/**
 * 微信接口调用
 * 依赖
 * 全局变量
 * global $uid 公众号用户id, $wid 公众号id, $wechatid 粉丝唯一id;
 * 参数
 * $postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
 * $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
 * 缓存类 自定义
 * Cache:set
 * Cache:get
 * 具体业务修改
 * 1.上传图文信息至微信素材库
 * function uploadArticlesToWeiXinServer()
 * 2.关键字匹配图文回复
 * function getArticleData()
 * 
 * usage:
 * $options = array(
 * 'token'=>'tokenaccesskey', //填写你设定的key
 * 'appid'=>'wxdk1234567890', //填写高级调用功能的app id
 * 'appsecret'=>'xxxxxxxxxxxxxxxxxxx', //填写高级调用功能的密钥
 * );
 */
class WeiXinTool {

 private $appid;
 private $appsecret;
 private $access_token;
 private $mediaType = array('image' => array("jpg"), 'voice' => array('amr', 'MP3'), 'video' => array('mp4'), 'thumb' => array("jpg"));
 private $mediaMaxSize = array('image' => 131072, 'voice' => 262144, 'video' => 1048576, 'thumb' => 65536);
 private $tem_file_path = "";

// 授权地址
 const AUTH_URL = 'https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=%s&secret=%s';
// 素材上传
 const UPLOAD_MEDIA_URL = "http://file.api.weixin.qq.com/cgi-bin/media/upload?access_token=%s&type=%s";
 const GET_MEDIA_URL = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=%s&media_id=%s";
 const UPLOAD_NEWS_URL = "https://api.weixin.qq.com/cgi-bin/media/uploadnews?access_token=%s";

 public function __construct($options) {
  $this->appid = isset($options['appid']) ? $options['appid'] : '';
  $this->appsecret = isset($options['appsecret']) ? $options['appsecret'] : '';
  //需修改
  //上传图片临时文件目录自定义
  $this->tem_file_path = YYUC_FRAME_PATH . YYUC_PUB . '/' . Session::get('upath');
 }

 /**
  * 需修改
  * 具体业务需求，图文信息上传至素材库
  * 微站文章上传至微信素材
  * @param type $wid 
  * @param type $aid
  * @return int
  */
 public function uploadArticlesToWeiXinServer($wid, $aid) {

  //具体图文组装过程，需修改
  $m = new Model('website_article');
  $m_pubs = new Model('pubs');
  $m_pubs->find(array("id" => $wid));
  $m->find(array("wid" => $wid, 'id' => $aid));
  $res = array();
  if ($m->has_id() && $m_pubs->has_id()) {
   $res[] = $m->get_model_array();
//   var_dump($res);
   $m->votetouser = json_decode($m->votetouser, TRUE);
   $articles = $m->votetouser[0];
   $m_article = new Model('website_article');
   $ress = $m_article->where(array('wid' => $wid, 'id' => $articles))->list_all_array();
   $res = array_merge($res, $ress);
  } else {
   $errarr = array();
   $errarr['errcode'] = 44003;
   $errarr['errmsg'] = self::$errorno[$errarr['errcode']];
   return $errarr;
  }
  $items = array();
  foreach ($res as $k => $v) {
   $mediaid = $this->uploadMedia($v['picurl']);
   if ($mediaid['media_id']) {
    $thumb_media_id = $mediaid['media_id'];
   } else {
    return $mediaid;
   }
   $item = array(
    "thumb_media_id" => $thumb_media_id,
    "author" => $m_pubs->pubun,
    "title" => $v['title'],
    "content_source_url" => WeiXinTool::complateUrl(WeiSite::parseArticleLinkData($v)),
    "content" => $v['reply_content'], //内容 富文本
    "digest" => $v['description']//描述
   );
   $items[] = $item;
  }
  //以上具体图文组装过程，需修改

  $postData['articles'] = $items;
  $error = $this->uploadNews($postData);
  return $error;
 }

 /**
  * 需修改
  * 微站文章关键字匹配数据解析
  */
 public static function getArticleData($keyword) {
  global $wid;
  $m = new Model('website_article');
  $m->find(array('wid' => $wid, 'keyword@~' => " " . $keyword . " "));
  $res = array();
  if ($m->has_id()) {
   $res[] = array("tit" => $m->title, "pic" => $m->picurl, "dec" => $m->description, "url" => WeiSite::parseArticleLinkData($m->get_model_array()));
   $m->votetouser = json_decode($m->votetouser, TRUE);
   $articles = $m->votetouser[0];
   if (!empty($articles)) {
    foreach ($articles as $v) {
     $m_article = new Model('website_article');
     $m_article->find(array('wid' => $wid, 'id' => $v));
     $res[] = array("tit" => $m_article->title, "pic" => $m_article->picurl, "dec" => $m_article->description, "url" => WeiSite::parseArticleLinkData($m_article->get_model_array()));
    }
   }
   return $res;
  }
 }

