/*
 * CPNumberFormatter.j
 * Foundation
 *
 * Created by Alexander Ljungberg.
 * Copyright 2011, WireLoad Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

@import "CPString.j"
@import "CPFormatter.j"
@import "CPDecimalNumber.j"

@typedef CPNumberFormatterStyle
CPNumberFormatterNoStyle            = 0;
CPNumberFormatterDecimalStyle       = 1;
CPNumberFormatterCurrencyStyle      = 2;
CPNumberFormatterPercentStyle       = 3;
CPNumberFormatterScientificStyle    = 4;
CPNumberFormatterSpellOutStyle      = 5;

@typedef CPNumberFormatterRoundingMode
CPNumberFormatterRoundCeiling       = CPRoundUp;
CPNumberFormatterRoundFloor         = CPRoundDown;
CPNumberFormatterRoundDown          = CPRoundDown;
CPNumberFormatterRoundUp            = CPRoundUp;
CPNumberFormatterRoundHalfEven      = CPRoundBankers;
CPNumberFormatterRoundHalfDown      = _CPRoundHalfDown;
CPNumberFormatterRoundHalfUp        = CPRoundPlain;

var NumberRegex = new RegExp('(-)?(\\d*)(\\.(\\d*))?');

#define SET_NEEDS_NUMBER_HANDLER_UPDATE() _numberHandler = nil


/*!
    @ingroup foundation
    @class CPNumberFormatter

    CPNumberFormatter takes a numeric CPNumber value and formats it as text for
    display. It also supports the converse, taking text and interpreting it as a
    CPNumber by configurable formatting rules.
*/
@implementation CPNumberFormatter : CPFormatter
{
    CPNumberFormatterStyle          _numberStyle @accessors(property=numberStyle);
    CPString                        _perMillSymbol @accessors(property=perMillSymbol);
    CPString                        _groupingSeparator @accessors(property=groupingSeparator);
    CPNumberFormatterRoundingMode   _roundingMode @accessors(property=roundingMode);
    CPUInteger                      _minimumFractionDigits @accessors(property=minimumFractionDigits);
    CPUInteger                      _maximumFractionDigits @accessors(property=maximumFractionDigits);
    CPUInteger                      _minimum @accessors(property=minimum);
    CPUInteger                      _maximum @accessors(property=maximum);
    CPString                        _currencyCode @accessors(property=currencyCode);
    CPString                        _currencySymbol @accessors(property=currencySymbol);
    BOOL                            _generatesDecimalNumbers @accessors(property=generatesDecimalNumbers);

    // Note that we do not implement the 10.0 style number formatter, but the 10.4+ formatter. Therefore
    // we don't expose this through a `roundingBehavior` property.
    CPDecimalNumberHandler         _numberHandler;
}

- (id)init
{
    if (self = [super init])
    {
        _roundingMode = CPNumberFormatterRoundHalfEven;
        _minimumFractionDigits = 0;
        _maximumFractionDigits = 0;
        _groupingSeparator = @",";
        _generatesDecimalNumbers = YES;
        _minimum = nil;
        _maximum = nil;

        // FIXME Add locale support.
        _currencyCode = @"USD";
        _currencySymbol = @"$";
    }

    return self;
}

- (CPString)stringFromNumber:(CPNumber)number
{
    if (_numberStyle == CPNumberFormatterPercentStyle)
    {
        number *= 100.0;
    }

    var dcmn = [number isKindOfClass:CPDecimalNumber] ? number : [[CPDecimalNumber alloc] _initWithJSNumber:number];

    // TODO Add locale support.
    switch (_numberStyle)
    {
        case CPNumberFormatterCurrencyStyle:
        case CPNumberFormatterDecimalStyle:
        case CPNumberFormatterPercentStyle:
            [self _updateNumberHandlerIfNecessary];

            dcmn = [dcmn decimalNumberByRoundingAccordingToBehavior:_numberHandler];

            var output = [dcmn descriptionWithLocale:nil],
                // FIXME this is probably locale dependent.
                parts = output.match(NumberRegex) || ["", undefined, "", undefined, undefined],
                negativePrefix = parts[1] || "",
                preFraction = parts[2] || "",
                fraction = parts[4] || "",
                preFractionLength = [preFraction length],
                commaPosition = 3;

            while (fraction.length < _minimumFractionDigits)
                fraction += "0";

