<?php
class DMS implements DMSInterface {

	static $dmsFolder = 'dms-assets';   //folder to store the documents in

	//How many documents to store in a single folder. The square of this number is the maximum number of documents.
	//The number should be a multiple of 10
	static $dmsFolderSize = 1000;
	static $modelClass = 'DMSDocument';
	
	static function set_model_class($className){
		self::$modelClass = $className;
	}


	/**
	 * Factory method that returns an instance of the DMS. This could be any class that implements the DMSInterface.
	 * @static
	 * @return DMSInterface An instance of the Document Management System
	 */
	static function getDMSInstance() {
		$dmsPath = self::get_DMS_path();

		$dms = new DMS();
		if (!is_dir($dmsPath)) {
			self::createStorageFolder($dmsPath);
		}

		if (!file_exists($dmsPath . DIRECTORY_SEPARATOR . '.htaccess')) {
			//restrict access to the storage folder
			copy(BASE_PATH . DIRECTORY_SEPARATOR . 'dms' . DIRECTORY_SEPARATOR . 'resources' . DIRECTORY_SEPARATOR . '.htaccess',  $dmsPath . DIRECTORY_SEPARATOR . '.htaccess');
			copy(BASE_PATH . DIRECTORY_SEPARATOR . 'dms' . DIRECTORY_SEPARATOR . 'resources' . DIRECTORY_SEPARATOR . 'web.config', $dmsPath . DIRECTORY_SEPARATOR . 'web.config');
		}
		return $dms;
	}

	static function get_DMS_path() {
		return BASE_PATH . DIRECTORY_SEPARATOR . self::$dmsFolder;
	}

	static function transformFileToFilePath($file) {
		//confirm we have a file
		$filePath = null;
		if (is_string($file)) $filePath = $file;
		elseif (is_object($file) && $file->is_a("File")) $filePath = $file->Filename;

		if (!$filePath) throw new FileNotFoundException();

		return $filePath;
	}

	/**
	 * Takes a File object or a String (path to a file) and copies it into the DMS. The original file remains unchanged.
	 * When storing a document, sets the fields on the File has "tag" metadata.
	 * @param $file File object, or String that is path to a file to store, e.g. "assets/documents/industry/supplied-v1-0.pdf"

	 */
	function storeDocument($file) {
		$filePath = self::transformFileToFilePath($file);
		
		//create a new document and get its ID
		$modelClass = self::$modelClass;
		$doc = new $modelClass();
		$doc->write();
		$doc->storeDocument($filePath);

		return $doc;
	}

	/**
	 *
	 * Returns a number of Document objects based on the a search by tags. You can search by category alone,
	 * by tag value alone, or by both. I.e: getByTag("fruits",null); getByTag(null,"banana"); getByTag("fruits","banana")
	 * @param null $category The metadata category to search for
	 * @param null $value The metadata value to search for
	 * @param bool $showEmbargoed Boolean that specifies if embargoed documents should be included in results
	 * @return DocumentInterface
	 */
	function getByTag($category = null, $value = null, $showEmbargoed = false) {
		// TODO: Implement getByTag() method.
	}

	/**
	 * Returns a number of Document objects that match a full-text search of the Documents and their contents
	 * (if contents is searchable and compatible search module is installed - e.g. FullTextSearch module)
	 * @param $searchText String to search for
	 * @param bool $showEmbargoed Boolean that specifies if embargoed documents should be included in results
	 * @return DocumentInterface
	 */
	function getByFullTextSearch($searchText, $showEmbargoed = false) {
		// TODO: Implement getByFullTextSearch() method.
	}

	/**
	 * Returns a list of Document objects associated with a Page
	 * @param $page SiteTree to fetch the associated Documents from
	 * @param bool $showEmbargoed Boolean that specifies if embargoed documents should be included in results
	 * @return DataList Document list associated with the Page
	 */
	function getByPage($page, $showEmbargoed = false) {
		// TODO: Implement getByPage() method.
	}

	/**
	 * Creates a storage folder for the given path
	 * @param $path Path to create a folder for
	 */
	static function createStorageFolder($path) {
		if (!is_dir($path)) {
			mkdir($path, 0777);
		}
	}

	/**
	 * Calculates the storage path from a database DMSDocument ID
	 */
	static function getStorageFolder($id) {
		$folderName = intval($id / self::$dmsFolderSize);
		return $folderName;
	}
}