I want to insert newpost on Front-end of wordpress. And i want to rename images name during upload for my code below like: "MemberUpload---dd/mm/yy--random_number-[width]x[height].jpg" (For all size: thumbnail, medium, large, full and custom size) My code upload i'm using for my theme.. Thanks friends verymuch! ;)

// Upload 
if (!function_exists('wp_generate_attachment_metadata')){
                    require_once(ABSPATH . "wp-admin" . '/includes/image.php');
                    require_once(ABSPATH . "wp-admin" . '/includes/file.php');
                    require_once(ABSPATH . "wp-admin" . '/includes/media.php');
                }
                 if ($_FILES) {
                    foreach ($_FILES as $file => $array) {
                        if ($_FILES[$file]['error'] !== UPLOAD_ERR_OK) {
                            return "Upload Err: " . $_FILES[$file]['error'];
                        }
                        $attach_id = media_handle_upload( $file, $newPost );
                    }   
                }
                if ($attach_id > 0){
                    //and if you want to set that image as Post  then use:
                    update_post_meta($newPost,'Uploaded_img_id',$attach_id);
                }
// END upload

I want to insert newpost on Front-end of wordpress. 
And i want to rename images name during upload for my code below
Result like: "MemberUpload__dd/mm/yy__random_number_[width]x[height].jpg"  
(For all size: thumbnail, medium, large, full and custom size) My code upload i'm using for my theme..  
Thanks friends verymuch! ;)

// Upload 
if (!function_exists('wp_generate_attachment_metadata')){
                    require_once(ABSPATH . "wp-admin" . '/includes/image.php');
                    require_once(ABSPATH . "wp-admin" . '/includes/file.php');
                    require_once(ABSPATH . "wp-admin" . '/includes/media.php');
                }
                 if ($_FILES) {
                    foreach ($_FILES as $file => $array) {
                        if ($_FILES[$file]['error'] !== UPLOAD_ERR_OK) {
                            return "Upload Err: " . $_FILES[$file]['error'];
                        }
                        $attach_id = media_handle_upload( $file, $newPost );
                    }   
                }
                if ($attach_id > 0){
                    //and if you want to set that image as Post  then use:
                    update_post_meta($newPost,'Uploaded_img_id',$attach_id);
                }
// END upload