/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2012, assimp team
All rights reserved.

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with or without modification, are permitted provided that the 
following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* 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.

* Neither the name of the assimp team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the assimp team.

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 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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----------------------------------------------------------------------
*/

/** @file Definition of platform independent string workers:

   ASSIMP_itoa10
   ASSIMP_stricmp
   ASSIMP_strincmp

   These functions are not consistently available on all platforms,
   or the provided implementations behave too differently.
*/
#ifndef INCLUDED_AI_STRING_WORKERS_H
#define INCLUDED_AI_STRING_WORKERS_H

#include "../include/assimp/ai_assert.h"

namespace Assimp	{

// -------------------------------------------------------------------------------
/** @brief itoa with a fixed base 10
 * 'itoa' is not consistently available on all platforms so it is quite useful
 * to have a small replacement function here. No need to use a full sprintf()
 * if we just want to print a number ...
 * @param out Output buffer
 * @param max Maximum number of characters to be written, including '\0'.
 *   This parameter may not be 0.
 * @param number Number to be written
 * @return Length of the output string, excluding the '\0'
 */
inline unsigned int ASSIMP_itoa10( char* out, unsigned int max, int32_t number)
{
	ai_assert(NULL != out);

	// write the unary minus to indicate we have a negative number
	unsigned int written = 1u;
	if (number < 0 && written < max)	{
		*out++ = '-';
		++written;
		number = -number;
	}

	// We begin with the largest number that is not zero. 
	int32_t cur = 1000000000; // 2147483648
	bool mustPrint = false;
	while (written < max)	{

		const unsigned int digit = number / cur;
		if (mustPrint || digit > 0 || 1 == cur)	{
			// print all future zeroes from now
			mustPrint = true;	

			*out++ = '0'+static_cast<char>(digit);

			++written;
			number -= digit*cur;
			if (1 == cur) {
				break;
			}
		}
		cur /= 10;
	}

	// append a terminal zero
	*out++ = '\0';
	return written-1;
}

// -------------------------------------------------------------------------------
/** @brief itoa with a fixed base 10 (Secure template overload)
 *  The compiler should choose this function if he or she is able to determine the
 *  size of the array automatically.
 */
template <size_t length>
inline unsigned int ASSIMP_itoa10( char(& out)[length], int32_t number)
{
	return ASSIMP_itoa10(out,length,number);
}

// -------------------------------------------------------------------------------
/** @brief Helper function to do platform independent string comparison.
 *
 *  This is required since stricmp() is not consistently available on
 *  all platforms. Some platforms use the '_' prefix, others don't even
 *  have such a function. 
 *
 *  @param s1 First input string
 *  @param s2 Second input string
 *  @return 0 if the given strings are identical
 */
inline int ASSIMP_stricmp(const char *s1, const char *s2)
{
	ai_assert(NULL != s1 && NULL != s2);

#if (defined _MSC_VER)

	return ::_stricmp(s1,s2);
#elif defined( __GNUC__ )
	
	return ::strcasecmp(s1,s2);
#else
	
	register char c1, c2;
	do	{
		c1 = tolower(*s1++);
		c2 = tolower(*s2++);
	} 
	while ( c1 && (c1 == c2) );
	return c1 - c2;
#endif
}

// -------------------------------------------------------------------------------
/** @brief Case independent comparison of two std::strings
 *
 *  @param a First  string
 *  @param b Second string
 *  @return 0 if a == b
 */
inline int ASSIMP_stricmp(const std::string& a, const std::string& b)
{
	register int i = (int)b.length()-(int)a.length();
	return (i ? i : ASSIMP_stricmp(a.c_str(),b.c_str()));
}

// -------------------------------------------------------------------------------
/** @brief Helper function to do platform independent string comparison.
 *
 *  This is required since strincmp() is not consistently available on
 *  all platforms. Some platforms use the '_' prefix, others don't even
 *  have such a function. 
 *
 *  @param s1 First input string
 *  @param s2 Second input string
 *  @param n Macimum number of characters to compare
 *  @return 0 if the given strings are identical
 */
inline int ASSIMP_strincmp(const char *s1, const char *s2, unsigned int n)
{
	ai_assert(NULL != s1 && NULL != s2);
	if (!n)return 0;

#if (defined _MSC_VER)

	return ::_strnicmp(s1,s2,n);

#elif defined( __GNUC__ )

	return ::strncasecmp(s1,s2, n);

#else
	register char c1, c2;
	unsigned int p = 0;
	do 
	{
		if (p++ >= n)return 0;
		c1 = tolower(*s1++);
		c2 = tolower(*s2++);
	} 
	while ( c1 && (c1 == c2) );

	return c1 - c2;
#endif
}


// -------------------------------------------------------------------------------
/** @brief Evaluates an integer power
 *
 * todo: move somewhere where it fits better in than here 
 */
inline unsigned int integer_pow (unsigned int base, unsigned int power)
{
	unsigned int res = 1;
	for (unsigned int i = 0; i < power;++i)
		res *= base;

	return res;
}
} // end of namespace

#endif // !  AI_STRINGCOMPARISON_H_INC
