<?php

/**
 * @package KantPHP
 * @author  Zhenqiang Zhang <zhenqiang.zhang@hotmail.com>
 * @copyright (c) KantPHP Studio, All rights reserved.
 * @license http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 */
namespace Kant\Bootstrap;

use Kant\Exception\InvalidConfigException;
use Kant\Helper\ArrayHelper;

/**
 * Tabs renders a Tab bootstrap javascript component.
 *
 * For example:
 *
 * ```php
 * echo Tabs::widget([
 * 'items' => [
 * [
 * 'label' => 'One',
 * 'content' => 'Anim pariatur cliche...',
 * 'active' => true
 * ],
 * [
 * 'label' => 'Two',
 * 'content' => 'Anim pariatur cliche...',
 * 'headerOptions' => [...],
 * 'options' => ['id' => 'myveryownID'],
 * ],
 * [
 * 'label' => 'Example',
 * 'url' => 'http://www.example.com',
 * ],
 * [
 * 'label' => 'Dropdown',
 * 'items' => [
 * [
 * 'label' => 'DropdownA',
 * 'content' => 'DropdownA, Anim pariatur cliche...',
 * ],
 * [
 * 'label' => 'DropdownB',
 * 'content' => 'DropdownB, Anim pariatur cliche...',
 * ],
 * ],
 * ],
 * ],
 * ]);
 * ```
 *
 * @see http://getbootstrap.com/javascript/#tabs
 * @author Antonio Ramirez <amigo.cobos@gmail.com>
 * @since 2.0
 */
class Tabs extends Widget
{

    /**
     *
     * @var array list of tabs in the tabs widget. Each array element represents a single
     *      tab with the following structure:
     *     
     *      - label: string, required, the tab header label.
     *      - encode: boolean, optional, whether this label should be HTML-encoded. This param will override
     *      global `$this->encodeLabels` param.
     *      - headerOptions: array, optional, the HTML attributes of the tab header.
     *      - linkOptions: array, optional, the HTML attributes of the tab header link tags.
     *      - content: string, optional, the content (HTML) of the tab pane.
     *      - url: string, optional, an external URL. When this is specified, clicking on this tab will bring
     *      the browser to this URL. This option is available since version 2.0.4.
     *      - options: array, optional, the HTML attributes of the tab pane container.
     *      - active: boolean, optional, whether this item tab header and pane should be active. If no item is marked as
     *      'active' explicitly - the first one will be activated.
     *      - visible: boolean, optional, whether the item tab header and pane should be visible or not. Defaults to true.
     *      - items: array, optional, can be used instead of `content` to specify a dropdown items
     *      configuration array. Each item can hold three extra keys, besides the above ones:
     *      * active: boolean, optional, whether the item tab header and pane should be visible or not.
     *      * content: string, required if `items` is not set. The content (HTML) of the tab pane.
     *      * contentOptions: optional, array, the HTML attributes of the tab content container.
     */
    public $items = [];

    /**
     *
     * @var array list of HTML attributes for the item container tags. This will be overwritten
     *      by the "options" set in individual [[items]]. The following special options are recognized:
     *     
     *      - tag: string, defaults to "div", the tag name of the item container tags.
     *     
     * @see \Kant\Helper\Html::renderTagAttributes() for details on how attributes are being rendered.
     */
    public $itemOptions = [];

    /**
     *
     * @var array list of HTML attributes for the header container tags. This will be overwritten
     *      by the "headerOptions" set in individual [[items]].
     * @see \Kant\Helper\Html::renderTagAttributes() for details on how attributes are being rendered.
     */
    public $headerOptions = [];

    /**
     *
     * @var array list of HTML attributes for the tab header link tags. This will be overwritten
     *      by the "linkOptions" set in individual [[items]].
     * @see \Kant\Helper\Html::renderTagAttributes() for details on how attributes are being rendered.
     */
    public $linkOptions = [];

    /**
     *
     * @var boolean whether the labels for header items should be HTML-encoded.
     */
    public $encodeLabels = true;

    /**
     *
     * @var string specifies the Bootstrap tab styling.
     */
    public $navType = 'nav-tabs';

    /**
     *
     * @var boolean whether to render the `tab-content` container and its content. You may set this property
     *      to be false so that you can manually render `tab-content` yourself in case your tab contents are complex.
     * @since 2.0.1
     */
    public $renderTabContent = true;

    /**
     * Initializes the widget.
     */
    public function init()
    {
        parent::init();
        Html::addCssClass($this->options, [
            'widget' => 'nav',
            $this->navType
        ]);
    }

    /**
     * Renders the widget.
     */
    public function run()
    {
        $this->registerPlugin('tab');
        return $this->renderItems();
    }