 /**
  * 获取accesstoken
  * @param type $flag 强制刷新accesstoken 开关
  * @return type
  */
 public function getAccessToken($flag = FALSE) {
  $url = sprintf(self::AUTH_URL, $this->appid, $this->appsecret);
  $result = Cache::get(md5($url));
  if ($flag || empty($result)) {
   $result = $this->http_get($url);
   $result = json_decode($result, TRUE);
   if ($result['errcode']) {
    return $result['errcode'];
   }
   Cache::set(md5($url), $result, 1);
  }
  $this->access_token = $result['access_token'];
  return true;
 }

 /**
  * 上传媒体
  * @param type $file 媒体文件 $url或者物理路径地址
  * @param type $type 类型 
  * @return int
  * return 
  array (size=3)
  'type' => string 'image' (length=5)
  'media_id' => string '-0Lr3rX9mDYBB7i5bDydvwFHHm3zW2Uxt0OoDFBPmGRfYiwckiALqHH_DlP9jCm_' (length=64)
  'created_at' => int 1400477181
  */
 public function uploadMedia($file, $type = "image") {
  $file = self::complateUrl($file);
  $urlarr = parse_url($file);
  $filetype = explode(".", $urlarr['path']);
  $filetype = strtolower($filetype[count($filetype) - 1]);
  $resizeSize = 100; //图片处理后另存质量
  if (!key_exists($type, $this->mediaType) || !in_array($filetype, $this->mediaType[$type])) {
//   return 40005; //格式错误
   $errarr = array();
   $errarr['errcode'] = 40005;
   $errarr['errmsg'] = self::$errorno[$errarr['errcode']];
   return $errarr;
  }

  $temp_file = $this->tem_file_path . 'uploadMedia.' . $filetype;
  $temp_file_resize = $this->tem_file_path . 'uploadMediaResize.' . $filetype;
  file_put_contents($temp_file, self::http_get($file));
  $handle = fopen($temp_file, "r");
  $fstat = fstat($handle);

  if ($fstat['size'] > $this->mediaMaxSize[$type]) {
   $resizeSize = intval($this->mediaMaxSize[$type] / $fstat['size'] * 100);
   ImageTool::resizeImage($temp_file_resize, $temp_file, 400, 400, $resizeSize); //图片太大再处理压缩
   $temp_file = $temp_file_resize;
//   return 40006; //大小错误
  }
  $filePath = realpath($temp_file);
  $uploadUrl = sprintf(self::UPLOAD_MEDIA_URL, $this->access_token, $type);
  $postData = array("r" => time(), 'media' => "@{$filePath}");
  $result = self::http_post($uploadUrl, $postData);
  $result = json_decode($result, TRUE);
  return $result;
 }

 /**
  * 群发图文信息
  * @param type $touser 粉丝数组/粉丝组id
  * @param type $media_id
  * @return type
  */
 public function sendArticles($touser, $media_id) {
  $errarr = array();
  $postData = array();
  $postData['mpnews'] = array("media_id" => $media_id);
  $postData['msgtype'] = "mpnews";
  if (is_array($touser)) {
   //用户列表群发
   $postData['touser'] = $touser;
   $url = 'https://api.weixin.qq.com/cgi-bin/message/mass/send?access_token=%s';
  } else {
   $group = intval($touser);
   $groups = $this->getGroups(true);
   if (key_exists($group, $groups['list'])) {
    $postData['filter'] = array("group_id" => $group);
   } else {
    $errarr['errcode'] = 40050; //无效分组id
    $errarr['errmsg'] = self::$errorno[$errarr['errcode']];
    return $errarr;
   }
   $url = 'https://api.weixin.qq.com/cgi-bin/message/mass/sendall?access_token=%s';
  }
  $url = sprintf($url, $this->access_token);
  $result = self::http_post($url, self::json_encode($postData));
  $result = json_decode($result, TRUE);
  return $result;
 }

