<?php

/**

 * SimplePie

 *

 * A PHP-Based RSS and Atom Feed Framework.

 * Takes the hard work out of managing a complete RSS/Atom solution.

 *

 * Copyright (c) 2004-2016, Ryan Parman, Sam Sneddon, Ryan McCue, and contributors

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without modification, are

 * permitted provided that the following conditions are met:

 *

 * 	* Redistributions of source code must retain the above copyright notice, this list of

 * 	  conditions and the following disclaimer.

 *

 * 	* Redistributions in binary form must reproduce the above copyright notice, this list

 * 	  of conditions and the following disclaimer in the documentation and/or other materials

 * 	  provided with the distribution.

 *

 * 	* Neither the name of the SimplePie Team nor the names of its contributors may be used

 * 	  to endorse or promote products derived from this software without specific prior

 * 	  written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS

 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY

 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS

 * AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR

 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 *

 * @package SimplePie

 * @copyright 2004-2016 Ryan Parman, Sam Sneddon, Ryan McCue

 * @author Ryan Parman

 * @author Sam Sneddon

 * @author Ryan McCue

 * @link http://simplepie.org/ SimplePie

 * @license http://www.opensource.org/licenses/bsd-license.php BSD License

 */

/**

 * HTTP Response Parser

 *

 * @package SimplePie

 * @subpackage HTTP

 */

class SimplePie_HTTP_Parser

{

	/**

	 * HTTP Version

	 *

	 * @var float

	 */

	public $http_version = 0.0;

	/**

	 * Status code

	 *

	 * @var int

	 */

	public $status_code = 0;

	/**

	 * Reason phrase

	 *

	 * @var string

	 */

	public $reason = '';

	/**

	 * Key/value pairs of the headers

	 *

	 * @var array

	 */

	public $headers = array();

	/**

	 * Body of the response

	 *

	 * @var string

	 */

	public $body = '';

	/**

	 * Current state of the state machine

	 *

	 * @var string

	 */

	protected $state = 'http_version';

	/**

	 * Input data

	 *

	 * @var string

	 */

	protected $data = '';

	/**

	 * Input data length (to avoid calling strlen() everytime this is needed)

	 *

	 * @var int

	 */

	protected $data_length = 0;

	/**

	 * Current position of the pointer

	 *

	 * @var int

	 */

	protected $position = 0;

	/**

	 * Name of the hedaer currently being parsed

	 *

	 * @var string

	 */

	protected $name = '';

	/**

	 * Value of the hedaer currently being parsed

	 *

	 * @var string

	 */

	protected $value = '';

	/**

	 * Create an instance of the class with the input data

	 *

	 * @param string $data Input data

	 */

	public function __construct($data)

	{

		$this->data = $data;

		$this->data_length = strlen($this->data);

	}

	/**

	 * Parse the input data

	 *

	 * @return bool true on success, false on failure

	 */

	public function parse()

	{

		while ($this->state && $this->state !== 'emit' && $this->has_data())

		{

			$state = $this->state;

			$this->$state();

		}

		$this->data = '';

		if ($this->state === 'emit' || $this->state === 'body')

		{

			return true;

		}

		$this->http_version = '';

		$this->status_code = '';

		$this->reason = '';

		$this->headers = array();

		$this->body = '';

		return false;

	}

	/**

	 * Check whether there is data beyond the pointer

	 *

	 * @return bool true if there is further data, false if not

	 */

	protected function has_data()

	{

		return (bool) ($this->position < $this->data_length);

	}

	/**

	 * See if the next character is LWS

	 *

	 * @return bool true if the next character is LWS, false if not

	 */

	protected function is_linear_whitespace()

	{

		return (bool) ($this->data[$this->position] === "\x09"

			|| $this->data[$this->position] === "\x20"

			|| ($this->data[$this->position] === "\x0A"

				&& isset($this->data[$this->position + 1])

				&& ($this->data[$this->position + 1] === "\x09" || $this->data[$this->position + 1] === "\x20")));

	}

	/**

	 * Parse the HTTP version

	 */

	protected function http_version()

	{

		if (strpos($this->data, "\x0A") !== false && strtoupper(substr($this->data, 0, 5)) === 'HTTP/')

		{

			$len = strspn($this->data, '0123456789.', 5);

			$this->http_version = substr($this->data, 5, $len);

			$this->position += 5 + $len;

			if (substr_count($this->http_version, '.') <= 1)

			{

				$this->http_version = (float) $this->http_version;

				$this->position += strspn($this->data, "\x09\x20", $this->position);

				$this->state = 'status';

			}

			else

			{

				$this->state = false;

			}

		}

		else

		{

			$this->state = false;

