//
// request_parser.h
// ~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#pragma once
#ifndef HTTP_REQUEST_PARSER_H
#define HTTP_REQUEST_PARSER_H

#include <boost/logic/tribool.hpp>
#include <boost/tuple/tuple.hpp>

namespace http {
namespace server {

class request;

/// Parser for incoming requests.
class request_parser
{
public:
  /// Construct ready to parse the request method.
  request_parser() = default;

  /// Reset to initial parser state.
  void reset();

  /// Parse some data. The tribool return value is true when a complete request
  /// has been parsed, false if the data is invalid, indeterminate when more
  /// data is required. The InputIterator return value indicates how much of the
  /// input has been consumed.
  template <typename InputIterator>
  boost::tuple<boost::tribool, InputIterator> parse(request& req,
      InputIterator& begin, InputIterator end)
  {
	  while ( begin != end)
	  {
		  boost::tribool result = consume(req, begin, end);
			
		  if (result || !result) {
			  return { result, begin };
		  }
	  }
	  boost::tribool result = boost::indeterminate;
	  return { result, begin };
  }


private:
  /// Handle the next character of input.
  boost::tribool consume(request& req, const char* &input, const char *end);

  /// Check if a byte is an HTTP character.
  static bool is_char(int c);

  /// Check if a byte is an HTTP control character.
  static bool is_ctl(int c);

  /// Check if a byte is defined as an HTTP tspecial character.
  static bool is_tspecial(int c);

  /// Check if a byte is a digit.
  static bool is_digit(int c);

  /// The current state of the parser.
  enum state
  {
	  method_start,
	  method,
	  uri_start,
	  uri,
	  http_version_h,
	  http_version_t_1,
	  http_version_t_2,
	  http_version_p,
	  http_version_slash,
	  http_version_major_start,
	  http_version_major,
	  http_version_minor_start,
	  http_version_minor,
	  expecting_newline_1,
	  header_line_start,
	  header_lws,
	  header_name,
	  space_before_header_value,
	  header_value,
	  expecting_newline_2,
	  expecting_newline_3,
	  reading_content
  } state_{ method_start };
};

} // namespace server
} // namespace http

#endif // HTTP_REQUEST_PARSER_H