 /**
  * 删除群发信息
  * @param type $msgid
  * @return type
  */
 public function delSend($msgid) {
  $url = 'https://api.weixin.qq.com/cgi-bin/message/mass/delete?access_token=%s';
  $url = sprintf($url, $this->access_token);
  $postData = array('msgid' => $msgid, 'r' => time());
  $result = self::http_post($url, self::json_encode($postData));
  $result = json_decode($result, TRUE);
  return $result;
 }

 /**
  * 群发图文素材上传
  $postData = array('articles' => array($item, $item,...));
  $item = array(
  "thumb_media_id" => "WMQubqCECMQwAjqh8CI500LfhyoG0vmTTlKKJM5oP-of0uLML1_2s26j8XeIorDL",
  "author" => "xxx",
  "title" => "Happy Day",
  "content_source_url" => "www.qq.com",
  "content" => "content",
  "digest" => "digest"
  );
  * return 
  array (size=3)
  'type' => string 'news' (length=4)
  'media_id' => string 'OuXqv2dgZzxAmK4z-tvStgr6InG18oIllWkD6Tj1qJZVRg-2f64FDU2D3J7dptHs' (length=64)
  'created_at' => int 1400477183
  */
 public function uploadNews($postData) {
  $uploadUrl = sprintf(self::UPLOAD_NEWS_URL, $this->access_token);
  $result = self::http_post($uploadUrl, self::json_encode($postData));
  $result = json_decode($result, TRUE);
  return $result;
 }

 /**
  * 获取粉丝列表
  * @param type $nextOpenId
  * @return type
  */
 public function getAllConnects($nextOpenId = "") {
  $url = 'https://api.weixin.qq.com/cgi-bin/user/get?access_token=%s&next_openid=%s';
  $url = sprintf($url, $this->access_token, $nextOpenId);
  $result = self::http_get($url);
  $result = json_decode($result, TRUE);
  $count = count($result['data']['openid']);
  $list = $result['data']['openid'];
  if ($result['data']['openid'][$count - 1] == $result['next_openid']) {
   return $result['data']['openid'];
  } else {
   $templist = $this->getAllConnects($result['next_openid']);
   $list = array_merge($list, $templist);
   return $list;
  }
 }

 /**
  * 根据粉丝唯一id获取微信信息
  * @param type $openid
  * @return type
  */
 public function getFansInfo($openid) {
  $url = 'https://api.weixin.qq.com/cgi-bin/user/info?access_token=%s&openid=%s&lang=zh_CN';
  $url = sprintf($url, $this->access_token, $openid);
  $result = self::http_get($url);
  $result = json_decode($result, TRUE);
  return $result;
 }

 /**
  * 更新粉丝组信息
  * @param type $openid
  * @param type $groupid
  * @return type
  */
 public function updateFansGroups($openid, $groupid) {
  $url = 'https://api.weixin.qq.com/cgi-bin/groups/members/update?access_token=%s';
  $url = sprintf($url, $this->access_token);
  $postData = array("to_groupid" => $groupid, 'openid' => $openid);
  $result = self::http_post($url, self::json_encode($postData));
  $result = json_decode($result, TRUE);
  $this->getGroups(true);
  return $result;
 }

 /**
  * 获取粉丝组信息
  * @param type $openid
  * @return type
  */
 public function getFansGroupInfo($openid) {
  $url = 'https://api.weixin.qq.com/cgi-bin/groups/getid?access_token=%s';
  $url = sprintf($url, $this->access_token);
  $postData = array("r" => time(), 'openid' => $openid);
  $result = self::http_post($url, self::json_encode($postData));
  $result = json_decode($result, TRUE);
  return $result['groupid'];
 }

 /**
  * 获取唯一key
  * @param type $key
  * @return type
  */
 public function getKey($key) {
  return md5($this->appid . $this->appsecret . $key);
 }

 /**
  * 获取媒体图片到本地
  * @param type $mediaid
  * @return string
  */
 public function getMedia($mediaid) {
  $url = sprintf(self::GET_MEDIA_URL, $this->access_token, $mediaid);
  $result = self::http_get($url);
  $temp_file = $this->tem_file_path . 'getMedia.jpg';
  file_put_contents($temp_file, $result);
  return $temp_file;
 }

