<?php
// Own namespace
namespace CoreFramework\Template\Engine;

// Import framework stuff
use CoreFramework\Factory\ObjectFactory;
use CoreFramework\Filesystem\InvalidDirectoryException;
use CoreFramework\Parser\Xml\XmlParser;
use CoreFramework\Registry\Registry;
use CoreFramework\Template\CompileableTemplate;
use CoreFramework\Template\Engine\BaseTemplateEngine;

// Import SPL stuff
use \SplFileInfo;
use \UnexpectedValueException;

/**
 * A Menu template engine class
 *
 * @author		Roland Haeder <webmaster@shipsimu.org>
 * @version		0.0.0
 * @copyright	Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
 * @license		GNU GPL 3.0 or any newer version
 * @link		http://www.shipsimu.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
class MenuTemplateEngine extends BaseTemplateEngine implements CompileableTemplate {
	/**
	 * Main nodes in the XML tree ('menu' is ignored)
	 */
	private $mainNodes = array(
		'block-list',
	);

	/**
	 * Sub nodes in the XML tree
	 */
	private $subNodes = array(
		'entry-list',
		'entry',
		'entry-id',
		'entries-content',
		'block-header',
		'block-footer',
		'footer-id',
		'footer-class',
		'footer-text',
		'block',
		'title',
		'title-id',
		'title-class',
		'title-text',
		'design',
		'text',
		'advert',
		'anchor',
		'anchor-id',
		'anchor-text',
		'anchor-title',
		'anchor-href',
	);

	/**
	 * Variables for a menu entry
	 */
	private $menuEntryVariables = array(
		// List entry
		'entry_id',
		// Anchor
		'anchor-id',
		'anchor-text',
		'anchor-title',
		'anchor-href',
	);

	/**
	 * Variables for a menu block
	 */
	private $menuBlockVariables = array(
		// Title
		'title_id',
		'title_class',
		'title_text',
		// Content is taken from menuEntries
		// Footer
		'footer_id',
		'footer_class',
		'footer_text',
	);

	/**
	 * Rendered menu entries
	 */
	private $menuEntries = array();

	/**
	 * Rendered menu blocks
	 */
	private $menuBlocks = array();

	/**
	 * Menu instance
	 */
	private $menuInstance = NULL;

	/**
	 * Current main node
	 */
	private $curr = array();

	/**
	 * Content from dependency
	 */
	private $dependencyContent = array();

	/**
	 * Protected constructor
	 *
	 * @return	void
	 */
	protected function __construct () {
		// Call parent constructor
		parent::__construct(__CLASS__);
	}

	/**
	 * Creates an instance of the class TemplateEngine and prepares it for usage
	 *
	 * @param	$menuInstance			A RenderableMenu instance
	 * @return	$templateInstance		An instance of TemplateEngine
	 * @throws	UnexpectedValueException		If the found $templateBasePath is empty or not a string
	 * @throws	InvalidDirectoryException	If $templateBasePath is no directory or not found
	 * @throws	BasePathReadProtectedException	If $templateBasePath is
	 *											read-protected
	 */
	public static final function createMenuTemplateEngine (RenderableMenu $menuInstance) {
		// Get a new instance
		$templateInstance = new MenuTemplateEngine();

		// Get the application instance from registry
		$applicationInstance = Registry::getRegistry()->getInstance('app');

		// Determine base path
		$templateBasePath = $templateInstance->getConfigInstance()->getConfigEntry('application_base_path') . $applicationInstance->getAppShortName(). '/';

		// Is the base path valid?
		if (empty($templateBasePath)) {
			// Base path is empty
			throw new UnexpectedValueException(sprintf('[%s:%d] Variable templateBasePath is empty.', $templateInstance->__toString(), __LINE__), self::EXCEPTION_UNEXPECTED_EMPTY_STRING);
		} elseif (!is_string($templateBasePath)) {
			// Is not a string
			throw new UnexpectedValueException(sprintf('[%s:%d] %s is not a string with a base path.', $templateInstance->__toString(), __LINE__, $templateBasePath), self::EXCEPTION_INVALID_STRING);
		} elseif (!is_dir($templateBasePath)) {
			// Is not a path
			throw new InvalidDirectoryException(array($templateInstance, $templateBasePath), self::EXCEPTION_INVALID_PATH_NAME);
		} elseif (!is_readable($templateBasePath)) {
			// Is not readable
			throw new BasePathReadProtectedException(array($templateInstance, $templateBasePath), self::EXCEPTION_READ_PROTECED_PATH);
		}

		// Set the base path
		$templateInstance->setTemplateBasePath($templateBasePath);

		// Set template extensions
		$templateInstance->setRawTemplateExtension($templateInstance->getConfigInstance()->getConfigEntry('raw_template_extension'));
		$templateInstance->setCodeTemplateExtension($templateInstance->getConfigInstance()->getConfigEntry('menu_template_extension'));

