/*
 * \brief  Handling command-line for Noux processes
 * \author Norman Feske
 * \date   2011-01-17
 */

/*
 * Copyright (C) 2011-2017 Genode Labs GmbH
 *
 * This file is part of the Genode OS framework, which is distributed
 * under the terms of the GNU Affero General Public License version 3.
 */

#ifndef _NOUX__ARGS_H_
#define _NOUX__ARGS_H_

/* Genode includes */
#include <base/attached_ram_dataspace.h>
#include <util/string.h>
#include <base/log.h>

namespace Noux {
	class Args;
	class Args_dataspace;
}


class Noux::Args
{
	protected:

		char * const _buf;
		size_t const _buf_size;
		size_t       _len;

		size_t _free_size() const
		{
			/*
			 * Keep space for two trailing zeros, indicating the end of the
			 * stream of strings.
			 */
			return _buf_size - _len - 2;
		}

	public:

		class Overrun { };

		/**
		 * Constructor
		 *
		 * \param buf       argument buffer
		 * \param buf_size  size of argument buffer in character,
		 *                  must be at least 2
		 */
		Args(char *buf, size_t buf_size)
		: _buf(buf), _buf_size(buf_size), _len(0)
		{
			if (buf_size <= 2)
				throw Overrun();

			/* search end of string stream (two subsequent zeros) */
			for (; (_buf[_len] || _buf[_len + 1]) && (_len < _buf_size - 2); _len++);

			/* ensure termination of argument buffer */
			_buf[_buf_size - 1] = 0;
			_buf[_buf_size - 2] = 0;
		}

		Args() : _buf(0), _buf_size(0), _len(0) { }

		bool valid() const { return _buf_size > 0; }

		size_t len() const { return _len; }

		char const *base() const { return _buf; }

		void append(char const *arg)
		{
			size_t const arg_len = strlen(arg);

			if (arg_len > _free_size())
				throw Overrun();

			strncpy(_buf + _len, arg, _buf_size - _len);

			_len += arg_len + 1; /* keep null termination between strings */

			/* mark end of stream of strings */
			_buf[_len] = 0;
		}

		void dump()
		{
			for (unsigned i = 0, j = 0; _buf[i] && (i < _buf_size - 2);
			     i += strlen(&_buf[i]) + 1, j++)
				log("arg(", j, "): \"", Cstring(&_buf[i]), "\"");
		}
};


struct Noux::Args_dataspace : private Attached_ram_dataspace, Args
{
	Args_dataspace(Ram_allocator &ram, Region_map &rm,
	               size_t size, Args const &from = Args())
	:
		Attached_ram_dataspace(ram, rm, size),
		Args(local_addr<char>(), size)
	{
		if (from.len() > size - 2)
			throw Overrun();

		memcpy(_buf, from.base(), from.len() + 1);
	}

	using Attached_ram_dataspace::cap;
};

#endif /* _NOUX__ARGS_H_ */