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

#import "MPFactor.h"
#import "MPMathRules.h"

@implementation MPFactor {
    NSRange _multiplicationSymbolRange;
}

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

- (instancetype)initWithTokenStream:(MPTokenStream *)tokenStream
{
    self = [self init];
    if (self) {
        [tokenStream beginIgnoringWhitespaceTokens];
        MPToken *token = tokenStream.currentToken;
        if (token.tokenType == MPMultiplicationSymbolToken) {
            _multiplicationSymbolRange = token.range;
            [tokenStream currentTokenConsumed];
        } else {
            _multiplicationSymbolRange = NSMakeRange(NSNotFound, 0);
        }
        if (tokenStream.currentToken.tokenType == MPOperatorListToken) {
            _operatorChain = [[MPOperatorChain alloc] initWithTokenStream:tokenStream];
        }
        MPValueGroup *valueGroup = [[MPValueGroup alloc] initWithTokenStream:tokenStream];
        _value = [tokenStream consumeSuffixesForValue:valueGroup];
        [tokenStream endIgnoringOrAcceptingWhitespaceTokens];
    }
    return self;
}

- (NSRange)range
{
    if (_multiplicationSymbolRange.location == NSNotFound) {
        return self.value.range;
    }
    return NSUnionRange(_multiplicationSymbolRange, self.value.range);
}

- (NSRange)multiplicationSymbolRange
{
    return _multiplicationSymbolRange;
}

- (BOOL)hasMultiplicationSymbol
{
    return _multiplicationSymbolRange.location != NSNotFound;
}

- (BOOL)validate:(MPParseError *__autoreleasing *)error
{
    if (self.operatorChain.numberOfOperators > [[MPMathRules sharedRules] maximumOperatorChainLengthInMultiplication]) {
        if (error) {
            *error = MPParseError(self.operatorChain.range, @"Too many operators in Multiplication");
        }
        return NO;
    }
    return [self.value validate:error];
}

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

- (NSArray *)expressionElements
{
    NSMutableArray *elements = [[NSMutableArray alloc] init];
    if (self.hasMultiplicationSymbol) {
        [elements addObject:@"*"];
    }
    [elements addObjectsFromArray:self.value.expressionElements];
    return elements;
}

@end