<?php

/**
 * @copyright Copyright &copy; Kartik Visweswaran, Krajee.com, 2014
 * @package yii2-widgets
 * @subpackage yii2-widget-sidenav
 * @version 1.0.0
 */
namespace kartik\sidenav;

use Yii;
use yii\base\InvalidConfigException;
use yii\helpers\Html;
use yii\helpers\Url;
use yii\helpers\ArrayHelper;

/**
 * A custom extended side navigation menu extending Yii Menu
 *
 * For example:
 *
 * ```php
 * echo SideNav::widget([
 * 'items' => [
 * [
 * 'url' => ['/site/index'],
 * 'label' => 'Home',
 * 'icon' => 'home'
 * ],
 * [
 * 'url' => ['/site/about'],
 * 'label' => 'About',
 * 'icon' => 'info-sign',
 * 'items' => [
 * ['url' => '#', 'label' => 'Item 1'],
 * ['url' => '#', 'label' => 'Item 2'],
 * ],
 * ],
 * ],
 * ]);
 * ```
 *
 * @author Kartik Visweswaran <kartikv2@gmail.com>
 */
class SideNav extends \yii\widgets\Menu {
	
	/**
	 * Panel contextual states
	 */
	const TYPE_DEFAULT = 'default';
	const TYPE_PRIMARY = 'primary';
	const TYPE_INFO = 'info';
	const TYPE_SUCCESS = 'success';
	const TYPE_DANGER = 'danger';
	const TYPE_WARNING = 'warning';
	
	/**
	 *
	 * @var string the menu container style. This is one of the bootstrap panel
	 *      contextual state classes. Defaults to `default`.
	 * @see http://getbootstrap.com/components/#panels
	 */
	public $type = self::TYPE_DEFAULT;
	
	/**
	 *
	 * @var string prefix for the icon in [[items]]. This string will be prepended
	 *      before the icon name to get the icon CSS class. This defaults to `glyphicon glyphicon-`
	 *      for usage with glyphicons available with Bootstrap.
	 */
	public $iconPrefix = 'glyphicon glyphicon-';
	
	/**
	 *
	 * @var array string/boolean the sidenav heading. This is not HTML encoded
	 *      When set to false or null, no heading container will be displayed.
	 */
	public $heading = false;
	
	/**
	 *
	 * @var array options for the sidenav heading
	 */
	public $headingOptions = [ ];
	
	/**
	 *
	 * @var array options for the sidenav container
	 */
	public $containerOptions = [ ];
	
	/**
	 *
	 * @var string indicator for a menu sub-item
	 */
	public $indItem = '&raquo; ';
	
	/**
	 *
	 * @var string indicator for a opened sub-menu
	 */
	public $indMenuOpen = '<i class="indicator glyphicon glyphicon-chevron-down"></i>';
	
	/**
	 *
	 * @var string indicator for a closed sub-menu
	 */
	public $indMenuClose = '<i class="indicator glyphicon glyphicon-chevron-right"></i>';
	
	/**
	 *
	 * @var array list of sidenav menu items. Each menu item should be an array of the following structure:
	 *     
	 *      - label: string, optional, specifies the menu item label. When [[encodeLabels]] is true, the label
	 *      will be HTML-encoded. If the label is not specified, an empty string will be used.
	 *      - icon: string, optional, specifies the glyphicon name to be placed before label.
	 *      - url: string or array, optional, specifies the URL of the menu item. It will be processed by [[Url::to]].
	 *      When this is set, the actual menu item content will be generated using [[linkTemplate]];
	 *      - visible: boolean, optional, whether this menu item is visible. Defaults to true.
	 *      - items: array, optional, specifies the sub-menu items. Its format is the same as the parent items.
	 *      - active: boolean, optional, whether this menu item is in active state (currently selected).
	 *      If a menu item is active, its CSS class will be appended with [[activeCssClass]].
	 *      If this option is not set, the menu item will be set active automatically when the current request
	 *      is triggered by [[url]]. For more details, please refer to [[isItemActive()]].
	 *      - template: string, optional, the template used to render the content of this menu item.
	 *      The token `{url}` will be replaced by the URL associated with this menu item,
	 *      and the token `{label}` will be replaced by the label of the menu item.
	 *      If this option is not set, [[linkTemplate]] will be used instead.
	 *      - options: array, optional, the HTML attributes for the menu item tag.
	 *     
	 */
	public $items;
	