            // TODO This is just a temporary solution. Should be generalised.
            // Add in thousands separators.
            if (_groupingSeparator)
            {
                for (var commaPosition = 3, prefLength = [preFraction length]; commaPosition < prefLength; commaPosition += 4)
                {
                    preFraction = [preFraction stringByReplacingCharactersInRange:CPMakeRange(prefLength - commaPosition, 0) withString:_groupingSeparator];
                    prefLength += 1;
                }
            }

            var string = preFraction;

            if (fraction)
                string += "." + fraction;

            if (_numberStyle === CPNumberFormatterCurrencyStyle)
            {
                if (_currencySymbol)
                    string = _currencySymbol + string;
                else
                    string = _currencyCode + string;
            }

            if (_numberStyle == CPNumberFormatterPercentStyle)
                string += "%";

            if (negativePrefix)
                string = negativePrefix + string;

            return string;

        default:
            return [number description];
    }
}

+ (CPString)localizedStringFromNumber:(CPNumber)num numberStyle:(CPNumberFormatterStyle)localizationStyle
{
    var formatter = [[CPNumberFormatter alloc] init];
    [formatter setNumberStyle:localizationStyle];

    return [formatter stringFromNumber:num];
}

- (CPNumber)numberFromString:(CPString)aString
{
    if (_generatesDecimalNumbers)
        return [CPDecimalNumber decimalNumberWithString:aString];
    else
        return parseFloat(aString);
}

- (CPString)stringForObjectValue:(id)anObject
{
    if ([anObject isKindOfClass:[CPNumber class]])
        return [self stringFromNumber:anObject];
    else
        return [anObject description];
}

- (CPString)editingStringForObjectValue:(id)anObject
{
    return [self stringForObjectValue:anObject];
}

- (BOOL)getObjectValue:(idRef)anObjectRef forString:(CPString)aString errorDescription:(CPStringRef)anErrorRef
{
    // Interpret an empty string as nil, like in Cocoa.
    if (aString === @"")
    {
        @deref(anObjectRef) = nil;
        return YES;
    }

    var value = [self numberFromString:aString],
        error = @"";

    // this will return false if we've received anything but a number, most likely NaN
    if (!isFinite(value))
        error = @"Value is not a number";
    else if (_minimum !== nil && value < _minimum)
        error = @"Value is less than the minimum allowed value";
    else if (_maximum !== nil && value > _maximum)
        error = @"Value is greater than the maximum allowed value";

    if (error)
    {
        if (anErrorRef)
            @deref(anErrorRef) = error;

        return NO;
    }

    @deref(anObjectRef) = value;

    return YES;
}

- (void)setNumberStyle:(CPNumberFormatterStyle)aStyle
{
    _numberStyle = aStyle;

    switch (aStyle)
    {
        case CPNumberFormatterDecimalStyle:
            _minimumFractionDigits = 0;
            _maximumFractionDigits = 3;
            SET_NEEDS_NUMBER_HANDLER_UPDATE();
            break;

        case CPNumberFormatterCurrencyStyle:
            _minimumFractionDigits = 2;
            _maximumFractionDigits = 2;
            SET_NEEDS_NUMBER_HANDLER_UPDATE();
            break;
    }
}

- (void)setRoundingMode:(CPNumberFormatterRoundingMode)aRoundingMode
{
    _roundingMode = aRoundingMode;
    SET_NEEDS_NUMBER_HANDLER_UPDATE();
}

- (void)setMinimumFractionDigits:(CPUInteger)aNumber
{
    _minimumFractionDigits = aNumber;
    SET_NEEDS_NUMBER_HANDLER_UPDATE();
}

- (void)setMaximumFractionDigits:(CPUInteger)aNumber
{
    _maximumFractionDigits = aNumber;
    SET_NEEDS_NUMBER_HANDLER_UPDATE();
}

- (void)setMinimum:(CPUInteger)aNumber
{
    _minimum = aNumber;
    SET_NEEDS_NUMBER_HANDLER_UPDATE();
}

- (void)setMaximum:(CPUInteger)aNumber
{
    _maximum = aNumber;
    SET_NEEDS_NUMBER_HANDLER_UPDATE();
}

