<?php
/**
 * Sleepy - a REST framework
 *
 *
 * A PHP Rest Framework valuing convention over configuration,
 * but aiming to be as flexible as possible
 *
 * @author Timothy J. Warren
 */

namespace Sleepy\Core;

/**
 * Class for accessing request data
 *
 * @method array server()
 * @method array env()
 * @method array get()
 * @method array post()
 * @method array put()
 * @method array delete()
 * @method array cookie()
 */
class Input {

	// --------------------------------------------------------------------------
	// ! Stuff PHP Forgot
	// --------------------------------------------------------------------------

	/**
	 * The HTTP verb for the current request
	 *
	 * @var string
	 */
	protected $verb = 'get';

	/**
	 * Class member for put data
	 *
	 * @var array
	 */
	protected $put = [];

	/**
	 * Class member for delete data
	 *
	 * @var array
	 */
	protected $delete = [];

	/**
	 * Class member for options data
	 *
	 * @var array
	 */
	protected $options = [];

	// --------------------------------------------------------------------------
	// ! Working around PHP for nicer usability
	// --------------------------------------------------------------------------

	/**
	 * An array mapping the function to the appropriate superglobal
	 *
	 * @var array
	 */
	protected $var_map = [];

	/**
	 * The request's HTTP headers from the $_SERVER superglobal
	 *
	 * @var array
	 */
	protected $request_headers = [];

	/**
	 * The request headers parsed into a more useful array
	 *
	 * @var array
	 */
	protected $parsed_headers = [];

	// --------------------------------------------------------------------------
	// ! Methods
	// --------------------------------------------------------------------------

	/**
	 * Instantiates the class
	 */
	public function __construct()
	{
		// Type of HTTP request
		$this->verb = \strtolower($_SERVER['REQUEST_METHOD']);

		// Parse put and delete requests into input variables
		// @codeCoverageIgnoreStart
		if (isset($this->{$this->verb}))
		{
			$raw = \file_get_contents('php://input');
			\parse_str($raw, $this->{$this->verb});
		}
		
		// Set mapping for superglobals, since
		// variable variables don't seem to work
		// with superglobals :/
		$this->var_map = [
			'get' => $_GET,
			'post' => $_POST,
			'server' => $_SERVER,
			'env' => $_ENV,
			'cookie' => $_COOKIE
		];
		// @codeCoverageIgnoreEnd

		// Parse request headers from $_SERVER
		foreach($_SERVER as $key => $val)
		{
			if (strpos($key, 'HTTP_') === 0)
			{
				$new_key = \strtolower(\strtr($key, [
					'HTTP_' => '',
					'_' => '-'
				]));
				$this->request_headers[$new_key] = $val;
			}
		}
	}

	/**
	 * Wrapper method for input arrays
	 *
	 * Actually works as get,post,put,delete,cookie,server,and env functions
	 * all wrapped up in one - because boilerplate is bad!
	 *
	 * @param string $name - name of input array
	 * @param array $args - function arguments
	 * @return mixed
	 * @throws \DomainException
	 */
	public function __call($name, $args=[])
	{
		// Predefine arguments for input array getters
		if ( ! isset($args[0])) $args[0] = NULL;
		if ( ! isset($args[1])) $args[1] = FILTER_SANITIZE_STRING;
		$index = $args[0];
		$filter = $args[1];

		if (isset($this->var_map[$name]) || isset($this->$name))
		{
			// Get an input variable value
			return $this->get_var($name, $index, $filter);
		}

		// What kind of request are you trying to make?!
		throw new \DomainException('Invalid input array.');
	}

	/**
	 * Return header(s) sent from the request
	 *
	 * @param string $index
	 * @return mixed
	 */
	public function header($index = NULL)
	{
		if ($index !== NULL)
		{
			$index = (\strtolower(\str_replace([' ', '_'], '-', $index)));

			if (isset($this->request_headers[$index]))
			{
				return $this->request_headers[$index];
			}

			return NULL;
		}

		return $this->request_headers;
	}

	/**
	 * Return parsed header(s) sent from the request
	 *
	 * @param string $index
	 * @return mixed
	 */
	public function header_array($index = NULL)
	{
		if (empty($this->parsed_headers))
		{
			$this->parsed_headers = $this->parse_headers();
		}

		if ($index !== NULL)
		{
			$index = (str_replace([' ', '-'], '_', $index));

			if (isset($this->parsed_headers[$index]))
			{
				return $this->parsed_headers[$index];
			}

			return NULL;
		}

		return $this->parsed_headers;
	}

	/**
	 * Convert headers to a parsed array of values
	 *
	 * @return array
	 */
	protected function parse_headers()
	{
		foreach($this->request_headers as $header => $value)
		{
			$has_semi = strpos($value, ';') !== FALSE;
			$has_comma = strpos($value, ',') !== FALSE;
			$has_eq = strpos($value, '=') !== FALSE;