		// Absolute output path for compiled templates
		$templateInstance->setCompileOutputPath(sprintf('%s%s/',
			$templateBasePath,
			$templateInstance->getConfigInstance()->getConfigEntry('compile_output_path')
		));

		// Set the menu instance
		$templateInstance->setMenuInstance($menuInstance);

		// Init a variable stacker
		$stackInstance = ObjectFactory::createObjectByConfiguredName('menu_stacker_class');

		// Set it
		$templateInstance->setStackInstance($stackInstance);

		// Return the prepared instance
		return $templateInstance;
	}

	/**
	 * Load a specified menu template into the engine
	 *
	 * @param	$template	The menu template we shall load which is
	 *						located in 'menu' by default
	 * @return	void
	 */
	public function loadMenuTemplate ($template) {
		// Set template type
		$this->setTemplateType($this->getConfigInstance()->getConfigEntry('menu_template_type'));

		// Load the special template
		$this->loadTemplate($template);
	}

	/**
	 * Getter for current main node
	 *
	 * @return	$currMainNode	Current main node
	 */
	public final function getCurrMainNode () {
		return $this->curr['main_node'];
	}

	/**
	 * Setter for current main node
	 *
	 * @param	$element		Element name to set as current main node
	 * @return	$currMainNode	Current main node
	 */
	private final function setCurrMainNode ($element) {
		$this->curr['main_node'] = (string) $element;
	}

	/**
	 * Getter for main node array
	 *
	 * @return	$mainNodes	Array with valid main node names
	 */
	public final function getMainNodes () {
		return $this->mainNodes;
	}

	/**
	 * Getter for sub node array
	 *
	 * @return	$subNodes	Array with valid sub node names
	 */
	public final function getSubNodes () {
		return $this->subNodes;
	}

	/**
	 * Handles the start element of an XML resource
	 *
	 * @param	$resource		XML parser resource (currently ignored)
	 * @param	$element		The element we shall handle
	 * @param	$attributes		All attributes
	 * @return	void
	 * @throws	InvalidXmlNodeException		If an unknown/invalid XML node name was found
	 */
	public function startElement ($resource, $element, array $attributes) {
		// Initial method name which will never be called...
		$methodName = 'initMenu';

		// Make the element name lower-case
		$element = strtolower($element);

		// Is the element a main node?
		//* DEBUG: */ echo "START: &gt;".$element."&lt;<br />\n";
		if (in_array($element, $this->getMainNodes())) {
			// Okay, main node found!
			$methodName = 'start' . self::convertToClassName($element);

			// Set it
			$this->setCurrMainNode($element);
		} elseif (in_array($element, $this->getSubNodes())) {
			// Sub node found
			$methodName = 'start' . self::convertToClassName($element);
		} elseif ($element != 'menu') {
			// Invalid node name found
			throw new InvalidXmlNodeException(array($this, $element, $attributes), XmlParser::EXCEPTION_XML_NODE_UNKNOWN);
		}

		// Call method
		//* DEBUG: */ echo "call: ".$methodName."<br />\n";
		call_user_func_array(array($this, $methodName), $attributes);
	}

	/**
	 * Ends the main or sub node by sending out the gathered data
	 *
	 * @param	$resource	An XML resource pointer (currently ignored)
	 * @param	$nodeName	Name of the node we want to finish
	 * @return	void
	 * @throws	XmlNodeMismatchException	If current main node mismatches the closing one
	 */
	public function finishElement ($resource, $nodeName) {
		// Make all lower-case
		$nodeName = strtolower($nodeName);

		// Does this match with current main node?
		//* DEBUG: */ echo "END: &gt;".$nodeName."&lt;<br />\n";
		if (($nodeName != $this->getCurrMainNode()) && (in_array($nodeName, $this->getMainNodes()))) {
			// Did not match!
			throw new XmlNodeMismatchException (array($this, $nodeName, $this->getCurrMainNode()), XmlParser::EXCEPTION_XML_NODE_MISMATCH);
		} // END - if

		// Construct method name
		$methodName = 'finish' . self::convertToClassName($nodeName);

		// Call the corresponding method
		//* DEBUG: */ echo "call: ".$methodName."<br />\n";
		call_user_func_array(array($this, $methodName), array());
	}

	/**
	 * Currently not used
	 *
	 * @param	$resource		XML parser resource (currently ignored)
	 * @param	$characters		Characters to handle
	 * @return	void
	 * @todo	Find something useful with this!
	 */
	public function characterHandler ($resource, $characters) {
		// Trim all spaces away
		$characters = trim($characters);

		// Is this string empty?
		if (empty($characters)) {
			// Then skip it silently
			return;
		} // END - if

		// Assign the found characters to variable and use the last entry from
		// stack as the name
		parent::assignVariable($this->getStackInstance()->getNamed('current_node'), $characters);
	}

