Some updates

src/SmsGateway/Auth/DatabaseAuth.php

@@ -0,0 +1,8 @@
+<?php
+namespace SmsGateway\Backend;
+
+use SmsGateway\AuthInterface;
+
+class DatabaseAuth implements AuthInterface
+{
+}

src/SmsGateway/AuthInterface

@@ -1,6 +1,6 @@
 <?php
 namespace SmsGateway;
 
-interface BackendInterface
+interface AuthInterface
 {
-}
+}

src/SmsGateway/Backend/DatabaseBackend.php

@@ -1,8 +0,0 @@
-<?php
-namespace SmsGateway\Backend;
-
-use SmsGateway\BackendInterface;
-
-class DatabaseBackend implements BackendInterface
-{
-}

src/SmsGateway/Sender/GnokiiSender.php

@@ -5,4 +5,18 @@ use SmsGateway\SenderInterface;
 
 class GnokiiSender implements SenderInterface
 {
-}
+    private $gnokiiPath;
+
+    public function __construct($gnokiiPath)
+    {
+        $this->gnokiiPath = $gnokiiPath;
+
+        if (!is_executable($this->gnokiiPath)) {
+            throw new \Exception('Specified Gnokii executable is not executable by me!');
+    }
+
+    public function send($recipient, $message)
+    {
+        return true;
+    }
+}

src/SmsGateway/SenderInterface.php

@@ -3,4 +3,12 @@ namespace SmsGateway;
 
 interface SenderInterface
 {
-}
+    /**
+     *
+     * @param  string $recipient
+     * @param  string $message
+     * @return boolean           true upon success. On error, throws exceptions.
+     * @throws Exception         Upon sending error. Gnokii output will be
+     *                           stored in $e->message
+    public function send($recipient, $message);
+}