start a restructure

Structural/Facade/BiosInterface.php

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+<?php
+
+namespace DesignPatterns\Facade;
+
+/**
+ * Class BiosInterface
+ */
+interface BiosInterface
+{
+    /**
+     * execute the BIOS
+     */
+    public function execute();
+
+    /**
+     * wait for halt
+     */
+    public function waitForKeyPress();
+
+    /**
+     * launches the OS
+     *
+     * @param OsInterface $os
+     */
+    public function launch(OsInterface $os);
+
+    /**
+     * power down BIOS
+     */
+    public function powerDown();
+}

Structural/Facade/Facade.php

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+<?php
+
+namespace DesignPatterns\Facade;
+
+/**
+ *
+ * 
+ */
+class Facade
+{
+    /**
+     * @var OsInterface
+     */
+    protected $os;
+
+    /**
+     * @var BiosInterface
+     */
+    protected $bios;
+
+    /**
+     * This is the perfect time to use a dependency injection container
+     * to create an instance of this class
+     *
+     * @param BiosInterface $bios
+     * @param OsInterface   $os
+     */
+    public function __construct(BiosInterface $bios, OsInterface $os)
+    {
+        $this->bios = $bios;
+        $this->os = $os;
+    }
+
+    /**
+     * turn on the system
+     */
+    public function turnOn()
+    {
+        $this->bios->execute();
+        $this->bios->waitForKeyPress();
+        $this->bios->launch($this->os);
+    }
+
+    /**
+     * turn off the system
+     */
+    public function turnOff()
+    {
+        $this->os->halt();
+        $this->bios->powerDown();
+    }
+}

Structural/Facade/OsInterface.php

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+<?php
+
+namespace DesignPatterns\Facade;
+
+/**
+ * Class OsInterface
+ */
+interface OsInterface
+{
+    /**
+     * halt the OS
+     */
+    public function halt();
+}

Structural/Facade/README.md

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+# Facade
+
+## Purpose
+
+The primary goal of a Facade Pattern is not to avoid you to read the manual of a complex API. It's only a side-effect.
+The first goal is to reduce coupling and follow the Law of Demeter.
+
+A Facade is meant to decouple a client and a sub-system by embedding many (but sometimes just one) interface, and of course to reduce complexity.
+
+* A facade does not forbid you the access to the sub-system
+* You can (you should) have multiple facades for one sub-system
+
+That's why a good facade has no `new` in it. If there are multiple creations for each method, it is not a Facade, it's a Builder or a
+[Abstract|Static|Simple] Factory [Method].
+
+The best facade has no `new` and a constructor with interface-type-hinted parameters.
+If you need creation of new instances, use a Factory as argument.

Structural/Facade/Test/FacadeTest.php

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+<?php
+
+namespace DesignPatterns\Tests\Facade;
+
+use DesignPatterns\Facade\Facade as Computer;
+
+/**
+ * FacadeTest shows example of facades
+ */
+class FacadeTest extends \PHPUnit_Framework_TestCase
+{
+
+    public function getComputer()
+    {
+        $bios = $this->getMockBuilder('DesignPatterns\Facade\BiosInterface')
+                ->setMethods(array('launch', 'execute', 'waitForKeyPress'))
+                ->disableAutoload()
+                ->getMock();
+        $operatingSys = $this->getMockBuilder('DesignPatterns\Facade\OsInterface')
+                ->setMethods(array('getName'))
+                ->disableAutoload()
+                ->getMock();
+        $bios->expects($this->once())
+                ->method('launch')
+                ->with($operatingSys);
+        $operatingSys
+                ->expects($this->once())
+                ->method('getName')
+                ->will($this->returnValue('Linux'));
+
+        $facade = new Computer($bios, $operatingSys);
+        return array(array($facade, $operatingSys));
+    }
+
+    /**
+     * @dataProvider getComputer
+     */
+    public function testComputerOn(Computer $facade, $os)
+    {
+        // interface is simpler :
+        $facade->turnOn();
+        // but I can access to lower component
+        $this->assertEquals('Linux', $os->getName());
+    }
+}