/*
 * This file is a part of PikoTools
 * and is distributed under the 2-Clause BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/*
 * Copyright (c) 2017-2022, Tomasz Sowa
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef headerfile_pikotools_src_convert_strtoint
#define headerfile_pikotools_src_convert_strtoint

#include <limits>
#include "text.h"
#include "misc.h"


namespace pt
{


template<typename CharType>
unsigned long long to_ull(const CharType * str, int base = 10, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	unsigned long long res = 0;
	bool carry = false;
	int digit;

	SetOverflow(was_overflow, false);

	if( allow_skip_whitechars )
		str = skip_white(str);

	while( !carry && is_digit(*str, base, &digit) )
	{
	#ifdef __GNUC__
		carry = __builtin_mul_overflow(res, static_cast<unsigned long long>(base), &res);

		if( !carry )
		{
			carry = __builtin_add_overflow(res, static_cast<unsigned long long>(digit), &res);
		}
	#else
		// on other compilers than GCC or CLANG we do not test overflow at the moment
		res = res * static_cast<unsigned long long>(base) + static_cast<unsigned long long>(digit);
	#endif

		str += 1;
	}

	if( carry )
	{
		if( after_str )
		{
			while( is_digit(*str, base, &digit) )
			{
				str += 1;
			}
		}

		SetOverflow(was_overflow, true);
		res = 0;
	}

	if( after_str )
		*after_str = str;

	return res;
}


template<class StringType>
unsigned long long to_ull(const StringType & str, int base = 10, const typename StringType::value_type ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_ull(str.c_str(), base, after_str, was_overflow, allow_skip_whitechars);
}



template<typename CharType>
long long to_ll(const CharType * str, int base = 10, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	bool was_sign = false;
	bool was_overflow_u = false;

	SetOverflow(was_overflow, false);

	if( allow_skip_whitechars )
		str = skip_white(str);

	if( *str == '-' )
	{
		was_sign = true;
		str += 1;
	}

	unsigned long long uval = to_ull(str, base, after_str, &was_overflow_u, false);
	unsigned long long sign_add = ( was_sign ) ? 1 : 0;

	if( was_overflow_u )
	{
		SetOverflow(was_overflow, true);
		return 0;
	}

	if( uval > static_cast<unsigned long long>(std::numeric_limits<long long>::max()) + sign_add )
	{
		SetOverflow(was_overflow, true);
		return 0;
	}

	if( was_sign )
	{
		return static_cast<long long>(0) - static_cast<long long>(uval);
	}

	return static_cast<long long>(uval);
}



template<class StringType>
long long to_ll(const StringType & str, int base = 10, const typename StringType::value_type ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_ll(str.c_str(), base, after_str, was_overflow, allow_skip_whitechars);
}



template<typename CharType, typename IntegerType>
IntegerType to_unsigned_integer_type(const CharType * str, int base = 10, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	bool was_overflow_ll = false;

	SetOverflow(was_overflow, false);
	unsigned long long val = to_ull(str, base, after_str, &was_overflow_ll, allow_skip_whitechars);

	if( was_overflow_ll || val > static_cast<unsigned long long>(std::numeric_limits<IntegerType>::max()) )
	{
		SetOverflow(was_overflow, true);
		return 0;
	}

	return static_cast<IntegerType>(val);
}


template<class CharType>
unsigned long to_ul(const CharType * str, int base = 10, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_unsigned_integer_type<CharType, unsigned long>(str, base, after_str, was_overflow, allow_skip_whitechars);
}

template<class StringType>
unsigned long to_ul(const StringType & str, int base = 10, const typename StringType::value_type ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_unsigned_integer_type<typename StringType::value_type, unsigned long>(str.c_str(), base, after_str, was_overflow, allow_skip_whitechars);
}

template<class CharType>
unsigned int to_ui(const CharType * str, int base = 10, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_unsigned_integer_type<CharType, unsigned int>(str, base, after_str, was_overflow, allow_skip_whitechars);
}

template<class StringType>
unsigned int to_ui(const StringType & str, int base = 10, const typename StringType::value_type ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_unsigned_integer_type<typename StringType::value_type, unsigned int>(str.c_str(), base, after_str, was_overflow, allow_skip_whitechars);
}




template<typename CharType, typename IntegerType>
IntegerType to_integer_type(const CharType * str, int base = 10, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	bool was_overflow_ll = false;

