/**
 *   每天第一次启动app去签到
 */
-(BOOL)goToSign{
 
    NSDate *now = [NSDate date];
    //当前时间的时间戳
    NSTimeInterval nowStamp = [now timeIntervalSince1970];
    //当天零点的时间戳
    NSTimeInterval zeroStamp = [[[NSUserDefaults standardUserDefaults] objectForKey:@"zeroStamp"] doubleValue];
    //一天的时间戳
    NSTimeInterval oneDay = 60* 60 * 24;
    
    /**
        "hasSign"代表了是否当天是否签过到，NO代表没有签过，YES代表已经签过
     */

    if(nowStamp - zeroStamp > oneDay){
        
        zeroStamp = [self getTodayZeroStampWithDate:now];
        [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithDouble:zeroStamp] forKey:@"zeroStamp"];
        [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithBool:YES] forKey:@"hasSign"];
        return YES;
        
    }else{
        
        if ([[NSUserDefaults standardUserDefaults] objectForKey:@"hasSign"]) {
            
            return NO;
            
        } else {
            
            return YES;
            
        }
    }
}

/**
 * 获取当天零点时间戳
 */
- (double)getTodayZeroStampWithDate:(NSDate *)date{
 
    NSDateFormatter *dateFomater = [[NSDateFormatter alloc]init];
    dateFomater.dateFormat = @"yyyy年MM月dd日";
    NSString *original = [dateFomater stringFromDate:date];
    NSDate *ZeroDate = [dateFomater dateFromString:original];
    // 今天零点的时间戳
    NSTimeInterval zeroStamp = [ZeroDate timeIntervalSince1970];
    return zeroStamp;

}