<?php
namespace Kant\Support;

use Countable;
use JsonSerializable;

class MessageBag implements Countable, JsonSerializable
{

    /**
     * All of the registered messages.
     *
     * @var array
     */
    protected $messages = [];

    /**
     * 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 $messages = [])
    {
        foreach ($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;
    }

    /**
     * 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]);
    }

    /**
     * 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 messages exist for all of the given keys.
     *
     * @param array|string $key            
     * @return bool
     */
    public function has($key)
    {
        if (is_null($key)) {
            return $this->any();
        }
        
        $keys = is_array($key) ? $key : func_get_args();
        
        foreach ($keys as $key) {
            if ($this->first($key) === '') {
                return false;
            }
        }
        
        return true;
    }

    /**
     * Determine if messages exist for any of the given keys.
     *
     * @param array $keys            
     * @return bool
     */
    public function hasAny($keys = [])
    {
        foreach ($keys as $key) {
            if ($this->has($key)) {
                return true;
            }
        }
        
        return false;
    }

    /**
     * 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);
        
        $firstMessage = Arr::first($messages, null, '');
        
        return is_array($firstMessage) ? Arr::first($firstMessage) : $firstMessage;
    }

    /**
     * Get all of the messages from the bag for a given key.
     *
     * @param string $key            
     * @param string $format            
     * @return array
     */
    public function get($key, $format = null)
    {
        // If the message exists in the container, we will transform it and return
        // the message. Otherwise, we'll check if the key is implicit & collect
        // all the messages that match a given key and output it as an array.
        if (array_key_exists($key, $this->messages)) {
            return $this->transform($this->messages[$key], $this->checkFormat($format), $key);
        }
        
        if (Str::contains($key, '*')) {
            return $this->getMessagesForWildcardKey($key, $format);
        }
        
        return [];
    }

    /**
     * Get the messages for a wildcard key.
     *
     * @param string $key            
     * @param string|null $format            
     * @return array
     */
    protected function getMessagesForWildcardKey($key, $format)
    {
        return collect($this->messages)->filter(function ($messages, $messageKey) use($key) {
            return Str::is($key, $messageKey);
        })
            ->map(function ($messages, $messageKey) use($format) {
            return $this->transform($messages, $this->checkFormat($format), $messageKey);
        })
            ->all();
    }

    /**
     * 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 = [];
        
        foreach ($this->messages as $key => $messages) {
            $all = array_merge($all, $this->transform($messages, $format, $key));
        }
        
        return $all;
    }

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

    /**
     * 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 = [
            ':message',
            ':key'
        ];
        
        foreach ($messages as &$message) {
            $message = str_replace($replace, [
                $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 messages()
    {
        return $this->messages;
    }

    /**
     * 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->jsonSerialize(), $options);
    }

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