) {
        $bitrate = $geo_specific[$CC]['bitrate'];
    }
    if (isset($geo_specific[$CC]['buffer']) && $geo_specific[$CC]['buffer']) {
        $buffer = $geo_specific[$CC]['buffer'];
    }
    if (isset($referer)) {
        $url .= '/referer=' . $referer;
    }
    ### limits ###
    if (isset($use_kvs_limit) && $use_kvs_limit) {
        if ($limit > 0) {
            $limit = round($limit / 8, 2);
            $url .= '/speed=' . $limit . 'K';
        }
    } else {
        if (isset($bitrate) && $bitrate) {
            $url .= '/speed=' . $bitrate;
        }
    }
    if (isset($buffer) && $buffer) {
        $url .= '/buffer=' . $buffer;
    }

    ### check download ###
    if (isset($_GET['download'])) {
        $is_download = trim($_GET['download']);
        if ($is_download == 'true') {
            $url .= '/download2=';
        };
    }
    if (isset($_GET['download_filename'])) {
        $download_filename = trim($_GET['download_filename']);
        $url .= $download_filename;
    }

    $url .= '/' . ltrim($file_path, '/');

    $key = substr(base64_encode(md5("$secret$url", true)), 0, 22);
    $key = str_replace('/', '-', $key);

    if (!isset($domain)) {
        # if $domain is not set in ahcdn_config.php  read it from $file_url (URL(*) field)
        $split_arr = preg_split("/\//", $file_url);
        $domain = $split_arr[0] . '/' . $split_arr[1] . '/' . $split_arr[2];
    }

    if (preg_match('/^http/', $domain)) {
        $fullurl = $domain . '/key=' . $key . $url;
    } else {
        $fullurl = 'http://' . $domain . '/key=' . $key . $url;
    }

    if ($start_str <> '') {
        $fullurl .= '?' . $start_str;
    }
    ahcdn_log(2, "$CC : $fullurl \n");
    return $fullurl;
}

/**
 * Returns image / zip file URL with all parameters configured.
 *
 * @param $file_path       [String]   relative file path, example: main/800x600/2000/2122/10982.jpg
 * @param $file_url        [String]   full file URL, example: http://cdn.domain.com/contents/albums/main/800x600/2000/2122/10982.jpg
 * @param $streaming_key   [String]   protection key entered in storage server configuration, example: abcdefg
 * @return image / zip file URL
 */

function ahcdn_get_image($file_path, $file_url, $streaming_key)
{
    // example is to return URL without any parameters
    return $file_url;
}


/**
 * Invalidates the given folders or files on CDN.
 * Files are always provided as exact list of all affected files. Folders are provided in some cases where all files
 * in specific folders should be invalidated.
 *
 * Folders and files contain paths relative to the given $server_url.
 *
 * @param $server_url [String] CDN URL configured in storage server, example: http://cdn.domain.com/contents/videos
 * @param $folders [Array of String] list of related folder paths, which should be invalidated, can be null, example: array("2000/2122", "2000/2123")
 * @param $files [Array of String] list of related file paths, which should be invalidated, example: array("2000/2122/2122.flv", "2000/2122/2122.mp4", "2000/2123/2123.flv", "2000/2123/2123.mp4")
 * @param $operation [String] indicates operation on the above files, one if the following: "add", "change", "delete", "multiple"
 * (multiple means that KVS cannot exactly tell operation, part of files may be updated and part deleted and etc.)
 */
function ahcdn_invalidate_resources($server_url, $folders, $files, $operation)
{

    require 'ahcdn_config.php';
    if (isset($disable_cdn_api) and ($disable_cdn_api > 0)) {
        return true;
    }

    if (!isset($api_user) || empty($api_user) || !isset($api_password) || empty($api_password)) {
        $error = "No API auth data in config!";
        return $error;
    }

    if (empty($files) and empty($folders)) {
        $error = "Nothing to do!";
        return $error;
    }

    if (empty($folders)) {
        $folders = array();
    } else {
        if (is_string($folders)) {
            $folders = array($folders);
        }
    }

    if (empty($files)) {
        $files = array();
    } else {
        if (is_string($files)) {
            $files = array($files);
        }
    }

