/** 
   NSDecimalNumber class
   Copyright (C) 2000 Free Software Foundation, Inc.

   Written by: Fred Kiefer <FredKiefer@gmx.de>
   Created: July 2000

   This file is part of the GNUstep Base Library.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA.

   <title>NSDecimalNumber class reference</title>
   $Date$ $Revision$
   */

#include <Foundation/NSException.h>
#include <Foundation/NSDecimal.h>
#include <Foundation/NSDecimalNumber.h>
#include "GSPrivate.h"

static NSDecimalNumberHandler *handler;
 
@implementation NSDecimalNumberHandler

+ (id) defaultDecimalNumberHandler
{
  if (handler == nil)
    handler = [[self alloc] initWithRoundingMode: NSRoundPlain
			    scale: 38
			    raiseOnExactness: NO
			    raiseOnOverflow: YES
			    raiseOnUnderflow: YES
			    raiseOnDivideByZero: YES];

  return handler;
}

+ (id) decimalNumberHandlerWithRoundingMode: (NSRoundingMode)roundingMode 
				      scale: (short)scale
			   raiseOnExactness: (BOOL)raiseOnExactness 
			    raiseOnOverflow: (BOOL)raiseOnOverflow 
			   raiseOnUnderflow: (BOOL)raiseOnUnderflow
			raiseOnDivideByZero: (BOOL)raiseOnDivideByZero
{
  return AUTORELEASE([[self alloc] initWithRoundingMode: roundingMode 
				   scale: scale 
				   raiseOnExactness: raiseOnExactness
				   raiseOnOverflow: raiseOnOverflow 
				   raiseOnUnderflow: raiseOnUnderflow
				   raiseOnDivideByZero: raiseOnDivideByZero]);
}

- (id) initWithRoundingMode: (NSRoundingMode)roundingMode 
		      scale: (short)scale 
	   raiseOnExactness: (BOOL)raiseOnExactness
	    raiseOnOverflow: (BOOL)raiseOnOverflow 
	   raiseOnUnderflow: (BOOL)raiseOnUnderflow
	raiseOnDivideByZero: (BOOL)raiseOnDivideByZero
{
  _roundingMode = roundingMode;
  _scale = scale;
  _raiseOnExactness = raiseOnExactness;
  _raiseOnOverflow = raiseOnOverflow; 
  _raiseOnUnderflow = raiseOnUnderflow;
  _raiseOnDivideByZero = raiseOnDivideByZero;

  return self;
}

- (NSDecimalNumber*) exceptionDuringOperation: (SEL)method 
					error: (NSCalculationError)error 
				  leftOperand: (NSDecimalNumber*)leftOperand 
				 rightOperand: (NSDecimalNumber*)rightOperand
{
  switch (error)
    {
      case NSCalculationNoError: return nil;
      case NSCalculationUnderflow: 
	if (_raiseOnUnderflow)
	  // FIXME: What exception to raise?
	  [NSException raise: @"NSDecimalNumberException"
		      format: @"Underflow"];
	else
	  return [NSDecimalNumber minimumDecimalNumber];
	break;
      case NSCalculationOverflow: 
	if (_raiseOnOverflow)
	  [NSException raise: @"NSDecimalNumberException"
		      format: @"Overflow"];
	else
	  return [NSDecimalNumber maximumDecimalNumber];
	break;
      case NSCalculationLossOfPrecision: 
	if (_raiseOnExactness)
	  [NSException raise: @"NSDecimalNumberException"
		      format: @"Loss of precision"];
	else
	  return nil;
	break;
      case NSCalculationDivideByZero: 
	if (_raiseOnDivideByZero)
	  [NSException raise: @"NSDecimalNumberException"
		      format: @"Divide by zero"];
	else
	  return [NSDecimalNumber notANumber];
	break;
    }

  return nil;
}

- (NSRoundingMode) roundingMode
{
  return _roundingMode;
}

- (short) scale
{
  return _scale;
}

@end


@implementation NSDecimalNumber

static NSDecimalNumber *maxNumber;
static NSDecimalNumber *minNumber;
static NSDecimalNumber *notANumber;
static NSDecimalNumber *zero;
static NSDecimalNumber *one;

+ (void) initialize
{
  NSDecimal d;

  d.validNumber = NO;
  notANumber = [[self alloc] initWithDecimal: d];
  NSDecimalMax(&d);
  maxNumber = [[self alloc] initWithDecimal: d];
  NSDecimalMin(&d);
  minNumber = [[self alloc] initWithDecimal: d];
  zero = [[self alloc] initWithMantissa: 0
			       exponent: 0
			     isNegative: NO];
  one = [[self alloc] initWithMantissa: 1
			      exponent: 0
			    isNegative: NO];
}

