/* Copyright (C) 2020 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
	A basic_string derivative that works with uint16_t as its underlying char
	type.
*/
#ifndef INCLUDED_UTF16STRING
#define INCLUDED_UTF16STRING

// On Linux, wchar_t is 32-bit, so define a new version of it.
// We now use this code on Windows as well, because wchar_t is a
// native type and distinct from utf16_t.
#include <algorithm>
#include <cstring>
#include <memory>
#include <string>


typedef uint16_t utf16_t;

// jw: this was originally defined in the std namespace, which is at
// least frowned upon if not illegal. giving it a new name and passing it
// as a template parameter is the "correct" and safe way.

struct utf16_traits
{
	typedef utf16_t		char_type;
	typedef int			int_type;
	typedef std::streampos	pos_type;
	typedef std::streamoff	off_type;
	typedef std::mbstate_t	state_type;

	static void assign(char_type& c1, const char_type& c2)
	{ c1 = c2; }

	static bool eq(const char_type& c1, const char_type& c2)
	{ return c1 == c2; }

	static bool lt(const char_type& c1, const char_type& c2)
	{ return c1 < c2; }

	static int compare(const char_type* s1, const char_type* s2, size_t n)
	{
		return memcmp(s1, s2, n*sizeof(char_type));
	}

	static size_t length(const char_type* s)
	{
		const char_type* end=s;
		while (*end) end++;
		return (size_t)(end-s);
	}

	static const char_type* find(const char_type* s, size_t n, const char_type& a)
	{
		const char_type *end = s+n;
		const char_type *res = std::find(s, end, a);
		return (res != end)?res:NULL;
	}

	static char_type* move(char_type* s1, const char_type* s2, size_t n)
	{
		return (char_type *)memmove(s1, s2, n*sizeof(char_type));
	}

	static char_type* copy(char_type* s1, const char_type* s2, size_t n)
	{
		return (char_type *)memcpy(s1, s2, n*sizeof(char_type));
	}

	static char_type* assign(char_type* s, size_t n, char_type a)
	{
		while (n--)
		{
			s[n]=a;
		}
		return s;
	}

	static char_type to_char_type(const int_type& c)
	{ return (char_type)c; }

	static int_type to_int_type(const char_type& c)
	{ return (int_type)c; }

	static bool eq_int_type(const int_type& c1, const int_type& c2)
	{ return c1 == c2; }

	static int_type eof()
	{ return -1; }

	static int_type not_eof(const int_type& c)
	{ return (c == -1) ? 0 : c; }
};

typedef std::basic_string<utf16_t, utf16_traits> utf16string;
typedef std::basic_stringstream<utf16_t, utf16_traits> utf16stringstream;

#endif