my php code is secure? php to pdo over eval function - php

Question

i'm writing a php web script with mvc, but i'm concerned about code is safe.
i fear most "eval($str)", but i try a lot of php function string but nothing happened.
$a = func_get_args();
if((func_num_args()-1)%2 == 0){
$str = "";
array_shift($a);
for($i = 0;$i<sizeof($a);$i++){
if($i%2==0){
if(!is_numeric($a[$i])){
if($a[$i] == 'filter'){
$filter=1;
}
$str.= "$".stripslashes($a[$i])." = ";
}else{
$str.= 'page';
}
}else{
if($filter != 1){
if(is_numeric($a[$i])){
$str.= stripslashes($a[$i]).";";
}else{
$str.=1;
}
}else{
$arr = explode("-",$a[$i]);
$dizz = 'array(';
for($j=0;$j<sizeof($arr);$j++){
if(($j%2)==0){
$dizz .= '\''.stripslashes($arr[$j]).'\'=>';
}else{
$dizz .= '\''.stripslashes($arr[$j]).'\',';
}
}
$dizz = rtrim($dizz,',');
$dizz .= ');';
$str.= $dizz;
}
}
}
eval($str);
}
$filter = isset($filter) ? $filter : false;
$page= isset($page) ? $page: '';
$count= isset($count) ? $count: '';
if($count == ''){
switch ($process) {
case 'table':
$count = 40;
break;
case 'detailed':
$count = 3;
break;
case 'mobile':
$count = 12;
break;
default:
$count = '';
break;
}
}
if($count != ''){
if(is_numeric($count )){
if($count <=200 && $count >0){
$count = $count ;
}else{
$count = 40;
}
}else{
$count = 1;
}
}
if(!is_numeric($page)){
$page= 1;
}
to sql query->
$new_filter = "Where ";
if($filter){
foreach ($filteras $key => $value) {
$new_filter .= 'k.'.$key.'='.$value.' and ';
}
$new_filter = rtrim($new_filter,' and ');
$filter= $new_filter;
}else{
$filter= '';
}
$limit = ($limit) ? 'LIMIT 30' : '';
if($id == ''){
$where = $filter;
}else{
$where = $id;
}
$query = 'select * from kullanici as k join kisiler as ki on k.id = ki.kullanici_id join iletisim as i on k.id = i.kullanici_id '.$where.' '.$siralama.' '.$limit;
$query = $this->_db->prepare($query);
$query->execute();
example url:
profile/show/mobile/page/4/count/5/filter/echo-"'xzcxza'"-sadas-asdxc
this results:
$page = 4;$count= 5;$filter= array('echo'=>'%22%27xzcxza%27%22','sadas'=>'asdxc');