+ (id <NSDecimalNumberBehaviors>) defaultBehavior
{
  // Reuse the handler from the class NSDecimalNumberHandler
  return [NSDecimalNumberHandler defaultDecimalNumberHandler];
}

+ (void) setDefaultBehavior: (id <NSDecimalNumberBehaviors>)behavior
{
  // Reuse the handler from the class NSDecimalNumberHandler
  // Might give interessting result on this class as behavior may came 
  // from a different class
  ASSIGN(handler, behavior);
}

+ (NSDecimalNumber*) maximumDecimalNumber
{
  return maxNumber;
}
+ (NSDecimalNumber*) minimumDecimalNumber
{
  return minNumber;
}

+ (NSDecimalNumber*) notANumber
{
  return notANumber;
}

+ (NSDecimalNumber*) zero
{
  return zero;
}

+ (NSDecimalNumber*) one
{
  return one;
}

+ (NSDecimalNumber*) decimalNumberWithDecimal: (NSDecimal)decimal
{
  return AUTORELEASE([[self alloc] initWithDecimal: decimal]);
}

+ (NSDecimalNumber*) decimalNumberWithMantissa: (unsigned long long)mantissa 
				      exponent: (short)exponent
				    isNegative: (BOOL)isNegative
{
  return AUTORELEASE([[self alloc] initWithMantissa: mantissa 
					   exponent: exponent
					 isNegative: isNegative]);
}

+ (NSDecimalNumber*) decimalNumberWithString: (NSString*)numericString
{
  return AUTORELEASE([[self alloc] initWithString: numericString]);
}

+ (NSDecimalNumber*) decimalNumberWithString: (NSString*)numericString 
				      locale: (NSDictionary*)locale
{
  return AUTORELEASE([[self alloc] initWithString: numericString
					   locale: locale]);
}

/**
 * Inefficient ... quick hack by converting double value to string,
 * then initialising from string.
 */
- (id) initWithBytes: (const void*)value objCType: (const char*)type
{
  double	tmp;
  NSString	*s;

  memcpy(&tmp, value, sizeof(tmp));
  s = [[NSString alloc] initWithFormat: @"%g", tmp];
  self = [self initWithString: s];
  RELEASE(s);
  return self;
}

- (id) initWithDecimal: (NSDecimal)decimal
{
  NSDecimalCopy(&data, &decimal);
  return self;
}

- (id) initWithMantissa: (unsigned long long)mantissa 
	       exponent: (short)exponent 
	     isNegative: (BOOL)flag
{
  NSDecimal decimal;

  NSDecimalFromComponents(&decimal, mantissa, exponent, flag);
  return [self initWithDecimal: decimal];
}

- (id) initWithString: (NSString*)numberValue
{
  return [self initWithString: numberValue 
		       locale: GSUserDefaultsDictionaryRepresentation()];
}

- (id) initWithString: (NSString*)numberValue 
	       locale: (NSDictionary*)locale
{
  NSDecimal decimal;

  NSDecimalFromString(&decimal, numberValue, locale);
  return [self initWithDecimal: decimal];
}

- (id) initWithBool: (BOOL)value
{
  return [self initWithMantissa: (value == YES) ? 1 : 0
		       exponent: 0
		     isNegative: NO];
}

- (id) initWithChar: (signed char)value
{
  if (value < 0)
    {
      return [self initWithMantissa: -value
			   exponent: 0
			 isNegative: YES];
    }
  else
    {
      return [self initWithMantissa: value
			   exponent: 0
			 isNegative: NO];
    }
}

- (id) initWithDouble: (double)value
{
  return [self initWithBytes: &value objCType: "d"];
}

- (id) initWithFloat: (float)value
{
  double	d = (double)value;

  return [self initWithBytes: &d objCType: "d"];
}

- (id) initWithInt: (signed int)value
{
  if (value < 0)
    {
      return [self initWithMantissa: -value
			   exponent: 0
			 isNegative: YES];
    }
  else
    {
      return [self initWithMantissa: value
			   exponent: 0
			 isNegative: NO];
    }
}

- (id) initWithLong: (signed long)value
{
  if (value < 0)
    {
      return [self initWithMantissa: -value
			   exponent: 0
			 isNegative: YES];
    }
  else
    {
      return [self initWithMantissa: value
			   exponent: 0
			 isNegative: NO];
    }
}

- (id) initWithLongLong: (signed long long)value
{
  if (value < 0)
    {
      return [self initWithMantissa: -value
			   exponent: 0
			 isNegative: YES];
    }
  else
    {
      return [self initWithMantissa: value
			   exponent: 0
			 isNegative: NO];
    }
}