		}

	}

	/**

	 * Parse the status code

	 */

	protected function status()

	{

		if ($len = strspn($this->data, '0123456789', $this->position))

		{

			$this->status_code = (int) substr($this->data, $this->position, $len);

			$this->position += $len;

			$this->state = 'reason';

		}

		else

		{

			$this->state = false;

		}

	}

	/**

	 * Parse the reason phrase

	 */

	protected function reason()

	{

		$len = strcspn($this->data, "\x0A", $this->position);

		$this->reason = trim(substr($this->data, $this->position, $len), "\x09\x0D\x20");

		$this->position += $len + 1;

		$this->state = 'new_line';

	}

	/**

	 * Deal with a new line, shifting data around as needed

	 */

	protected function new_line()

	{

		$this->value = trim($this->value, "\x0D\x20");

		if ($this->name !== '' && $this->value !== '')

		{

			$this->name = strtolower($this->name);

			// We should only use the last Content-Type header. c.f. issue #1

			if (isset($this->headers[$this->name]) && $this->name !== 'content-type')

			{

				$this->headers[$this->name] .= ', ' . $this->value;

			}

			else

			{

				$this->headers[$this->name] = $this->value;

			}

		}

		$this->name = '';

		$this->value = '';

		if (substr($this->data[$this->position], 0, 2) === "\x0D\x0A")

		{

			$this->position += 2;

			$this->state = 'body';

		}

		elseif ($this->data[$this->position] === "\x0A")

		{

			$this->position++;

			$this->state = 'body';

		}

		else

		{

			$this->state = 'name';

		}

	}

	/**

	 * Parse a header name

	 */

	protected function name()

	{

		$len = strcspn($this->data, "\x0A:", $this->position);

		if (isset($this->data[$this->position + $len]))

		{

			if ($this->data[$this->position + $len] === "\x0A")

			{

				$this->position += $len;

				$this->state = 'new_line';

			}

			else

			{

				$this->name = substr($this->data, $this->position, $len);

				$this->position += $len + 1;

				$this->state = 'value';

			}

		}

		else

		{

			$this->state = false;

		}

	}

	/**

	 * Parse LWS, replacing consecutive LWS characters with a single space

	 */

	protected function linear_whitespace()

	{

		do

		{

			if (substr($this->data, $this->position, 2) === "\x0D\x0A")

			{

				$this->position += 2;

			}

			elseif ($this->data[$this->position] === "\x0A")

			{

				$this->position++;

			}

			$this->position += strspn($this->data, "\x09\x20", $this->position);

		} while ($this->has_data() && $this->is_linear_whitespace());

		$this->value .= "\x20";

	}

	/**

	 * See what state to move to while within non-quoted header values

	 */

	protected function value()

	{

		if ($this->is_linear_whitespace())

		{

			$this->linear_whitespace();

		}

		else

		{

			switch ($this->data[$this->position])

			{

				case '"':

					// Workaround for ETags: we have to include the quotes as

					// part of the tag.

					if (strtolower($this->name) === 'etag')

					{

						$this->value .= '"';

						$this->position++;

						$this->state = 'value_char';

						break;

					}

					$this->position++;

					$this->state = 'quote';

					break;

				case "\x0A":

					$this->position++;

					$this->state = 'new_line';

					break;

				default:

					$this->state = 'value_char';

					break;

			}

		}

	}

	/**

	 * Parse a header value while outside quotes

	 */

	protected function value_char()

	{

		$len = strcspn($this->data, "\x09\x20\x0A\"", $this->position);

		$this->value .= substr($this->data, $this->position, $len);

		$this->position += $len;

		$this->state = 'value';

	}

	/**

	 * See what state to move to while within quoted header values

	 */

	protected function quote()

	{

		if ($this->is_linear_whitespace())

		{

			$this->linear_whitespace();

		}

		else

		{

			switch ($this->data[$this->position])

			{

				case '"':

					$this->position++;

					$this->state = 'value';

					break;

				case "\x0A":

					$this->position++;

					$this->state = 'new_line';

					break;

				case '\\':

					$this->position++;

					$this->state = 'quote_escaped';

					break;

				default:

					$this->state = 'quote_char';

					break;

			}

		}

	}

	/**

	 * Parse a header value while within quotes

	 */

	protected function quote_char()

	{

		$len = strcspn($this->data, "\x09\x20\x0A\"\\", $this->position);

		$this->value .= substr($this->data, $this->position, $len);

		$this->position += $len;

		$this->state = 'value';

	}

	/**

	 * Parse an escaped character within quotes

	 */

	protected function quote_escaped()

	{

		$this->value .= $this->data[$this->position];

		$this->position++;

		$this->state = 'quote';