Refactor writers for better DI (#427)

This commit is a big refactor that improves the code organization.
It focuses on how dependencies are injected into the different classes. This is now done via some factories.

Also, the code is now built around entities (data model that only exposes getters and setters), managers (used to manage an entity) and helpers (used by the managers to perform some specific tasks).

The refactoring is not fully complete, as some dependencies are still hidden...

src/Spout/Writer/ODS/Helper/FileSystemHelper.php

@@ -2,8 +2,10 @@
 
 namespace Box\Spout\Writer\ODS\Helper;
 
+use Box\Spout\Writer\Common\Helper\FileSystemWithRootFolderHelperInterface;
 use Box\Spout\Writer\Common\Helper\ZipHelper;
-use Box\Spout\Writer\ODS\Internal\Worksheet;
+use Box\Spout\Writer\Entity\Worksheet;
+use Box\Spout\Writer\ODS\Manager\WorksheetManager;
 
 /**
  * Class FileSystemHelper
@@ -12,7 +14,7 @@ use Box\Spout\Writer\ODS\Internal\Worksheet;
  *
  * @package Box\Spout\Writer\ODS\Helper
  */
-class FileSystemHelper extends \Box\Spout\Common\Helper\FileSystemHelper
+class FileSystemHelper extends \Box\Spout\Common\Helper\FileSystemHelper implements FileSystemWithRootFolderHelperInterface
 {
     const APP_NAME = 'Spout';
     const MIMETYPE = 'application/vnd.oasis.opendocument.spreadsheet';
@@ -172,11 +174,12 @@ EOD;
     /**
      * Creates the "content.xml" file under the root folder
      *
+     * @param WorksheetManager $worksheetManager
      * @param Worksheet[] $worksheets
      * @param StyleHelper $styleHelper
      * @return FileSystemHelper
      */
-    public function createContentFile($worksheets, $styleHelper)
+    public function createContentFile($worksheetManager, $worksheets, $styleHelper)
     {
         $contentXmlFileContents = <<<EOD
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
@@ -196,9 +199,9 @@ EOD;
 
         foreach ($worksheets as $worksheet) {
             // write the "<table:table>" node, with the final sheet's name
-            fwrite($contentXmlHandle, $worksheet->getTableElementStartAsString());
+            fwrite($contentXmlHandle, $worksheetManager->getTableElementStartAsString($worksheet));
 
-            $worksheetFilePath = $worksheet->getWorksheetFilePath();
+            $worksheetFilePath = $worksheet->getFilePath();
             $this->copyFileContentsToTarget($worksheetFilePath, $contentXmlHandle);
 
             fwrite($contentXmlHandle, '</table:table>');