<?php

/**
 * Ashita Private Server Collection API - Copyright (c) 2018 atom0s [atom0s@live.com]
 *
 * This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
 * To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/4.0/ or send a letter to
 * Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.
 *
 * By using this script, you agree to the above license and its terms.
 *
 *      Attribution - You must give appropriate credit, provide a link to the license and indicate if changes were
 *                    made. You must do so in any reasonable manner, but not in any way that suggests the licensor
 *                    endorses you or your use.
 *
 *   Non-Commercial - You may not use the material (this script) for commercial purposes.
 *
 *   No-Derivatives - If you remix, transform, or build upon the material (this script), you may not distribute the
 *                    modified material. You are, however, allowed to submit the modified works back to the original
 *                    Ashita Private Server Collection API project in attempt to have it added to the original project.
 *
 * You may not apply legal terms or technological measures that legally restrict others
 * from doing anything the license permits.
 *
 * You may contact me, atom0s, at atom0s@live.com for more information or if you are seeking commercial use.
 *
 * No warranties are given.
 */

// Define the script globals..
define('ASHITA_PSCAPI', true);
define('ASHITA_PSCAPI_VERSION', '1');

// Prepare needed variables and includes..
$ashita_root_path = './';
$phpEx = substr(strrchr(__FILE__, '.'), 1);
require($ashita_root_path . 'config.' . $phpEx);
require($ashita_root_path . 'ashita.functions.' . $phpEx);
$cacheFile = $ashita_root_path . 'cache.json';

/**
 * Generates a timestamp used to determine the time the script was ran to compare
 * against the current cache data. Offset is based on Los Angeles so that all servers
 * cached information updates are on the same time schedule.
 */
$date = new DateTime(null, new DateTimeZone('America/Los_Angeles'));
$timestamp = $date->getTimestamp();

// Ensure the configuration file is valid..
if (!isValidConfiguration($config))
{
    echo generateErrorResponse(0x80000001, "Invalid configuration file detected.");
    exit;
}

// Attempt to get the cached data..
$data = getCachedData($cacheFile);
if ($data !== false)
{
    // Check if the cached data has expired..
    if (json_decode($data)->timestamp + $config['cache']['lifetime'] > $timestamp)
    {
        // Erase configurations from memory..
        unset($config);

        // Data is still valid, use it..
        echo $data;
        exit;
    }
}

/**
 * No cached data present or it is invalid or expired. Instead, we must query the 
 * database for the needed information to populate the cache with new data.
 */
try
{
    // Connect to the database..
    $db = new PDO("mysql:host={$config['db']['host']};port={$config['db']['port']};dbname={$config['db']['name']}", $config['db']['user'], $config['db']['pass']);
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    
    // Empty the database configurations..
    unset($config['db']);

    // Query the database for the current online counts..
    $sql = $db->query("SELECT COUNT(DISTINCT(client_addr)) AS u, COUNT(*) AS t FROM accounts_sessions;")->fetchall();
    if (!is_array($sql) || count($sql) !== 1)
    {
        // Invalid results, return an error..
        echo generateErrorResponse(0x80000002, 'Failed to query database for count information.');
        exit;
    }

    // Build the new server information array..
    $data = array(
        'status'    => 0,
        'version'   => ASHITA_PSCAPI_VERSION,
        'timestamp' => $timestamp,
        'lifetime'  => $config['server']['lifetime'],
        'name'      => $config['server']['name'],
        'levelcap'  => $config['server']['levelcap'],
        'ip'        => $config['server']['ip'],
        'website'   => $config['server']['website'],
        'discord'   => $config['server']['discord'],
        'total'     => $sql[0]['t'],
        'unique'    => $sql[0]['u']
    );

    try
    {
        // Open the cache file for writing..
        $f = fopen($cacheFile, 'w');
        if ($f === FALSE)
        {
            echo generateErrorResponse(0x80000003, 'Failed to update cache file. (1)');
            exit;
        }

        // Write the data to the cache file..
        fwrite($f, json_encode($data));
        fclose($f);
    }
    catch (Exception $e)
    {
        echo generateErrorResponse(0x80000003, 'Failed to update cache file. (2)');
        exit;
    }

    // Cleanup the pdo objects..
    $sql = null;
    $db = null;

    // Echo the new data..
    echo json_encode($data);
    exit;
}
catch (Exception $e)
{
    echo generateErrorResponse(0x80000004, 'Failed to get server information.');
    exit;
}