#include "../../main.h"
#include <boost/logic/tribool.hpp>
#include <boost/tuple/tuple.hpp>

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

		/// 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++);
				if (result || !result)
					return boost::make_tuple(result, begin);
			}
			boost::tribool result = boost::indeterminate;
			return boost::make_tuple(result, begin);
		}

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

		/// 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,
			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
		}state_;
};