	/**
	 * Handles the template dependency for given node
	 *
	 * @param	$node					The node we should load a dependency template
	 * @param	$templateDependency		A template to load to satisfy dependencies
	 * @return	void
	 */
	private function handleTemplateDependency ($node, $templateDependency) {
		// Is the template dependency set?
		if ((!empty($templateDependency)) && (!isset($this->dependencyContent[$node]))) {
			// Get a temporay menu template instance
			$templateInstance = ObjectFactory::createObjectByConfiguredName('menu_template_class', array($this->getMenuInstance()));

			// Then load it
			$templateInstance->loadMenuTemplate($templateDependency);

			// Parse the XML content
			$templateInstance->renderXmlContent();

			// Save the parsed raw content in our dependency array
			$this->dependencyContent[$node] = $templateInstance->getRawTemplateData();
		} // END - if
	}

	/**
	 * Intializes the menu
	 *
	 * @param	$templateDependency		A template to load to satisfy dependencies
	 * @return	void
	 * @todo	Add cache creation here
	 */
	private function initMenu ($templateDependency = '') {
		// Get web template engine
		$this->setTemplateInstance(ObjectFactory::createObjectByConfiguredName('html_template_class', array(Registry::getRegistry()->getInstance('app'))));

		// Handle the dependency template
		$this->handleTemplateDependency('menu', $templateDependency);

		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'menu');
	}

	/**
	 * Starts the menu entries
	 *
	 * @param	$templateDependency		A template to load to satisfy dependencies
	 * @return	void
	 */
	private function startEntryList () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'entry-list');
	}

	/**
	 * Starts the menu block header
	 *
	 * @return	void
	 */
	private function startBlockHeader () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'block-header');
	}

	/**
	 * Starts the menu block footer
	 *
	 * @return	void
	 */
	private function startBlockFooter () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'block-footer');
	}

	/**
	 * Starts the menu property 'block-list'
	 *
	 * @return	void
	 */
	private function startBlockList () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'block-list');
	}

	/**
	 * Starts the menu property 'block'
	 *
	 * @return	void
	 */
	private function startBlock () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'block');
	}

	/**
	 * Starts the menu property 'title'
	 *
	 * @return	void
	 */
	private function startTitle () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'title');
	}

	/**
	 * Starts the menu property 'title-id'
	 *
	 * @return	void
	 */
	private function startTitleId () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'title-id');
	}

	/**
	 * Starts the menu property 'title-class'
	 *
	 * @return	void
	 */
	private function startTitleClass () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'title-class');
	}

	/**
	 * Starts the menu property 'title-text'
	 *
	 * @return	void
	 */
	private function startTitleText () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'title-text');
	}

	/**
	 * Starts the menu property 'entry'
	 *
	 * @return	void
	 */
	private function startEntry () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'entry');
	}

	/**
	 * Starts the menu property 'entry-id'
	 *
	 * @return	void
	 */
	private function startEntryId () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'entry-id');
	}

	/**
	 * Starts the menu property 'anchor'
	 *
	 * @return	void
	 */
	private function startAnchor () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'anchor');
	}

	/**
	 * Starts the menu property 'anchor-id'
	 *
	 * @return	void
	 */
	private function startAnchorId () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'anchor-id');
	}

	/**
	 * Starts the menu property 'anchor-text'
	 *
	 * @return	void
	 */
	private function startAnchorText () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'anchor-text');
	}

	/**
	 * Starts the menu property 'anchor-title'
	 *
	 * @return	void
	 */
	private function startAnchorTitle () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'anchor-title');
	}

	/**
	 * Starts the menu property 'anchor-href'
	 *
	 * @return	void
	 */
	private function startAnchorHref () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'anchor-href');
	}

	/**
	 * Starts the menu property 'footer-id'
	 *
	 * @return	void
	 */
	private function startFooterId () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'footer-id');
	}

	/**
	 * Starts the menu property 'footer-class'
	 *
	 * @return	void
	 */
	private function startFooterClass () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'footer-class');
	}

	/**
	 * Starts the menu property 'footer-text'
	 *
	 * @return	void
	 */
	private function startFooterText () {
		// Push the node name on the stacker
		$this->getStackInstance()->pushNamed('current_node', 'footer-text');
	}

