<?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;

/**
 * Collapse renders an accordion bootstrap javascript component.
 *
 * For example:
 *
 * ```php
 * echo Collapse::widget([
 * 'items' => [
 * // equivalent to the above
 * [
 * 'label' => 'Collapsible Group Item #1',
 * 'content' => 'Anim pariatur cliche...',
 * // open its content by default
 * 'contentOptions' => ['class' => 'in']
 * ],
 * // another group item
 * [
 * 'label' => 'Collapsible Group Item #1',
 * 'content' => 'Anim pariatur cliche...',
 * 'contentOptions' => [...],
 * 'options' => [...],
 * ],
 * // if you want to swap out .panel-body with .list-group, you may use the following
 * [
 * 'label' => 'Collapsible Group Item #1',
 * 'content' => [
 * 'Anim pariatur cliche...',
 * 'Anim pariatur cliche...'
 * ],
 * 'contentOptions' => [...],
 * 'options' => [...],
 * 'footer' => 'Footer' // the footer label in list-group
 * ],
 * ]
 * ]);
 * ```
 *
 * @see http://getbootstrap.com/javascript/#collapse
 * @author Antonio Ramirez <amigo.cobos@gmail.com>
 * @since 2.0
 */
class Collapse extends Widget
{

    /**
     *
     * @var array list of groups in the collapse widget. Each array element represents a single
     *      group with the following structure:
     *     
     *      - label: string, required, the group header label.
     *      - encode: boolean, optional, whether this label should be HTML-encoded. This param will override
     *      global `$this->encodeLabels` param.
     *      - content: array|string|object, required, the content (HTML) of the group
     *      - options: array, optional, the HTML attributes of the group
     *      - contentOptions: optional, the HTML attributes of the group's content
     */
    public $items = [];

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

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

    /**
     * Renders the widget.
     */
    public function run()
    {
        $this->registerPlugin('collapse');
        return implode("\n", [
            Html::beginTag('div', $this->options),
            $this->renderItems(),
            Html::endTag('div')
        ]) . "\n";
    }

    /**
     * Renders collapsible items as specified on [[items]].
     * 
     * @throws InvalidConfigException if label isn't specified
     * @return string the rendering result
     */
    public function renderItems()
    {
        $items = [];
        $index = 0;
        foreach ($this->items as $item) {
            if (!array_key_exists('label', $item)) {
                throw new InvalidConfigException("The 'label' option is required.");
            }
            $header = $item['label'];
            $options = ArrayHelper::getValue($item, 'options', []);
            Html::addCssClass($options, [
                'panel' => 'panel',
                'widget' => 'panel-default'
            ]);
            $items[] = Html::tag('div', $this->renderItem($header, $item, ++ $index), $options);
        }
        
        return implode("\n", $items);
    }

    /**
     * Renders a single collapsible item group
     * 
     * @param string $header
     *            a label of the item group [[items]]
     * @param array $item
     *            a single item from [[items]]
     * @param integer $index
     *            the item index as each item group content must have an id
     * @return string the rendering result
     * @throws InvalidConfigException
     */
    public function renderItem($header, $item, $index)
    {
        if (array_key_exists('content', $item)) {
            $id = $this->options['id'] . '-collapse' . $index;
            $options = ArrayHelper::getValue($item, 'contentOptions', []);
            $options['id'] = $id;
            Html::addCssClass($options, [
                'widget' => 'panel-collapse',
                'collapse' => 'collapse'
            ]);
            
            $encodeLabel = isset($item['encode']) ? $item['encode'] : $this->encodeLabels;
            if ($encodeLabel) {
                $header = Html::encode($header);
            }
            
            $headerToggle = Html::a($header, '#' . $id, [
                'class' => 'collapse-toggle',
                'data-toggle' => 'collapse',
                'data-parent' => '#' . $this->options['id']
            ]) . "\n";
            
            $header = Html::tag('h4', $headerToggle, [
                'class' => 'panel-title'
            ]);
            
            if (is_string($item['content']) || is_object($item['content'])) {
                $content = Html::tag('div', $item['content'], [
                    'class' => 'panel-body'
                ]) . "\n";
            } elseif (is_array($item['content'])) {
                $content = Html::ul($item['content'], [
                    'class' => 'list-group',
                    'itemOptions' => [
                        'class' => 'list-group-item'
                    ],
                    'encode' => false
                ]) . "\n";
                if (isset($item['footer'])) {
                    $content .= Html::tag('div', $item['footer'], [
                        'class' => 'panel-footer'
                    ]) . "\n";
                }
            } else {
                throw new InvalidConfigException('The "content" option should be a string, array or object.');
            }
        } else {
            throw new InvalidConfigException('The "content" option is required.');
        }
        $group = [];
        
        $group[] = Html::tag('div', $header, [
            'class' => 'panel-heading'
        ]);
        $group[] = Html::tag('div', $content, $options);
        
        return implode("\n", $group);
    }
}