- (id) initWithShort: (signed short)value
{
  if (value < 0)
    {
      return [self initWithMantissa: -value
			   exponent: 0
			 isNegative: YES];
    }
  else
    {
      return [self initWithMantissa: value
			   exponent: 0
			 isNegative: NO];
    }
}

- (id) initWithUnsignedChar: (unsigned char)value
{
  return [self initWithMantissa: value
		       exponent: 0
		     isNegative: NO];
}

- (id) initWithUnsignedInt: (unsigned int)value
{
  return [self initWithMantissa: value
		       exponent: 0
		     isNegative: NO];
}

- (id) initWithUnsignedLong: (unsigned long)value
{
  return [self initWithMantissa: value
		       exponent: 0
		     isNegative: NO];
}

- (id) initWithUnsignedLongLong: (unsigned long long)value
{
  return [self initWithMantissa: value
		       exponent: 0
		     isNegative: NO];
}

- (id) initWithUnsignedShort: (unsigned short)value
{
  return [self initWithMantissa: value
		       exponent: 0
		     isNegative: NO];
}

- (NSString*) descriptionWithLocale: (NSDictionary*)locale
{
  return NSDecimalString(&data, locale);
}

- (const char*) objCType
{
  return "d";
}

- (NSDecimal) decimalValue
{
  NSDecimal decimal;
  
  NSDecimalCopy(&decimal, &data);
  return decimal;
}

- (double) doubleValue
{
  return NSDecimalDouble(&data);
}

/**
 * Get the approximate value of the decimal number into a buffer
 * as a double.
 */
- (void) getValue: (void*)buffer
{
  double	tmp = NSDecimalDouble(&data);

  memcpy(buffer, &tmp, sizeof(tmp));
}

- (NSComparisonResult) compare: (NSNumber*)decimalNumber
{
  if ([decimalNumber isMemberOfClass: [self class]])
    {
      NSDecimal d1 = [self decimalValue];
      NSDecimal d2 = [(NSDecimalNumber*)decimalNumber decimalValue];

      return NSDecimalCompare(&d1, &d2);
    }
  else
    return [super compare: decimalNumber];
}

- (NSDecimalNumber*) decimalNumberByAdding: (NSDecimalNumber*)decimalNumber
{
  return [self decimalNumberByAdding: decimalNumber 
			withBehavior: [isa defaultBehavior]];
}

- (NSDecimalNumber*) decimalNumberByAdding: (NSDecimalNumber*)decimalNumber 
  withBehavior: (id<NSDecimalNumberBehaviors>)behavior
{
  NSDecimal result;
  NSDecimal d1 = [self decimalValue];
  NSDecimal d2 = [decimalNumber decimalValue];
  NSCalculationError error;
  NSDecimalNumber *res;

  error = NSDecimalAdd(&result, &d1, &d2, [behavior roundingMode]);
  if (error)
    {
      res = [behavior exceptionDuringOperation: _cmd 
					 error: error 
				   leftOperand: self 
				  rightOperand: decimalNumber];
      if (res != nil)
	return res;
    }
  
  return [NSDecimalNumber decimalNumberWithDecimal: result];
}

- (NSDecimalNumber*) decimalNumberBySubtracting: (NSDecimalNumber*)decimalNumber
{
  return [self decimalNumberBySubtracting: decimalNumber 
			     withBehavior: [isa defaultBehavior]];
}

- (NSDecimalNumber*) decimalNumberBySubtracting: (NSDecimalNumber*)decimalNumber
  withBehavior: (id <NSDecimalNumberBehaviors>)behavior
{
  NSDecimal result;
  NSDecimal d1 = [self decimalValue];
  NSDecimal d2 = [decimalNumber decimalValue];
  NSCalculationError error;
  NSDecimalNumber *res;

  error = NSDecimalSubtract(&result, &d1, &d2, [behavior roundingMode]);
  if (error)
    {
      res = [behavior exceptionDuringOperation: _cmd 
					 error: error 
				   leftOperand: self 
				  rightOperand: decimalNumber];
      if (res != nil)
	return res;
    }
  
  return [NSDecimalNumber decimalNumberWithDecimal: result];
}

- (NSDecimalNumber*) decimalNumberByMultiplyingBy:
  (NSDecimalNumber*)decimalNumber
{
  return [self decimalNumberByMultiplyingBy: decimalNumber 
			       withBehavior: [isa defaultBehavior]];
}

