<?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.
 */

// Prevent hack attempts..
if (!defined('ASHITA_PSCAPI')) { exit; }

/**
 * Generates a JSON response object.
 * 
 * @param {number} $errorc - The error code of the response.
 * @param {string} $errorm - The error message of the response.
 * @return {$string} A JSON formatted object of the error information.
 */
function generateErrorResponse($errorc, $errorm)
{
    $err = "{ ";
    $err .= "\"status\": 1,";
    $err .= "\"errorc\": " . $errorc;
    $err .= "\"errorm\": " . $errorm;
    $err .= "}";
    return $err;
}

/**
 * Checks if the given configuration object is valid.
 * 
 * @param {object} $config - The configuration object to validate.
 * @return {bool} True on success, false otherwise.
 */
function isValidConfiguration($config)
{
    // Ensure the configuration arrays are valid and exist..
    if (!is_array($config) ||
        !array_key_exists('db', $config) || !is_array($config['db']) ||
        !array_key_exists('cache', $config) || !is_array($config['cache']) ||
        !array_key_exists('server', $config) || !is_array($config['server']))
    {
        return false;
    }

    // Validate the database configurations..
    if (!array_key_exists('host', $config['db']) || !is_string($config['db']['host']) ||
        !array_key_exists('port', $config['db']) || !is_string($config['db']['port']) ||
        !array_key_exists('user', $config['db']) || !is_string($config['db']['user']) ||
        !array_key_exists('pass', $config['db']) || !is_string($config['db']['pass']) ||
        !array_key_exists('name', $config['db']) || !is_string($config['db']['name']))
    {
        return false;
    }

    // Validate the cache configurations..
    if (!array_key_exists('lifetime', $config['cache']) || !is_numeric($config['cache']['lifetime']))
    {
        return false;
    }

    // Validate the server configurations..
    if (!array_key_exists('lifetime', $config['server']) || !is_numeric($config['server']['lifetime']) ||
        !array_key_exists('name', $config['server']) || !is_string($config['server']['name']) ||
        !array_key_exists('levelcap', $config['server']) || !is_numeric($config['server']['levelcap']) ||
        !array_key_exists('ip', $config['server']) || !is_string($config['server']['ip']) ||
        !array_key_exists('website', $config['server']) || !is_string($config['server']['website']) ||
        !array_key_exists('discord', $config['server']) || !is_string($config['server']['discord']))
    {
        return false;
    }
    
    return true;
}

/**
 * Checks if the given cache data is valid.
 * 
 * @param {object} $data - The cache object to validate.
 * @return {bool} True on success, false otherwise.
 */
function isValidCachedFile($data)
{
    // Ensure the incoming object is valid..
    if (!$data || $data === null || !is_object($data)) { return false; }

    // Check for the required data entries of the cached data..
    if (!isset($data->status) || !is_numeric($data->status) || $data->status !== 0) { return false; }
    if (!isset($data->version) || !is_string($data->version)) { return false; }
    if (!isset($data->lifetime) || !is_numeric($data->lifetime)) { return false; }
    if (!isset($data->timestamp) || !is_numeric($data->timestamp)) { return false; }
    if (!isset($data->name) || !is_string($data->name)) { return false; }
    if (!isset($data->levelcap) || !is_numeric($data->levelcap)) { return false; }
    if (!isset($data->ip) || !is_string($data->ip)) { return false; }
    if (!isset($data->website) || !is_string($data->website)) { return false; }
    if (!isset($data->discord) || !is_string($data->discord)) { return false; }
    if (!isset($data->total) || !is_numeric($data->total)) { return false; }
    if (!isset($data->unique) || !is_numeric($data->unique)) { return false; }

    return true;
}

/**
 * Obtains the cached data from the given file.
 * 
 * @param {string} $file - The file path to the cache data to obtain.
 * @return {bool|string} False if invalid or not found, string of the cached data if found and valid.
 */
function getCachedData($file)
{
    // Ensure the cache file exists..
    if (!file_exists($file)) { return false; }

    try
    {
        // Open the cache file for reading..
        $f = fopen($file, "r");
        if ($f === FALSE) { return false; }

        // Read the cached file contents..
        $cache = fread($f, filesize($file));
        fclose($f);

        // Parse the file data as json..
        $data = json_decode($cache);
        if (json_last_error() !== JSON_ERROR_NONE) { return false; }

        // Validate the cache file..
        if (!isValidCachedFile($data)) { return false; }

        // Cache is valid, return it..
        return $cache;
    }
    catch (Exception $e)
    {
        return false;
    }
}