#import "NNArrayDiffChange.h"

@implementation NNArrayDiffChange

#pragma mark - Init

- (instancetype)init {

return [self initWithBefore:NSNotFound after:NSNotFound type:0];

}

- (instancetype)initWithBefore:(NSUInteger)before after:(NSUInteger)after type:(NNDiffChangeType)type {

NSParameterAssert(before != NSNotFound);

NSParameterAssert(after != NSNotFound);

NSParameterAssert(type != 0);

self = [super init];

if (!self) return nil;

_before = before;

_after = after;

_type = type;

return self;

}

#pragma mark - NSObject

- (BOOL)isEqual:(id)other {

if (other == self) return YES;

if (!other || ![other isKindOfClass:[NNArrayDiffChange class]]) return NO;

return [self isEqualToArrayDiffChange:other];

}

- (BOOL)isEqualToArrayDiffChange:(NNArrayDiffChange *)other {

if (self.before != other.before) return NO;

if (self.after != other.after) return NO;

if (self.type != other.type) return NO;

return YES;

}

- (NSUInteger)hash {

NSUInteger prime = 31;

NSUInteger result = 1;

result = prime * result + self.before;

result = prime * result + self.after;

result = prime * result + self.type;

return result;

}

- (NSString *)description {

NSString *typeString;

if (self.type == NNDiffChangeUpdate) {

typeString = @"·>";

} else if (self.type == NNDiffChangeMove) {

typeString = @"->";

} else {

typeString = @"=>";

}

return [NSString stringWithFormat:@"%@ %@ %@", @(self.before), typeString, @(self.after)];

}

#pragma mark - NSCopying

- (id)copyWithZone:(NSZone *)zone {

return self;

}