	/**
	 * Allowed panel stypes
	 */
	private static $_validTypes = [ 
			self::TYPE_DEFAULT,
			self::TYPE_PRIMARY,
			self::TYPE_INFO,
			self::TYPE_SUCCESS,
			self::TYPE_DANGER,
			self::TYPE_WARNING 
	];
	public function init() {
		parent::init ();
		SideNavAsset::register ( $this->getView () );
		$this->activateParents = true;
		$this->submenuTemplate = "\n<ul class='nav nav-pills nav-stacked'>\n{items}\n</ul>\n";
		$this->linkTemplate = '<a href="{url}">{icon}{label}</a>';
		$this->labelTemplate = '{icon}{label}';
		$this->markTopItems ();
		Html::addCssClass ( $this->options, 'nav nav-pills nav-stacked kv-sidenav' );
	}
	
	/**
	 * Renders the side navigation menu.
	 * with the heading and panel containers
	 */
	public function run() {
		$heading = '';
		if (isset ( $this->heading ) && $this->heading != '') {
			Html::addCssClass ( $this->headingOptions, 'panel-heading' );
			$heading = Html::tag ( 'div', '<h3 class="panel-title">' . $this->heading . '</h3>', $this->headingOptions );
		}
		$body = Html::tag ( 'div', $this->renderMenu (), [ 
				'class' => 'table' 
		] );
		$type = in_array ( $this->type, self::$_validTypes ) ? $this->type : self::TYPE_DEFAULT;
		Html::addCssClass ( $this->containerOptions, "panel panel-{$type}" );
		echo Html::tag ( 'div', $heading . $body, $this->containerOptions );
	}
	
	/**
	 * Renders the main menu
	 */
	protected function renderMenu() {
		if ($this->route === null && Yii::$app->controller !== null) {
			$this->route = Yii::$app->controller->getRoute ();
		}
		if ($this->params === null) {
			$this->params = $_GET;
		}
		$items = $this->normalizeItems ( $this->items, $hasActiveChild );
		$options = $this->options;
		$tag = ArrayHelper::remove ( $options, 'tag', 'ul' );
		
		return Html::tag ( $tag, $this->renderItems ( $items ), $options );
	}
	
	/**
	 * Marks each topmost level item which is not a submenu
	 */
	protected function markTopItems() {
		$items = [ ];
		foreach ( $this->items as $item ) {
			if (empty ( $item ['items'] )) {
				$item ['top'] = true;
			}
			$items [] = $item;
		}
		$this->items = $items;
	}
	
	/**
	 * Renders the content of a side navigation menu item.
	 *
	 * @param array $item
	 *        	the menu item to be rendered. Please refer to [[items]] to see what data might be in the item.
	 * @return string the rendering result
	 * @throws InvalidConfigException
	 */
	protected function renderItem($item) {
		$this->validateItems ( $item );
		$template = ArrayHelper::getValue ( $item, 'template', $this->linkTemplate );
		$url = Url::to ( ArrayHelper::getValue ( $item, 'url', '#' ) );
		if (empty ( $item ['top'] )) {
			if (empty ( $item ['items'] )) {
				$template = str_replace ( '{icon}', $this->indItem . '{icon}', $template );
			} else {
				$template = isset ( $item ['template'] ) ? $item ['template'] : '<a href="{url}" class="kv-toggle">{icon}{label}</a>';
				$openOptions = ($item ['active']) ? [ 
						'class' => 'opened' 
				] : [ 
						'class' => 'opened',
						'style' => 'display:none' 
				];
				$closeOptions = ($item ['active']) ? [ 
						'class' => 'closed',
						'style' => 'display:none' 
				] : [ 
						'class' => 'closed' 
				];
				$indicator = Html::tag ( 'span', $this->indMenuOpen, $openOptions ) . Html::tag ( 'span', $this->indMenuClose, $closeOptions );
				$template = str_replace ( '{icon}', $indicator . '{icon}', $template );
			}
		}
		$icon = empty ( $item ['icon'] ) ? '' : '<span class="' . $this->iconPrefix . $item ['icon'] . '"></span> &nbsp;';
		unset ( $item ['icon'], $item ['top'] );
		return strtr ( $template, [ 
				'{url}' => $url,
				'{label}' => $item ['label'],
				'{icon}' => $icon 
		] );
	}
	
	/**
	 * Validates each item for a valid label and url.
	 *
	 * @throws InvalidConfigException
	 */
	protected function validateItems($item) {
		if (! isset ( $item ['label'] )) {
			throw new InvalidConfigException ( "The 'label' option is required." );
		}
	}
}