#pragma mark Private

- (void)_updateNumberHandlerIfNecessary
{
    if (!_numberHandler)
        _numberHandler = [CPDecimalNumberHandler decimalNumberHandlerWithRoundingMode:_roundingMode
                                                                                scale:_maximumFractionDigits
                                                                     raiseOnExactness:NO
                                                                      raiseOnOverflow:NO
                                                                     raiseOnUnderflow:NO
                                                                  raiseOnDivideByZero:YES];
}

@end

var CPNumberFormatterStyleKey                   = @"CPNumberFormatterStyleKey",
    CPNumberFormatterMinimumFractionDigitsKey   = @"CPNumberFormatterMinimumFractionDigitsKey",
    CPNumberFormatterMaximumFractionDigitsKey   = @"CPNumberFormatterMaximumFractionDigitsKey",
    CPNumberFormatterMinimumKey                 = @"CPNumberFormatterMinimumKey",
    CPNumberFormatterMaximumKey                 = @"CPNumberFormatterMaximumKey",
    CPNumberFormatterRoundingModeKey            = @"CPNumberFormatterRoundingModeKey",
    CPNumberFormatterGroupingSeparatorKey       = @"CPNumberFormatterGroupingSeparatorKey",
    CPNumberFormatterCurrencyCodeKey            = @"CPNumberFormatterCurrencyCodeKey",
    CPNumberFormatterCurrencySymbolKey          = @"CPNumberFormatterCurrencySymbolKey",
    CPNumberFormatterGeneratesDecimalNumbers    = @"CPNumberFormatterGeneratesDecimalNumbers";

@implementation CPNumberFormatter (CPCoding)

- (id)initWithCoder:(CPCoder)aCoder
{
    self = [super initWithCoder:aCoder];

    if (self)
    {
        _numberStyle = [aCoder decodeIntForKey:CPNumberFormatterStyleKey];
        _minimumFractionDigits = [aCoder decodeIntForKey:CPNumberFormatterMinimumFractionDigitsKey];
        _maximumFractionDigits = [aCoder decodeIntForKey:CPNumberFormatterMaximumFractionDigitsKey];
        _roundingMode = [aCoder decodeIntForKey:CPNumberFormatterRoundingModeKey];
        _groupingSeparator = [aCoder decodeObjectForKey:CPNumberFormatterGroupingSeparatorKey];
        _currencyCode = [aCoder decodeObjectForKey:CPNumberFormatterCurrencyCodeKey];
        _currencySymbol = [aCoder decodeObjectForKey:CPNumberFormatterCurrencySymbolKey];
        _generatesDecimalNumbers = [aCoder decodeBoolForKey:CPNumberFormatterGeneratesDecimalNumbers];

        // We decode _minimum and _maximum as object here because otherwise, nil values are not preserved
        // causing a min and max always set to 0 after an decoding.
        _minimum = [aCoder decodeObjectForKey:CPNumberFormatterMinimumKey];
        _maximum = [aCoder decodeObjectForKey:CPNumberFormatterMaximumKey];
    }

    return self;
}

- (void)encodeWithCoder:(CPCoder)aCoder
{
    [super encodeWithCoder:aCoder];

    [aCoder encodeInt:_numberStyle forKey:CPNumberFormatterStyleKey];
    [aCoder encodeInt:_minimumFractionDigits forKey:CPNumberFormatterMinimumFractionDigitsKey];
    [aCoder encodeInt:_maximumFractionDigits forKey:CPNumberFormatterMaximumFractionDigitsKey];
    [aCoder encodeInt:_minimum forKey:CPNumberFormatterMinimumKey];
    [aCoder encodeInt:_maximum forKey:CPNumberFormatterMaximumKey];
    [aCoder encodeInt:_roundingMode forKey:CPNumberFormatterRoundingModeKey];
    [aCoder encodeObject:_groupingSeparator forKey:CPNumberFormatterGroupingSeparatorKey];
    [aCoder encodeObject:_currencyCode forKey:CPNumberFormatterCurrencyCodeKey];
    [aCoder encodeObject:_currencySymbol forKey:CPNumberFormatterCurrencySymbolKey];
    [aCoder encodeBool:_generatesDecimalNumbers forKey:CPNumberFormatterGeneratesDecimalNumbers];
}

@end