 /**
  * 用户组
  * @param type $flag 强制刷新用户组
  * @return type
  */
 public function getGroups($flag = false) {
  $key = $this->appid . 'gasdfev' . $this->appsecret;
  $result = Cache::get($key);
  if (empty($result) || $flag) {
   $url = 'https://api.weixin.qq.com/cgi-bin/groups/get?access_token=%s';
   $url = sprintf($url, $this->access_token);
   $result = self::http_get($url);
   $result = json_decode($result, TRUE);
   $temg = array();
   $temlist = array();
   foreach ($result['groups'] as $k => $v) {
    $temg[$v['id']] = $v;
    $temlist[$v['id']] = $v['name'];
   }
   $result['map'] = $temg;
   $result['list'] = $temlist;
   Cache::set($key, $result);
  }
  return $result;
 }

 /**
  * 新增用户组
  * @param type $name
  * @return type
  */
 public function createGroup($name) {
  $url = 'https://api.weixin.qq.com/cgi-bin/groups/create?access_token=%s';
  $url = sprintf($url, $this->access_token);
  $result = self::http_post($url, self::json_encode(array('group' => array('name' => $name))));
  $result = json_decode($result, TRUE);
  return $result;
 }

 /**
  * 修改用户组
  * @param type $id
  * @param type $name
  * @return type
  */
 public function modifyGroup($id, $name) {
  $url = 'https://api.weixin.qq.com/cgi-bin/groups/update?access_token=%s';
  $url = sprintf($url, $this->access_token);
  $result = self::http_post($url, self::json_encode(array('group' => array('id' => $id, 'name' => $name))));
  $result = json_decode($result, TRUE);
  return $result;
 }

 /**
  * 多客服接入
  * @global type $wid
  * @param type $postObj
  */
 public static function responseService($postObj) {
  global $wid;
  $fromUsername = $postObj->FromUserName;
  $toUsername = $postObj->ToUserName;
  $textTpl = "<xml>
<ToUserName><![CDATA[%s]]></ToUserName>
<FromUserName><![CDATA[%s]]></FromUserName>
<CreateTime>%s</CreateTime>
<MsgType><![CDATA[transfer_customer_service]]></MsgType>
</xml>";
  $resstr = sprintf($textTpl, $fromUsername, $toUsername, time());
  echo $resstr;
 }

 /**
  * 微信回复多图文
  * @global type $wid
  * @param type $res
  * array(array(),array()
  * );
  * @param type $rid
  * @param type $postObj
  */
 public static function response_morearts($res, $postObj) {
  global $wid;
  $fromUsername = $postObj->FromUserName;
  $toUsername = $postObj->ToUserName;
  $textTpl = "<xml>
 <ToUserName><![CDATA[%s]]></ToUserName>
 <FromUserName><![CDATA[%s]]></FromUserName>
 <CreateTime>%s</CreateTime>
 <MsgType><![CDATA[%s]]></MsgType>
 <ArticleCount>%s</ArticleCount>
 <Articles>
 ITEM
 </Articles>
 </xml>";
  $resstr = sprintf($textTpl, $fromUsername, $toUsername, time(), "news", count($res));
  $item = '';
  $subitem = "<item>
 <Title><![CDATA[%s]]></Title>
 <Description><![CDATA[%s]]></Description>
 <PicUrl><![CDATA[%s]]></PicUrl>
 <Url><![CDATA[%s]]></Url>
 </item>";
  foreach ($res as $r) {
   $r['url'] = self::parseUrl($r['url']);
   $item .= sprintf($subitem, $r['tit'], $r['des'], self::complateUrl($r['pic']), self::replaceToWXUrl(self::complateUrl($r['url']), $postObj));
  }
  $resstr = str_replace('ITEM', $item, $resstr);
  echo $resstr;
 }

 /**
  * url解析
  * @param type $url
  * @return string
  */
 public static function complateUrl($url) {
  if (false === stristr($url, "http://")) {//查找http:// 如果不存在
   if (0 === strpos($url, '/')) {//查找首字母 如果存在
    $url = substr($url, 1); //去除/
   }
   $url = "http://" . $_SERVER['HTTP_HOST'] . '/' . $url; //拼接完整路径
  }
  return $url;
 }

 /**
  * 微信url固定参数替换
  * @param type $url
  * @param type $postObj
  * @return type
  */
 public static function replaceToWXUrl($url, $postObj) {
  global $wechatid;
  return str_ireplace('fromUsername', $wechatid, $url);
 }

 /**
  * 完成以下行为
  * parseUrlParam
  * setUrlPublicParam
  * buildUrlParam
  * @param type $url
  * @param type $other 附加参数 基础参数wid wxid wechatid
  */
 public static function parseUrl($url, $other = array()) {
  $url = self::parseUrlParam($url);
  $url = self::setUrlPublicParam($url);
  if (is_array($other) && !empty($other)) {
   $url['param'] = array_merge($url['param'], $other);
  }
  $url = self::buildUrlParam($url);
  return $url;
 }

