<?php

namespace common\behaviors;

use yii\base\Behavior;
use yii\db\ActiveRecord;
use yii\db\AfterSaveEvent;
use frontend\events\ChangedOrderStatusEvent;
use yii\base\ErrorException;
use yii\base\InvalidConfigException;

/**
 * The behavior triggers a status change event
 */
class StatusEventsBehavior extends Behavior
{
    /**
     * Attribute name
     *
     * @var string
     */
    public $attribute;

    /**
     * Status name
     *
     * @var string|callable
     */
    public $statusName;

    public function events()
    {
        return [
            ActiveRecord::EVENT_AFTER_INSERT => 'handle',
            ActiveRecord::EVENT_AFTER_UPDATE => 'handle',
        ];
    }

    public function handle(AfterSaveEvent $event)
    {
        if (!$this->statusName || !$this->attribute) {
            throw new InvalidConfigException(Yii::t('common/behaviors/status-events-behavior', 'Attribute and status name must be specified.'));
        }

        if (!$this->whetherTheStatusHasBeenChanged($event)) {
            return;
        }

        $statusName = $this->getStatusName();
        if (!$statusName) {
            return;
        }

        $event = new ChangedOrderStatusEvent([
            'order' => $this->owner,
            'statusName' => $statusName
        ]);

        $this->owner->trigger($statusName, $event);
    }

    protected function whetherTheStatusHasBeenChanged(AfterSaveEvent $event)
    {
        $newOrderStatusId = $this->owner->getAttribute($this->attribute);
        if (!$newOrderStatusId) {
            return false;
        }

        if (!$event->changedAttributes || !array_key_exists($this->attribute, $event->changedAttributes)) {
            return false;
        }

        if ($newOrderStatusId === $event->changedAttributes[$this->attribute]) {
            return false;
        }

        return true;
    }

    protected function getStatusName()
    {
        if (is_callable($this->statusName)) {
            $statusName = call_user_func($this->statusName, $this->owner);
        } elseif (is_string($this->statusName)) {
            $statusName = $this->statusName;
        } else {
            throw new ErrorException(Yii::t('common/behaviors/status-events-behavior', 'Status name must be string or callable.'));
        }

        return $statusName;
    }
}