<?php

namespace Transbank\Onepay;

 /**
  * Class Item.
  */
 class Item implements \JsonSerializable
 {
     private $description;
     private $quantity;
     private $amount; /* int */
     private $additionalData;
     private $expire;

     /**
      * Set Description for an instance of Item.
      */
     public function __construct(
         $description,
         $quantity,
         $amount,
         $additionalData = null,
         $expire = 0
     ) {
         $this->setDescription($description);
         $this->setQuantity($quantity);
         $this->setAmount($amount);
         $this->setAdditionalData($additionalData);
         $this->setExpire($expire);
     }

     public function jsonSerialize()
     {
         return get_object_vars($this);
     }

     public function setDescription($description)
     {
         if (!is_string($description)) {
             throw new \Exception('Description is not a string');
         }
         $this->description = $description;
     }

     /**
      * Get Description for an instance of Item.
      */
     public function getDescription()
     {
         return $this->description;
     }

     /**
      * Set the quantity for an instance of Item.
      */
     public function setQuantity($quantity)
     {
         if (!is_integer($quantity)) {
             throw new \Exception('quantity must be an Integer');
         }
         if ($quantity < 0) {
             throw new \Exception('quantity cannot be less than zero');
         }
         $this->quantity = $quantity;
     }

     /**
      * Get the quantity for an instance of Item.
      */
     public function getQuantity()
     {
         return $this->quantity;
     }

     /**
      * Set the quantity for an instance of Item.
      */
     public function setAmount($amount)
     {
         if (!is_integer($amount)) {
             throw new \Exception('amount must be an Integer');
         }
         $this->amount = $amount;
     }

     /**
      * Get the quantity for an instance of Item.
      */
     public function getAmount()
     {
         return $this->amount;
     }

     /**
      * Set the additional data for an instance of Item.
      */
     public function setAdditionalData($additionalData)
     {
         if (is_null($additionalData)) {
             $additionalData = '';
         }
         if (!is_string($additionalData)) {
             throw new \Exception('Additional Data must be a String');
         }
         $this->additionalData = $additionalData;
     }

     /**
      * Get the additional data for an instance of Item.
      */
     public function getAdditionalData()
     {
         return $this->additionalData;
     }

     /**
      * Set expire for an instance of Item.
      */
     public function setExpire($expire)
     {
         if (!is_long($expire)) {
             throw new \Exception('expire must be a Long');
         }
         $this->expire = $expire;
     }

     /**
      * Get expire for an instance of Item.
      */
     public function getExpire()
     {
         return $this->expire;
     }

     /**
      * Takes a associative array (or JSON string)
      * with the following shape:
      * $item = ("description" => "MANDATORY - A string",
      *          "amount" => "MANDATORY - A number",
      *          "quantity" => "MANDATORY - A number",
      *          "additionalData" => "OPTIONAL - A string",
      *          "expire" => "OPTIONAL - A number")
      *  and creates a new instance of Item.
      */
     public static function fromJSON($item)
     {
         if (is_string($item)) {
             $item = json_decode($item, true);
         }
         if (!is_array($item)) {
             throw new \Exception('Item must be a JSON string or an associative array that is transformable to an associative array using json_decode');
         }
         /**
          * Define default values.
          */
         $defaultValues = ['amount' => null,
             'description'          => null,
             'quantity'             => null,
             'expire'               => 0,
             'additionalData'       => null, ];

         /**
          * Have the default values for all keys, event if they are not included
          * in the $item associative array originally.
          */
         $item = array_merge($defaultValues, $item);

         return new Item(
             $item['description'],
             $item['quantity'],
             $item['amount'],
             $item['additionalData'],
             $item['expire']
         );
     }
 }