<?php namespace Illuminate\Support;

use Countable;
use JsonSerializable;
use Illuminate\Contracts\Support\Jsonable;
use Illuminate\Contracts\Support\Arrayable;
use Illuminate\Contracts\Support\MessageProvider;
use Illuminate\Contracts\Support\MessageBag as MessageBagContract;

class MessageBag implements Arrayable, Countable, Jsonable, JsonSerializable, MessageBagContract, MessageProvider  {

	/**
	 * All of the registered messages.
	 *
	 * @var array
	 */
	protected $messages = array();

	/**
	 * Default format for message output.
	 *
	 * @var string
	 */
	protected $format = ':message';

	/**
	 * Create a new message bag instance.
	 *
	 * @param  array  $messages
	 * @return void
	 */
	public function __construct(array $messages = array())
	{
		foreach ($messages as $key => $value)
		{
			$this->messages[$key] = (array) $value;
		}
	}

	/**
	 * Get the keys present in the message bag.
	 *
	 * @return array
	 */
	public function keys()
	{
		return array_keys($this->messages);
	}

	/**
	 * Add a message to the bag.
	 *
	 * @param  string  $key
	 * @param  string  $message
	 * @return $this
	 */
	public function add($key, $message)
	{
		if ($this->isUnique($key, $message))
		{
			$this->messages[$key][] = $message;
		}

		return $this;
	}

	/**
	 * Merge a new array of messages into the bag.
	 *
	 * @param  \Illuminate\Contracts\Support\MessageProvider|array  $messages
	 * @return $this
	 */
	public function merge($messages)
	{
		if ($messages instanceof MessageProvider)
		{
			$messages = $messages->getMessageBag()->getMessages();
		}

		$this->messages = array_merge_recursive($this->messages, $messages);

		return $this;
	}

	/**
	 * Determine if a key and message combination already exists.
	 *
	 * @param  string  $key
	 * @param  string  $message
	 * @return bool
	 */
	protected function isUnique($key, $message)
	{
		$messages = (array) $this->messages;

		return ! isset($messages[$key]) || ! in_array($message, $messages[$key]);
	}

	/**
	 * Determine if messages exist for a given key.
	 *
	 * @param  string  $key
	 * @return bool
	 */
	public function has($key = null)
	{
		return $this->first($key) !== '';
	}

	/**
	 * Get the first message from the bag for a given key.
	 *
	 * @param  string  $key
	 * @param  string  $format
	 * @return string
	 */
	public function first($key = null, $format = null)
	{
		$messages = is_null($key) ? $this->all($format) : $this->get($key, $format);

		return count($messages) > 0 ? $messages[0] : '';
	}

	/**
	 * Get all of the messages from the bag for a given key.
	 *
	 * @param  string  $key
	 * @param  string  $format
	 * @return array
	 */
	public function get($key, $format = null)
	{
		// If the message exists in the container, we will transform it and return
		// the message. Otherwise, we'll return an empty array since the entire
		// methods is to return back an array of messages in the first place.
		if (array_key_exists($key, $this->messages))
		{
			return $this->transform($this->messages[$key], $this->checkFormat($format), $key);
		}

		return array();
	}

	/**
	 * Get all of the messages for every key in the bag.
	 *
	 * @param  string  $format
	 * @return array
	 */
	public function all($format = null)
	{
		$format = $this->checkFormat($format);

		$all = array();

		foreach ($this->messages as $key => $messages)
		{
			$all = array_merge($all, $this->transform($messages, $format, $key));
		}

		return $all;
	}

	/**
	 * Format an array of messages.
	 *
	 * @param  array   $messages
	 * @param  string  $format
	 * @param  string  $messageKey
	 * @return array
	 */
	protected function transform($messages, $format, $messageKey)
	{
		$messages = (array) $messages;

		// We will simply spin through the given messages and transform each one
		// replacing the :message place holder with the real message allowing
		// the messages to be easily formatted to each developer's desires.
		$replace = array(':message', ':key');

		foreach ($messages as &$message)
		{
			$message = str_replace($replace, array($message, $messageKey), $format);
		}

		return $messages;
	}

	/**
	 * Get the appropriate format based on the given format.
	 *
	 * @param  string  $format
	 * @return string
	 */
	protected function checkFormat($format)
	{
		return $format ?: $this->format;
	}

	/**
	 * Get the raw messages in the container.
	 *
	 * @return array
	 */
	public function getMessages()
	{
		return $this->messages;
	}

	/**
	 * Get the messages for the instance.
	 *
	 * @return \Illuminate\Support\MessageBag
	 */
	public function getMessageBag()
	{
		return $this;
	}

	/**
	 * Get the default message format.
	 *
	 * @return string
	 */
	public function getFormat()
	{
		return $this->format;
	}

	/**
	 * Set the default message format.
	 *
	 * @param  string  $format
	 * @return \Illuminate\Support\MessageBag
	 */
	public function setFormat($format = ':message')
	{
		$this->format = $format;

		return $this;
	}

	/**
	 * Determine if the message bag has any messages.
	 *
	 * @return bool
	 */
	public function isEmpty()
	{
		return ! $this->any();
	}

	/**
	 * Determine if the message bag has any messages.
	 *
	 * @return bool
	 */
	public function any()
	{
		return $this->count() > 0;
	}

	/**
	 * Get the number of messages in the container.
	 *
	 * @return int
	 */
	public function count()
	{
		return count($this->messages, COUNT_RECURSIVE) - count($this->messages);
	}

	/**
	 * Get the instance as an array.
	 *
	 * @return array
	 */
	public function toArray()
	{
		return $this->getMessages();
	}

	/**
	 * Convert the object into something JSON serializable.
	 *
	 * @return array
	 */
	public function jsonSerialize()
	{
		return $this->toArray();
	}

	/**
	 * Convert the object to its JSON representation.
	 *
	 * @param  int  $options
	 * @return string
	 */
	public function toJson($options = 0)
	{
		return json_encode($this->toArray(), $options);
	}

	/**
	 * Convert the message bag to its string representation.
	 *
	 * @return string
	 */
	public function __toString()
	{
		return $this->toJson();
	}

}