    $real_folders = array();
    $real_files = array();

    foreach ($folders as $folder) {
        $folder = trim($folder, '/');
        $real_folders[] = $folder; #$server_url.$folder.'/*';
    }

    foreach ($files as $file) {
        $file = ltrim($file, '/');
        if (isset($post_re) and !empty($post_re)) {
            $file = preg_replace($post_re[0], $post_re[1], $file);
        }
        if (isset($prefix) and !empty($prefix)) {
            $real_files[] = $prefix . $file;
        } else {
            $real_files[] = $file;
        }
    }

    $names = implode("\n", $real_files);
    if (isset($operation) and ($operation == 'delete' or $operation == 'change')) {
        if (isset($ignore_change_invalidate) and ($ignore_change_invalidate == 1) and ($operation == 'change')) {
            # do not send delete api call 
            ahcdn_log(1, "Ignore 'change' operation on invalidate_resources(ignore_change_invalidate is set to 1) : files = '$names' \n");
            return true;
        }
        $names = implode("\n", $real_files);
        $idata = array('names' => $names);
        $post_data = http_build_query($idata);
        $r = array();
        $r = ahcdn_api_call($api_user, $api_password, 'cp.ahcdn.com/api2/file/delete', $post_data);
        ahcdn_log(1, "'$operation' operation on invalidate_resources  : files = '$names' :: code = " . $r['response_code'] . " :: response = " . $r['response_text'] . "\n");
        if ($r['response_code'] == 200) {
            return true;
        }
        return false;
    } elseif (isset($operation) and ($operation == 'add' or $operation == 'multiple')) {
        // Can not add/change files without their sizes
        ahcdn_log(1, "ADD/MULTIPLE operation on invalidate_resources : operation = '$operation' :: files = '$names'\n");
    } else {
        $names = implode("\n", $real_files);
        $idata = array('names' => $names);
        $post_data = http_build_query($idata);
        ahcdn_log(1, "unknown operation on invalidate_resources, treating as delete on old KVS : operation = '$operation' :: files = '$names'\n");
        $r = array();
        $r = ahcdn_api_call($api_user, $api_password, 'cp.ahcdn.com/api2/file/delete', $post_data);
        ahcdn_log(1, "DELETE operation on invalidate_resources  : files = '$names' :: code = " . $r['response_code'] . " :: response = " . $r['response_text'] . "\n");
        if ($r['response_code'] == 200) {
            return true;
        }
        return false;
    }
}

function ahcdn_api_call($api_user, $api_password, $api_url, $post_data)
{
    if (!function_exists('curl_init')) {
        $response = 'No PHP-CURL found. ' .
            'See http://php.net/manual/en/curl.installation.php';
        return false;
    }
    $ch = curl_init();
    curl_setopt_array(
        $ch,
        array(
            CURLOPT_URL => 'https://' . $api_url . '?' . $post_data,
            CURLOPT_PORT => 443,
            CURLOPT_SSL_VERIFYPEER => 0,
            CURLOPT_HEADER => 0,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FORBID_REUSE => 1,      // no caching
            CURLOPT_FRESH_CONNECT => 1,     // no caching  
            CURLOPT_CUSTOMREQUEST => 'POST',
            CURLOPT_USERPWD => $api_user . ":" . $api_password
        )
    );
    $response_text = curl_exec($ch);
    $response_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);
    $r = array();
    $r['response_code'] = $response_code;
    $r['response_text'] = $response_text;
    return $r;
}

function ahcdn_log($l_level, $string)
{
    require 'ahcdn_config.php';
    if (!isset($log_level)) {
        $log_level = 1;
    }
    if (isset($log_file)) {
        if (($log_level > 0) and ($l_level <= $log_level)) {
            if (file_exists($log_file)) {
                $h = fopen($log_file, "a");
                fwrite($h, date(DATE_RFC2822) . " : " . $string);
                fclose($h);
            }
        }
    }
}

function ahcdn_get_ip()
{
    if (getenv("REMOTE_ADDR")) {
        return getenv("REMOTE_ADDR");
    } elseif (getenv("HTTP_CLIENT_IP")) {
        return getenv("HTTP_CLIENT_IP");
    }
    return '';
}

function ahcdn_generate_random_string()
{
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < 6; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }
    return $randomString;
}

?>