 /**
  * 分析url
  * @param type $url
  * @return type
  */
 public static function parseUrlParam($url) {
  $temp = explode("?", $url);
  $url0 = $temp[0];
  $url1 = $temp[1];
  $p = explode("&", $url1);
  $param = array();
  foreach ($p as $v) {
   $tempp = explode("=", $v);
   $param[$tempp[0]] = $tempp[1];
  }
  return array("url" => $url0, "param" => $param);
 }

 /**
  * 组装url
  * @param type $arr
  * @return type
  */
 public static function buildUrlParam($arr) {
  $url = $arr['url'];
  $param = $arr['param'];
  $param_arr = array();
  foreach ($param as $k => $v) {
   if ($k == "") continue;
   $param_arr[] = $k . "=" . $v;
  }
  return $url . "?" . implode("&", $param_arr) . "#mp.weixin.qq.com";
 }

 /**
  * 设置微信保留参数信息
  * @global type $uid
  * @global type $wid
  * @global type $wechatid
  * @param type $url
  * @return type
  */
 public static function setUrlPublicParam($url) {
  global $uid, $wid, $wechatid;
  $url['param']['wid'] = $wid;
  $url['param']['wxid'] = $wechatid;
  $url['param']['wechatid'] = $wechatid;
  return $url;
 }

 public static $errorno = array(
  '-1' => '系统繁忙',
  '0' => '请求成功',
  '40001' => '获取access_token时AppSecret错误，或者access_token无效',
  '40002' => '不合法的凭证类型',
  '40003' => '不合法的OpenID',
  '40004' => '不合法的媒体文件类型',
  '40005' => '不合法的文件类型',
  '40006' => '不合法的文件大小',
  '40007' => '不合法的媒体文件id',
  '40008' => '不合法的消息类型',
  '40009' => '不合法的图片文件大小',
  '40010' => '不合法的语音文件大小',
  '40011' => '不合法的视频文件大小',
  '40012' => '不合法的缩略图文件大小',
  '40013' => '不合法的APPID',
  '40014' => '不合法的access_token',
  '40015' => '不合法的菜单类型',
  '40016' => '不合法的按钮个数',
  '40017' => '不合法的按钮个数',
  '40018' => '不合法的按钮名字长度',
  '40019' => '不合法的按钮KEY长度',
  '40020' => '不合法的按钮URL长度',
  '40021' => '不合法的菜单版本号',
  '40022' => '不合法的子菜单级数',
  '40023' => '不合法的子菜单按钮个数',
  '40024' => '不合法的子菜单按钮类型',
  '40025' => '不合法的子菜单按钮名字长度',
  '40026' => '不合法的子菜单按钮KEY长度',
  '40027' => '不合法的子菜单按钮URL长度',
  '40028' => '不合法的自定义菜单使用用户',
  '40029' => '不合法的oauth_code',
  '40030' => '不合法的refresh_token',
  '40031' => '不合法的openid列表',
  '40032' => '不合法的openid列表长度',
  '40033' => '不合法的请求字符，不能包含\uxxxx格式的字符',
  '40035' => '不合法的参数',
  '40038' => '不合法的请求格式',
  '40039' => '不合法的URL长度',
  '40050' => '不合法的分组id',
  '40051' => '分组名字不合法',
  '40059' => '不合法的消息id',
  '41001' => '缺少access_token参数',
  '41002' => '缺少appid参数',
  '41003' => '缺少refresh_token参数',
  '41004' => '缺少secret参数',
  '41005' => '缺少多媒体文件数据',
  '41006' => '缺少media_id参数',
  '41007' => '缺少子菜单数据',
  '41008' => '缺少oauth code',
  '41009' => '缺少openid',
  '42001' => 'access_token超时',
  '42002' => 'refresh_token超时',
  '42003' => 'oauth_code超时',
  '43001' => '需要GET请求',
  '43002' => '需要POST请求',
  '43003' => '需要HTTPS请求',
  '43004' => '需要接收者关注',
  '43005' => '需要好友关系',
  '44001' => '多媒体文件为空',
  '44002' => 'POST的数据包为空',
  '44003' => '图文消息内容为空',
  '44004' => '文本消息内容为空',
  '45001' => '多媒体文件大小超过限制',
  '45002' => '消息内容超过限制',
  '45003' => '标题字段超过限制',
  '45004' => '描述字段超过限制',
  '45005' => '链接字段超过限制',
  '45006' => '图片链接字段超过限制',
  '45007' => '语音播放时间超过限制',
  '45008' => '图文消息超过限制',
  '45009' => '接口调用超过限制',
  '45010' => '创建菜单个数超过限制',
  '45015' => '回复时间超过限制',
  '45016' => '系统分组，不允许修改',
  '45017' => '分组名字过长',
  '45018' => '分组数量超过上限',
  '46001' => '不存在媒体数据',
  '46002' => '不存在的菜单版本',
  '46003' => '不存在的菜单数据',
  '46004' => '不存在的用户',
  '47001' => '解析JSON/XML内容错误',
  '48001' => 'api功能未授权',
  '50001' => '用户未授权该api'
 );