			// Parse the user agent separately
			if ($header === 'user-agent')
			{
				$this->parsed_headers[$header] = $this->parse_user_agent($value);
				continue;
			}
			// Parse accept-type headers separately as well
			else if (strpos($header, 'accept') === 0)
			{
				$this->parsed_headers[$header] = $this->parse_accept_header($value);
			}
			// If the header has a comma, and not a semicolon, split on the comma
			else if ( ! $has_semi && $has_comma)
			{
				$this->parsed_headers[$header] = explode(",", $value);
				continue;
			}
			// Parse cookies and other headers with values like query strings
			else if ($has_eq && ! $has_semi)
			{
				parse_str($value, $this->parsed_headers[$header]);
				continue;
			}
			// Anything else, just leave it as a string
			else
			{
				$this->parsed_headers[$header] = $value;
				continue;
			}
		}

		return $this->parsed_headers;
	}

	/**
	 * Parse a browser useragent into a set of useful key-value pairs
	 *
	 * @param string $ua_string
	 * @return array
	 */
	protected function parse_user_agent($ua_string)
	{
		$user_agent = [];

		$slash_matches = [];
		$slash_pattern = "`[A-Z]+/[0-9]+((\.[0-9]+)+)?`i";

		$paren_matches = [];
		$paren_pattern = "`\(.*?\)`i";

		// Get all the foo/12.3 paterns from the user agent string
		preg_match_all($slash_pattern, $ua_string, $slash_matches);
		foreach($slash_matches[0] as $arr)
		{
			list($key, $version) = explode("/", $arr);
			$user_agent['versions'][$key] = $version;
		}

		// Get all the info from parenthasized items
		preg_match_all($paren_pattern, $ua_string, $paren_matches);
		foreach($paren_matches[0] as $arr)
		{
			$arr = str_replace(['(',')'], '', $arr);
			if (strpos($arr, ';') !== FALSE)
			{
				$user_agent['os'] = explode('; ', $arr);
			}
			else
			{
				$user_agent['misc'] = $arr;
			}
		}

		return $user_agent;
	}

	/**
	 * Parse an accept-type header into an ordered list
	 * of values
	 *
	 * @param string $value
	 * @return array
	 */
	protected function parse_accept_header($value)
	{
		$q_types = [];
		// A fake value so I can shift it off to have a 1-indexed array
		$high_types = [];
		$count = 1;

		// Split into segments of different values
		$groups = explode(',', $value);

		foreach($groups as $group)
		{
			$group = \trim($group);
			$pair = explode(';q=', $group);

			if (count($pair) === 2)
			{
				list($val, $q) = $pair;
				$q_types[$q] = $val;
			}
			else
			{
				$high_types[$count] = current($pair);
				$count++;
			}
		}

		// Add an additional fake value so we can
		// have a 1-indexed array
		$high_types[$count] = 'foo';
		$high_types = array_reverse($high_types);
		unset($high_types[0]);

		$output = $q_types;

		// Merge the arrays manually to maintain
		// keys, and thus ordering
		foreach($high_types as $k => $v)
		{
			$output[$k] = $v;
		}

		krsort($output, SORT_NUMERIC);

		return $output;
	}
	
	/**
	 * Get superglobal or generated input array value
	 * @param string $type - HTTP verb
	 * @param string $index - variable in the input array
	 * @param int $filter - PHP filter_var flag
	 * @return mixed
	 */
	protected function get_var($type, $index=NULL, $filter=\FILTER_SANITIZE_STRING)
	{
		// Determine if superglobal or generated
		$var = array_key_exists($type, $this->var_map)
			? $this->var_map[$type]
			: $this->$type;
		
		// Return the whole array if the index is null
		if ($index === NULL)
		{
			return ($filter !== NULL) ? \filter_var_array($var, $filter) : $var;
		}
		
		// Prevent errors for non-existant variables
		if ( ! isset($var[$index]))
		{
			return NULL;
		}
		
		return ($filter !== NULL) ? \filter_var($var[$index], $filter) : $var[$index];
	}

}
// End of core/Input.php