<?php

namespace x1\dragula;

use Yii;
use yii\helpers\Html;
use yii\helpers\Json;
use yii\helpers\ArrayHelper;
use yii\web\JsExpression;
use yii\web\View;
use yii\helpers\Url;

/**
 *
 *  EXAMPLE
 *  =======
 *
 * <?= \x1\dragula\Dragula::widget([
 *     'containers' => ['#files'],
 *     'options'    => [
 *         'revertOnSpill' => true,
 *     ],
 *     'drop' => new \yii\web\JsExpression('my.dropped'),
 * ]); ?>
 *
 *
 * <script>
 *     var my = {};
 *
 *     my.dropped = function(el, container) {
 *         var c      = $(container);
 *         var items  = c.find('li[data-filename]');
 *         var result = [];
 *         $.each(c.find('li[data-filename]'), function(key, item) {
 *             result.push($(item).data('filename'));
 *         });
 *
 *         console.log('result', result);
 *         // your logic here, e.g. ajax post
 *     }
 * </script>
 *
 */
class Dragula extends \yii\base\Widget {

    public $containers = null;
    public $options    = null;

    // events
    public $drag    = null;
    public $dragend = null;
    public $drop    = null;
    public $cancel  = null;
    public $remove  = null;
    public $shadow  = null;
    public $over    = null;
    public $out     = null;
    public $cloned  = null;

    const EVENTS  = ['drag', 'dragend', 'drop', 'cancel', 'remove', 'shadow', 'over', 'out', 'cloned'];
    const PARAMS2 = ['el', 'container', 'source'];
    const PARAMS  = [
        'drag'    => ['el', 'source'],
        'dragend' => ['el'],
        'drop'    => ['el', 'target', 'source', 'sibling'],
        'cancel'  => self::PARAMS2,
        'remove'  => self::PARAMS2,
        'shadow'  => self::PARAMS2,
        'over'    => self::PARAMS2,
        'out'     => self::PARAMS2,
        'cloned'  => ['clone', 'original', 'type'],
    ];

    public function init() {
        parent::init();

        if ($this->containers == null) {
            throw new \yii\base\InvalidConfigException("`containers` must be set");
        }

        if (!is_array($this->containers))
            $this->containers = [$this->containers];

        foreach ($this->containers as $key => $container) {
            if (!($container instanceof JsExpression)) {
                $this->containers[$key] = new JsExpression(sprintf('document.querySelector(%s)', json_encode($container)));
            }
        }
    }

    public function run() {
        DragulaAsset::register($this->view);

        $events = [];
        foreach (self::EVENTS as $event) {
            if ($this->$event !== null) {
                if ($this->$event instanceof JsExpression) {
                    $events[] = new JsExpression(sprintf('.on("%s", %s)', $event, $this->$event));
                } else {
                    $events[] = new JsExpression(sprintf('.on("%s", function(%s) { %s })', $event, implode(',', self::PARAMS[$event]), $this->$event));
                }
            }
        }

        $this->view->registerJs(sprintf('dragula(%s, %s)%s;', Json::encode($this->containers), Json::encode($this->options), implode('', $events)));
        return null;
    }

}