    /**
     * Renders tab items as specified on [[items]].
     * 
     * @return string the rendering result.
     * @throws InvalidConfigException.
     */
    protected function renderItems()
    {
        $headers = [];
        $panes = [];
        
        if (!$this->hasActiveTab() && ! empty($this->items)) {
            $this->items[0]['active'] = true;
        }
        
        foreach ($this->items as $n => $item) {
            if (!ArrayHelper::remove($item, 'visible', true)) {
                continue;
            }
            if (!array_key_exists('label', $item)) {
                throw new InvalidConfigException("The 'label' option is required.");
            }
            $encodeLabel = isset($item['encode']) ? $item['encode'] : $this->encodeLabels;
            $label = $encodeLabel ? Html::encode($item['label']) : $item['label'];
            $headerOptions = array_merge($this->headerOptions, ArrayHelper::getValue($item, 'headerOptions', []));
            $linkOptions = array_merge($this->linkOptions, ArrayHelper::getValue($item, 'linkOptions', []));
            
            if (isset($item['items'])) {
                $label .= ' <b class="caret"></b>';
                Html::addCssClass($headerOptions, [
                    'widget' => 'dropdown'
                ]);
                
                if ($this->renderDropdown($n, $item['items'], $panes)) {
                    Html::addCssClass($headerOptions, 'active');
                }
                
                Html::addCssClass($linkOptions, [
                    'widget' => 'dropdown-toggle'
                ]);
                if (!isset($linkOptions['data-toggle'])) {
                    $linkOptions['data-toggle'] = 'dropdown';
                }
                $header = Html::a($label, "#", $linkOptions) . "\n" . Dropdown::widget([
                    'items' => $item['items'],
                    'clientOptions' => false,
                    'view' => $this->getView()
                ]);
            } else {
                $options = array_merge($this->itemOptions, ArrayHelper::getValue($item, 'options', []));
                $options['id'] = ArrayHelper::getValue($options, 'id', $this->options['id'] . '-tab' . $n);
                
                Html::addCssClass($options, [
                    'widget' => 'tab-pane'
                ]);
                if (ArrayHelper::remove($item, 'active')) {
                    Html::addCssClass($options, 'active');
                    Html::addCssClass($headerOptions, 'active');
                }
                
                if (isset($item['url'])) {
                    $header = Html::a($label, $item['url'], $linkOptions);
                } else {
                    if (!isset($linkOptions['data-toggle'])) {
                        $linkOptions['data-toggle'] = 'tab';
                    }
                    $header = Html::a($label, '#' . $options['id'], $linkOptions);
                }
                
                if ($this->renderTabContent) {
                    $tag = ArrayHelper::remove($options, 'tag', 'div');
                    $panes[] = Html::tag($tag, isset($item['content']) ? $item['content'] : '', $options);
                }
            }
            
            $headers[] = Html::tag('li', $header, $headerOptions);
        }
        
        return Html::tag('ul', implode("\n", $headers), $this->options) . ($this->renderTabContent ? "\n" . Html::tag('div', implode("\n", $panes), [
            'class' => 'tab-content'
        ]) : '');
    }

    /**
     *
     * @return boolean if there's active tab defined
     */
    protected function hasActiveTab()
    {
        foreach ($this->items as $item) {
            if (isset($item['active']) && $item['active'] === true) {
                return true;
            }
        }
        
        return false;
    }

    /**
     * Normalizes dropdown item options by removing tab specific keys `content` and `contentOptions`, and also
     * configure `panes` accordingly.
     * 
     * @param string $itemNumber
     *            number of the item
     * @param array $items
     *            the dropdown items configuration.
     * @param array $panes
     *            the panes reference array.
     * @return boolean whether any of the dropdown items is `active` or not.
     * @throws InvalidConfigException
     */
    protected function renderDropdown($itemNumber, &$items, &$panes)
    {
        $itemActive = false;
        
        foreach ($items as $n => &$item) {
            if (is_string($item)) {
                continue;
            }
            if (isset($item['visible']) && ! $item['visible']) {
                continue;
            }
            if (!array_key_exists('content', $item)) {
                throw new InvalidConfigException("The 'content' option is required.");
            }
            
            $content = ArrayHelper::remove($item, 'content');
            $options = ArrayHelper::remove($item, 'contentOptions', []);
            Html::addCssClass($options, [
                'widget' => 'tab-pane'
            ]);
            if (ArrayHelper::remove($item, 'active')) {
                Html::addCssClass($options, 'active');
                Html::addCssClass($item['options'], 'active');
                $itemActive = true;
            }
            
            $options['id'] = ArrayHelper::getValue($options, 'id', $this->options['id'] . '-dd' . $itemNumber . '-tab' . $n);
            $item['url'] = '#' . $options['id'];
            if (!isset($item['linkOptions']['data-toggle'])) {
                $item['linkOptions']['data-toggle'] = 'tab';
            }
            $panes[] = Html::tag('div', $content, $options);
            
            unset($item);
        }
        
        return $itemActive;
    }
}
