#import "Param.h"

@interface Param ()

@property(nonatomic, retain) id value;
@property(nonatomic) BOOL consumed;

@end

@implementation Param

+ (instancetype)withValue:(id)value {
    return [[self.class alloc] initWithValue:value];
}

- (instancetype)initWithValue:(id)value {
    self = [super init];
    self.value = value;
    return self;
}

- (id)copyWithZone:(NSZone *)zone {
    Param *param = [[self.class alloc] initWithValue:self.value];
    param.consumed = self.consumed;
    return param;
}

- (id)get {
    if (!self.value) {
        @throw [NSException exceptionWithName:@"Param get"
                                       reason:@"value does not exists"
                                     userInfo:nil];
    }
    return self.value;
}

- (id)withDefault:(id)defaultValue {
    if (self.value) {
        return self.value;
    } else if (defaultValue) {
        return defaultValue;
    }

    return nil;
}

- (void)consume {
    self.consumed = true;
}

- (BOOL)hasValue {
    return self.value && !self.consumed;
}

@end