 /**
  * GET 请求
  * @param string $url
  */
 public static function http_get($url) {
  if (!function_exists('curl_init')) {
   die('curl 未开启');
  };
  $oCurl = curl_init();
  if (stripos($url, "https://") !== FALSE) {
   curl_setopt($oCurl, CURLOPT_SSL_VERIFYPEER, FALSE);
   curl_setopt($oCurl, CURLOPT_SSL_VERIFYHOST, FALSE);
  }
  curl_setopt($oCurl, CURLOPT_URL, $url);
  curl_setopt($oCurl, CURLOPT_RETURNTRANSFER, 1);
  $sContent = curl_exec($oCurl);
  $aStatus = curl_getinfo($oCurl);
  curl_close($oCurl);
  if (intval($aStatus["http_code"]) == 200) {
   return $sContent;
  } else {
   return false;
  }
 }

 /**
  * POST 请求
  * @param string $url
  * @param array $param
  * @return string content
  */
 public static function http_post($url, $param, $httpBuildQuery = false) {
  if (!function_exists('curl_init')) {
   die('curl 未开启');
  };
  $oCurl = curl_init();
  if (stripos($url, "https://") !== FALSE) {
   curl_setopt($oCurl, CURLOPT_SSL_VERIFYPEER, FALSE);
   curl_setopt($oCurl, CURLOPT_SSL_VERIFYHOST, false);
  }
  curl_setopt($oCurl, CURLOPT_URL, $url);
  curl_setopt($oCurl, CURLOPT_RETURNTRANSFER, 1);
//  curl_setopt($oCurl, CURLOPT_HTTPHEADER, $header);//设置HTTP头
  curl_setopt($oCurl, CURLOPT_POST, 1);
  if ($httpBuildQuery) {
   $param = http_build_query($param);
  }
  curl_setopt($oCurl, CURLOPT_POSTFIELDS, $param);
  $sContent = curl_exec($oCurl);
  $aStatus = curl_getinfo($oCurl);
  curl_close($oCurl);
  if (intval($aStatus["http_code"]) == 200) {
   return $sContent;
  } else {
   return false;
  }
 }

 /**
  * 微信api不支持中文转义的json结构
  * @param array $arr
  */
 static function json_encode($arr) {
  $parts = array();
  $is_list = false;
  //Find out if the given array is a numerical array
  $keys = array_keys($arr);
  $max_length = count($arr) - 1;
  if (($keys [0] === 0) && ($keys [$max_length] === $max_length )) { //See if the first key is 0 and last key is length - 1
   $is_list = true;
   for ($i = 0; $i < count($keys); $i ++) { //See if each key correspondes to its position
    if ($i != $keys [$i]) { //A key fails at position check.
     $is_list = false; //It is an associative array.
     break;
    }
   }
  }
  foreach ($arr as $key => $value) {
   if (is_array($value)) { //Custom handling for arrays
    if ($is_list) $parts [] = self::json_encode($value); /* :RECURSION: */
    else $parts [] = '"' . $key . '":' . self::json_encode($value); /* :RECURSION: */
   } else {
    $str = '';
    if (!$is_list) $str = '"' . $key . '":';
    //Custom handling for multiple data types
    if (is_numeric($value) && $value < 2000000000) $str .= $value; //Numbers
    elseif ($value === false) $str .= 'false'; //The booleans
    elseif ($value === true) $str .= 'true';
    else $str .= '"' . addslashes($value) . '"';
//All other things
// :TODO: Is there any more datatype we should be in the lookout for? (Object?)
    $parts [] = $str;
   }
  }
  $json = implode(',', $parts);
  if ($is_list) return '[' . $json . ']'; //Return numerical JSON
  return '{' . $json . '}'; //Return associative JSON
 }

}