- (NSDecimalNumber*) decimalNumberByMultiplyingBy:
  (NSDecimalNumber*)decimalNumber 
  withBehavior: (id <NSDecimalNumberBehaviors>)behavior
{
  NSDecimal result;
  NSDecimal d1 = [self decimalValue];
  NSDecimal d2 = [decimalNumber decimalValue];
  NSCalculationError error;
  NSDecimalNumber *res;

  error = NSDecimalMultiply(&result, &d1, &d2, [behavior roundingMode]);
  if (error)
    {
      res = [behavior exceptionDuringOperation: _cmd 
					 error: error 
				   leftOperand: self 
				  rightOperand: decimalNumber];
      if (res != nil)
	return res;
    }
  
  return [NSDecimalNumber decimalNumberWithDecimal: result];
}

- (NSDecimalNumber*) decimalNumberByDividingBy: (NSDecimalNumber*)decimalNumber
{
  return [self decimalNumberByDividingBy: decimalNumber 
			    withBehavior: [isa defaultBehavior]];
}

- (NSDecimalNumber*) decimalNumberByDividingBy: (NSDecimalNumber*)decimalNumber 
  withBehavior: (id <NSDecimalNumberBehaviors>)behavior
{
  NSDecimal result;
  NSDecimal d1 = [self decimalValue];
  NSDecimal d2 = [decimalNumber decimalValue];
  NSCalculationError error;
  NSDecimalNumber *res;

  error = NSDecimalDivide(&result, &d1, &d2, [behavior roundingMode]);
  if (error)
    {
      res = [behavior exceptionDuringOperation: _cmd 
					 error: error 
				   leftOperand: self 
				  rightOperand: decimalNumber];
      if (res != nil)
	return res;
    }
  
  return [NSDecimalNumber decimalNumberWithDecimal: result];
}

- (NSDecimalNumber*) decimalNumberByMultiplyingByPowerOf10: (short)power
{
  return [self decimalNumberByMultiplyingByPowerOf10: power 
					withBehavior: [isa defaultBehavior]];
}

- (NSDecimalNumber*) decimalNumberByMultiplyingByPowerOf10: (short)power 
  withBehavior: (id <NSDecimalNumberBehaviors>)behavior
{
  NSDecimal result;
  NSDecimal d1 = [self decimalValue];
  NSCalculationError error;
  NSDecimalNumber *res;

  error = NSDecimalMultiplyByPowerOf10(&result, &d1, 
    power, [behavior roundingMode]);
  if (error)
    {
      res = [behavior exceptionDuringOperation: _cmd 
					 error: error 
				   leftOperand: self 
				  rightOperand: nil];
      if (res != nil)
	return res;
    }
  
  return [NSDecimalNumber decimalNumberWithDecimal: result];
}

- (NSDecimalNumber*) decimalNumberByRaisingToPower: (unsigned)power
{
  return [self decimalNumberByRaisingToPower: power 
				withBehavior: [isa defaultBehavior]];
}

- (NSDecimalNumber*) decimalNumberByRaisingToPower: (unsigned)power 
  withBehavior: (id <NSDecimalNumberBehaviors>)behavior
{
  NSDecimal result;
  NSDecimal d1 = [self decimalValue];
  NSCalculationError error;
  NSDecimalNumber *res;

  error = NSDecimalPower(&result, &d1, 
    power, [behavior roundingMode]);
  if (error)
    {
      res = [behavior exceptionDuringOperation: _cmd 
					 error: error 
				   leftOperand: self 
				  rightOperand: nil];
      if (res != nil)
	return res;
    }
  
  return [NSDecimalNumber decimalNumberWithDecimal: result];
}

- (NSDecimalNumber*) decimalNumberByRoundingAccordingToBehavior:
  (id <NSDecimalNumberBehaviors>)behavior
{
  NSDecimal result;
  NSDecimal d1 = [self decimalValue];

  NSDecimalRound(&result, &d1, [behavior scale], [behavior roundingMode]);
  return [NSDecimalNumber decimalNumberWithDecimal: result];
}


// Methods for NSDecimalNumberBehaviors
- (NSDecimalNumber*) exceptionDuringOperation: (SEL)method 
					error: (NSCalculationError)error 
				  leftOperand: (NSDecimalNumber*)leftOperand 
				 rightOperand: (NSDecimalNumber*)rightOperand
{
  return [[isa defaultBehavior] exceptionDuringOperation: method 
						   error: error 
					     leftOperand: leftOperand 
					    rightOperand: rightOperand];
}

- (NSRoundingMode) roundingMode
{
  return [[isa defaultBehavior] roundingMode];
}

- (short) scale
{
  return [[isa defaultBehavior] scale];
}

@end

@implementation NSNumber (NSDecimalNumber)
/** Returns an NSDecimal representation of the number. Float and double
    values may not be converted exactly */
- (NSDecimal) decimalValue
{
  double num;
  NSDecimalNumber *dnum;
  num = [self doubleValue];
  dnum = [[NSDecimalNumber alloc] initWithBytes: &num objCType: "d"];
  AUTORELEASE(dnum);
  return [dnum decimalValue];
}
@end