	SetOverflow(was_overflow, false);
	long long val = to_ll(str, base, after_str, &was_overflow_ll, allow_skip_whitechars);

	if( was_overflow_ll ||
		val < static_cast<long long>(std::numeric_limits<IntegerType>::min()) ||
		val > static_cast<long long>(std::numeric_limits<IntegerType>::max()) )
	{
		SetOverflow(was_overflow, true);
		return 0;
	}

	return static_cast<IntegerType>(val);
}



template<class CharType>
long to_l(const CharType * str, int base = 10, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_integer_type<CharType, long>(str, base, after_str, was_overflow, allow_skip_whitechars);
}

template<class StringType>
long to_l(const StringType & str, int base = 10, const typename StringType::value_type ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_integer_type<typename StringType::value_type, long>(str.c_str(), base, after_str, was_overflow, allow_skip_whitechars);
}

template<class CharType>
int to_i(const CharType * str, int base = 10, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_integer_type<CharType, int>(str, base, after_str, was_overflow, allow_skip_whitechars);
}

template<class StringType>
int to_i(const StringType & str, int base = 10, const typename StringType::value_type ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_integer_type<typename StringType::value_type, int>(str.c_str(), base, after_str, was_overflow, allow_skip_whitechars);
}


/*
 *
 * the base will be automatically detected
 *
 * (first digit is [1-9]) - base 10
 * 0 - 8
 * # - 16
 * & - 2
 *
 */
template<typename CharType>
unsigned long long to_ull_b(const CharType * str, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	if( allow_skip_whitechars )
		str = skip_white(str);

	int base = 10;

	if( *str == '0' )
	{
		base = 8;
		str += 1;
	}
	else
	if( *str == '#' )
	{
		base = 16;
		str += 1;
	}
	else
	if( *str == '&' )
	{
		base = 2;
		str += 1;
	}

	return to_ull(str, base, after_str, was_overflow, false);
}



template<typename CharType>
long long to_ll_b(const CharType * str, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	bool was_sign = false;
	bool was_overflow_u = false;

	SetOverflow(was_overflow, false);

	if( allow_skip_whitechars )
		str = skip_white(str);

	if( *str == '-' )
	{
		was_sign = true;
		str += 1;
	}

	unsigned long long uval = to_ull_b(str, after_str, &was_overflow_u, false);
	unsigned long long sign_add = ( was_sign ) ? 1 : 0;

	if( was_overflow_u )
	{
		SetOverflow(was_overflow, true);
		return 0;
	}

	if( uval > static_cast<unsigned long long>(std::numeric_limits<long long>::max()) + sign_add )
	{
		SetOverflow(was_overflow, true);
		return 0;
	}

	if( was_sign )
	{
		return static_cast<long long>(0) - static_cast<long long>(uval);
	}

	return static_cast<long long>(uval);
}








template<typename CharType, typename IntegerType>
IntegerType to_unsigned_integer_type_b(const CharType * str, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	bool was_overflow_ll = false;

	SetOverflow(was_overflow, false);
	unsigned long long val = to_ull_b(str, after_str, &was_overflow_ll, allow_skip_whitechars);

	if( was_overflow_ll || val > static_cast<unsigned long long>(std::numeric_limits<IntegerType>::max()) )
	{
		SetOverflow(was_overflow, true);
		return 0;
	}

	return static_cast<IntegerType>(val);
}


template<class CharType>
unsigned long to_ul_b(const CharType * str, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_unsigned_integer_type_b<CharType, unsigned long>(str, after_str, was_overflow, allow_skip_whitechars);
}

template<class CharType>
unsigned int to_ui_b(const CharType * str, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_unsigned_integer_type_b<CharType, unsigned int>(str, after_str, was_overflow, allow_skip_whitechars);
}





template<typename CharType, typename IntegerType>
IntegerType to_integer_type_b(const CharType * str, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	bool was_overflow_ll = false;

	SetOverflow(was_overflow, false);
	long long val = to_ll_b(str, after_str, &was_overflow_ll, allow_skip_whitechars);

	if( was_overflow_ll ||
		val < static_cast<long long>(std::numeric_limits<IntegerType>::min()) ||
		val > static_cast<long long>(std::numeric_limits<IntegerType>::max()) )
	{
		SetOverflow(was_overflow, true);
		return 0;
	}

	return static_cast<IntegerType>(val);
}



template<class CharType>
long to_l_b(const CharType * str, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_integer_type_b<CharType, long>(str, after_str, was_overflow, allow_skip_whitechars);
}

template<class CharType>
int to_i_b(const CharType * str, const CharType ** after_str = 0, bool * was_overflow = 0, bool allow_skip_whitechars = true)
{
	return to_integer_type_b<CharType, int>(str, after_str, was_overflow, allow_skip_whitechars);
}


}


#endif