Add command help option

Mage/Command/AbstractCommand.php

@@ -26,6 +26,10 @@ abstract class AbstractCommand
      */
     protected $config = null;
 
+    private $helpMessage;
+    private $usageExamples = [];
+    private $syntaxMessage;
+
     /**
      * Runs the Command
      * @return integer exit code
@@ -52,4 +56,65 @@ abstract class AbstractCommand
     {
         return $this->config;
     }
+
+    public function setHelpMessage($message)
+    {
+        $this->helpMessage = $message;
+
+        return $this;
+    }
+
+    public function addUsageExample($snippet, $description = '')
+    {
+        array_push($this->usageExamples, [$snippet, $description]);
+
+        return $this;
+    }
+
+    public function setSyntaxMessage($message)
+    {
+        $this->syntaxMessage = $message;
+
+        return $this;
+    }
+
+    public function getInfoMessage()
+    {
+        $indent = str_repeat(" ", 4);
+
+        $output = "";
+
+        if (!empty($this->helpMessage)) {
+            $output .= "\n";
+            $output .= $this->helpMessage . "\n";
+        }
+
+        if (!empty($this->syntaxMessage)) {
+            $output .= "\n";
+            $output .= "Syntax:\n";
+            $output .= $indent;
+            $output .= $this->syntaxMessage;
+            $output .= "\n";
+        }
+
+        if (!empty($this->usageExamples)) {
+            $output .= "\n";
+            $output .= "Usage examples:\n";
+            foreach ($this->usageExamples as $example) {
+                $snippet = $example[0];
+                $description = $example[1];
+                $output .= "$indent* ";
+                if (!empty($description)) {
+                    $description = rtrim($description, ': ') . ":";
+                    $output .= $description;
+                    $output .= "\n$indent$indent";
+                }
+
+                $output .= $snippet;
+                $output .= "\n";
+            }
+        }
+
+        return $output;
+    }
 }