//
//  MPSummand.m
//  MathPad
//
//  Created by Kim Wittenburg on 09.10.14.
//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
//

#import "MPSummand.h"
#import "MPMathRules.h"

@implementation MPSummand

- (id)init
{
    self = [super init];
    if (self) {
    }
    return self;
}

- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
{
    self = [self init];
    if (self) {
        [tokenStream beginIgnoringWhitespaceTokens];
        if (tokenStream.currentToken.tokenType == MPOperatorListToken) {
            _operatorChain = [[MPOperatorChain alloc] initWithTokenStream:tokenStream];
        }
        _product = [[MPProduct alloc] initWithTokenStream:tokenStream];
        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
    }
    return self;
}

- (BOOL)validate:(NSError *__autoreleasing *)error
{
    if (self.operatorChain.numberOfOperators > [MPMathRules sharedRules].maximumOperatorChainLength) {
        if (error) {
            *error = MPParseError(4,
                                  NSLocalizedString(@"Too many operators.", @"Error message. This is displayed when there are too many subsequent operators in an expression."),
                                  nil);
        }
        return NO;
    }
    return [self.product validate:error];
}

- (NSDecimalNumber *)evaluate
{
    NSDecimalNumber *value = [self.product evaluate];
    if ([value isNotEqualTo:[NSDecimalNumber notANumber]] && self.operatorChain) {
        value = [value decimalNumberByMultiplyingBy:[self.operatorChain evaluate]];
    }
    return value;
}

@end