	/**
	 * Finishes the title node by added another template to the menu
	 *
	 * @return	void
	 */
	private function finishTitle () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the title-id node by
	 *
	 * @return	void
	 */
	private function finishTitleId () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the title-class node
	 *
	 * @return	void
	 */
	private function finishTitleClass () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the title-class node
	 *
	 * @return	void
	 */
	private function finishTitleText () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the footer-text node
	 *
	 * @return	void
	 */
	private function finishFooterText () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the footer-class node
	 *
	 * @return	void
	 */
	private function finishFooterClass () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the footer-id node
	 *
	 * @return	void
	 */
	private function finishFooterId () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the anchor-href node
	 *
	 * @return	void
	 */
	private function finishAnchorHref () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the anchor-title node
	 *
	 * @return	void
	 */
	private function finishAnchorTitle () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the anchor-text node
	 *
	 * @return	void
	 */
	private function finishAnchorText () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the anchor-id node
	 *
	 * @return	void
	 */
	private function finishAnchorId () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the anchor node
	 *
	 * @return	void
	 */
	private function finishAnchor () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the entry-id node
	 *
	 * @return	void
	 */
	private function finishEntryId () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the entry node
	 *
	 * @return	void
	 */
	private function finishEntry () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');

		// Render this menu entry
		$this->renderMenuEntry();
	}

	/**
	 * Finishes the block node
	 *
	 * @return	void
	 */
	private function finishBlock () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');

		// Render this menu block
		$this->renderMenuBlock();
	}

	/**
	 * Finishes the block-list node
	 *
	 * @return	void
	 */
	private function finishBlockList () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the menu entries
	 *
	 * @return	void
	 */
	private function finishEntryList () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the menu block header
	 *
	 * @return	void
	 */
	private function finishBlockHeader () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the menu block footer
	 *
	 * @return	void
	 */
	private function finishBlockFooter () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Finishes the menu
	 *
	 * @return	void
	 */
	private function finishMenu () {
		// Pop the last entry
		$this->getStackInstance()->popNamed('current_node');
	}

	/**
	 * Renders this menu entry, as every block all variables got overwritten
	 * with data from next entry.
	 *
	 * @return	void
	 */
	private function renderMenuEntry () {
		// Prepare template engine
		$templateInstance = $this->prepareTemplateInstance();

		// Load menu entry template
		$templateInstance->loadCodeTemplate('menu_entry');

		// Copy all variables over to it
		foreach ($this->menuEntryVariables as $variableName) {
			// Copy variable
			$variableValue = $this->readVariable($variableName);

			// Is the key 'anchor-href'?
			if ($variableName == 'anchor-href') {
				// Expand variable with URL then
				$variableValue = '{?base_url?}/' . $variableValue;
			} // END - if

			// ... into the instance
			$templateInstance->assignVariable($variableName, $variableValue);
		} // END - foreach

		// Compile template + variables
		$templateInstance->compileTemplate();
		$templateInstance->compileVariables();

		// Remember it here
		$this->menuEntries[$this->readVariable('entry_id')] = $templateInstance->getRawTemplateData();
	}

	/**
	 * Renders this menu block, as next block all data is overwritten with
	 * next block.
	 *
	 * @return	void
	 */
	private function renderMenuBlock () {
		// Init block content
		$blockContent = implode('', $this->menuEntries);

		// Prepare template engine
		$templateInstance = $this->prepareTemplateInstance();

		// Load menu entry template
		$templateInstance->loadCodeTemplate('menu_block');

		// Copy all variables over to it
		foreach ($this->menuBlockVariables as $variableName) {
			// Copy variable
			$variableValue = $this->readVariable($variableName);

			// ... into the instance
			$templateInstance->assignVariable($variableName, $variableValue);
		} // END - foreach

		// Assign block content
		$templateInstance->assignVariable('block_content', $blockContent);

		// Compile template + variables
		$templateInstance->compileTemplate();
		$templateInstance->compileVariables();

		// Remember it here
		array_push($this->menuBlocks, $templateInstance->getRawTemplateData());

		// Reset rendered menu entries array
		$this->menuEntries = array();
	}

	/**
	 * "Getter" for menu content
	 *
	 * @return	$menuContent	Returned menu content
	 */
	public function getMenuContent () {
		// Implode menuBlocks
		$menuContent = implode('', $this->menuBlocks);

		// Clean variable
		$this->menuBlocks = array();

		// And return it
		return $menuContent;
	}

	/**
	 * Getter for menu cache file instance
	 *
	 * @return	$fileInstance	Full-qualified file name of the menu cache
	 */
	public function getMenuCacheFile () {
		// Get the application instance from registry
		$applicationInstance = Registry::getRegistry()->getInstance('app');

		// Get the file instance ready
		$fileInstance = new SplFileInfo(sprintf('%s%smenus/_cache/%s.%s',
			$this->getConfigInstance()->getConfigEntry('application_base_path'),
			$applicationInstance->getAppShortName(),
			md5(
				$this->getMenuInstance()->getMenuName() . ':' .
				$this->__toString() . ':' .
				$this->getMenuInstance()->__toString()
			),
			$this->getMenuInstance()->getMenuType()
		));

		// Return it
		return $fileInstance;
	}

}