add specific functions for each level

Logger.php

@@ -86,14 +86,52 @@ class Logger
     public function log($string)
     {
         $log_source = sprintf("%s:%d", basename(debug_backtrace()[0]['file']), debug_backtrace()[0]['line']);
+        $log_string = call_user_func_array("Logger::get_message", func_get_args());
+        $this->do_write($log_string, $log_source, "info");
+    }
+
+    /* Log Debug */
+    public function debug($string)
+    {
+        $log_source = sprintf("%s:%d", basename(debug_backtrace()[0]['file']), debug_backtrace()[0]['line']);
+        $log_string = call_user_func_array("Logger::get_message", func_get_args());
+        $this->do_write($log_string, $log_source, "debug");
+    }
+
+    /* Log Info */
+    public function info($string)
+    {
+        $log_source = sprintf("%s:%d", basename(debug_backtrace()[0]['file']), debug_backtrace()[0]['line']);
+        $log_string = call_user_func_array("Logger::get_message", func_get_args());
+        $this->do_write($log_string, $log_source, "info");
+    }
+
+    /* Log Warning */
+    public function warning($string)
+    {
+        $log_source = sprintf("%s:%d", basename(debug_backtrace()[0]['file']), debug_backtrace()[0]['line']);
+        $log_string = call_user_func_array("Logger::get_message", func_get_args());
+        $this->do_write($log_string, $log_source, "warn");
+    }
+
+    /* Log Error */
+    public function error($string)
+    {
+        $log_source = sprintf("%s:%d", basename(debug_backtrace()[0]['file']), debug_backtrace()[0]['line']);
+        $log_string = call_user_func_array("Logger::get_message", func_get_args());
+        $this->do_write($log_string, $log_source, "error");
+    }
+
+    /* Format Message */
+    private function get_message($string) {
         $args = func_get_args();
         if (count($args) > 1) {
             array_shift($args);
-            $log_string = vsprintf($string, $args);
+            $message = vsprintf($string, $args);
         } else {
-            $log_string = $string;
+            $message = $string;
         }
-        $this->do_write($log_string, $log_source, "info");
+        return $message;
     }
 
     /*