#ifndef GENTOOBROWSE_SERVICE_UTILS_LEXER_H
#define GENTOOBROWSE_SERVICE_UTILS_LEXER_H

#include <vector>
#include <glibmm/ustring.h>
#include <set>
#include <boost/tuple/tuple.hpp>
#include <boost/function.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/optional.hpp>

namespace Gentoo {
	namespace Utils {
		class Lexer {
			public:
				class Pattern {
					public:
						virtual ~Pattern() = default;

						virtual bool matches(const gchar *, size_t, size_t) const = 0;
						virtual size_t matchedLength() const = 0;
						virtual boost::optional<Glib::ustring> match(int) const = 0;
				};
				typedef boost::shared_ptr<Pattern> PatternPtr;

				typedef std::string State;
				typedef std::set<State> States;

				class ExecuteState {
					public:
						ExecuteState();

						void pushState(const State &);
						void popState();
						void setState(const State &);
						const State & getState() const;

						size_t position;
						PatternPtr pattern;

					private:
						std::vector<State> stateStack;
				};

				typedef boost::function<void(ExecuteState *)> Handler;
				typedef boost::tuple<States, PatternPtr, Handler> Rule;
				typedef std::vector<Rule> Rules;

				static const State InitialState;
				Rules rules;

				static PatternPtr regex(const Glib::ustring &, GRegexCompileFlags compile = (GRegexCompileFlags)0, GRegexMatchFlags match = (GRegexMatchFlags)0);

			public:
				void extract(const gchar * string, size_t length) const;
		};

	}
}

#endif