<?php defined('SYSPATH') or die('No direct script access.');

/**

 * Kohana_Http_Header_Value represents a value assigned to an HTTP header, i.e.

 *

 *      Accept: [key=]value[; property[=property_value][; ...]]

 *

 * Values are either single values,

 *

 * @package    Kohana

 * @category   Http

 * @author     Kohana Team

 * @since      3.1.0

 * @copyright  (c) 2008-2011 Kohana Team

 * @license    http://kohanaphp.com/license

 */

class Kohana_Http_Header_Value {



	/**

	 * @var     float    The default quality header property value

	 */

	public static $default_quality = 1.0;



	/**

	 * Detects and returns key/value pairs

	 *

	 * @param   string   $string String to parse

	 * @param   string   $separator

	 * @return  array

	 */

	public static function parse_key_value($string, $separator = '=')

	{

		$parts = explode($separator, trim($string), 2);



		if (count($parts) == 1)

		{

			return $parts;

		}

		else

		{

			return array($parts[0] => $parts[1]);

		}

	}



	/**

	 * @var     array

	 */

	public $properties = array();



	/**

	 * @var     void|string

	 */

	public $key;



	/**

	 * @var     array

	 */

	public $value = array();



	/**

	 * Builds the header field

	 *

	 * @param   mixed    value  configuration array passed

	 * @param   boolean  no_parse  skip parsing of the string (i.e. user-agent)

	 * @throws  Kohana_Http_Exception

	 */

	public function __construct($value, $no_parse = FALSE)

	{

		// If no parse is set, set the value and get out of here (user-agent)

		if ($no_parse)

		{

			$this->key = NULL;

			$this->value = $value;

			return;

		}



		// If configuration array passed

		if (is_array($value))

		{

			// Parse each value

			foreach ($value as $k => $v)

			{

				// If the key is a property

				if (property_exists($this, $k))

				{

					// Map values

					$this->$k = $v;

				}

			}



		}

		// If value is a string

		elseif (is_string($value))

		{

			// Detect properties

			if (strpos($value, ';') !== FALSE)

			{

				// Remove properties from the string

				$parts = explode(';', $value);

				$value = array_shift($parts);



				// Parse the properties

				$properties = array();



				// Foreach part

				foreach ($parts as $part)

				{

					// Merge the parsed values

					$properties = array_merge(Http_Header_Value::parse_key_value($part), $properties);

				}



				// Apply the parsed values

				$this->properties = $properties;

			}



			// Parse the value and get key

			$value = Http_Header_Value::parse_key_value($value);

			$key = key($value);



			// If the key is a string

			if (is_string($key))

			{

				// Apply the key as a property

				$this->key = $key;

			}



			// Apply the value

			$this->value = current($value);

		}

		// Unrecognised value type

		else

		{

			throw new Http_Exception(__METHOD__.' unknown header value type: :type. array or string allowed.', array(':type' => gettype($value)));

		}

	}



	/**

	 * Provides direct access to the key of this header value

	 *

	 * @param   string   $key  Key value to set

	 * @return  mixed

	 */

	public function key($key = NULL)

	{

		if ($key === NULL)

		{

			return $this->key;

		}

		else

		{

			$this->key = $key;

			return $this;

		}

	}



	/**

	 * Provides direct access to the value of this header value

	 *

	 * @param   string   $value Value to set

	 * @return  mixed

	 */

	public function value($value = NULL)

	{

		if ($value === NULL)

		{

			return $this->value;

		}

		else

		{

			$this->value = $value;

			return $this;

		}

	}



	/**

	 * Provides direct access to the properties of this header value

	 *

	 * @param   array    $properties Properties to set to this value

	 * @return  mixed

	 */

	public function properties(array $properties = array())

	{

		if ( ! $properties)

		{

			return $this->properties;

		}

		else

		{

			$this->properties = $properties;

			return $this;

		}

	}



	/**

	 * Magic method to handle object being cast to

	 * string. Produces the following header value syntax

	 *

	 *      [key=]value[; property[=property_value][; ... ]]

	 *

	 * @return  string

	 */

	public function __toString()

	{



		$string = ($this->key !== NULL) ? ($this->key.'='.$this->value) : $this->value;



		if ($this->properties)

		{

			$props = array($string);

			foreach ($this->properties as $k => $v)

			{

				$props[] = is_int($k) ? $v : ($k.'='.$v);

			}

			$string = implode('; ', $props);

		}



		return $string;

	}



} // End Http_Header_Field