@property (nonatomic, weak) UITextField *inputField;
@property (nonatomic, strong) NSString *value;

-(void)promptEditCount {
    UIAlertController * alertController = [UIAlertController alertControllerWithTitle:@"Please enter a number" message:nil preferredStyle:UIAlertControllerStyleAlert];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.textColor = [UIColor blueColor];
        textField.clearButtonMode = UITextFieldViewModeWhileEditing;
        textField.borderStyle = UITextBorderStyleNone;
        textField.keyboardType = UIKeyboardTypeNumberPad;
        textField.inputAccessoryView = [self accessoryViewForTextField:textField];
        _inputField = textField;
    }];

    UIAlertAction *okAction = [UIAlertAction actionWithTitle:LocalizedString(@"ok") style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        NSArray * textfields = alertController.textFields;
        UITextField * field = textfields[0];
        value = field.text;
    }];
    [alertController addAction:okAction];
    UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:LocalizedString(@"cancel") style:UIAlertActionStyleCancel handler:nil];
    [alertController addAction:cancelAction];

    [self presentViewController:alertController animated:YES completion:nil];
}

-(UIView *)accessoryViewForTextField:(UITextField *)textField {
    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 44)];
    view.backgroundColor = [UIColor lightGrayColor];

    UIButton *minusButton = [UIButton buttonWithType:UIButtonTypeCustom];
    UIButton *doneButton = [UIButton buttonWithType:UIButtonTypeCustom];
    [minusButton setTitle:@"-" forState:UIControlStateNormal];
    [doneButton setTitle:LocalizedString(@"done") forState:UIControlStateNormal];
    NSInteger buttonWidth = view.frame.size.width/4;
    minusButton.frame = CGRectMake(0, 0, buttonWidth, 44);
    doneButton.frame = CGRectMake(view.frame.size.width - buttonWidth, 0, buttonWidth, 44);

    [minusButton addTarget:self action:@selector(minusTouchUpInside:) forControlEvents:UIControlEventTouchUpInside];
    [doneButton addTarget:self action:@selector(doneTouchUpInside:) forControlEvents:UIControlEventTouchUpInside];

    [view addSubview:minusButton];
    [view addSubview:doneButton];

    return view;
}

-(void)minusTouchUpInside:(id)sender {
    UITextField *valueView = (UITextField *)_inputField;
    NSString *value = valueView.text;
    if (value.length == 0) {
        valueView.text = @"-";
    } else if (value.length > 0) {
        NSString *firstCharacter = [value substringToIndex:1];
        if ([firstCharacter isEqualToString:@"-"]){
            valueView.text = [value substringFromIndex:1];
        } else {
            valueView.text = [NSString stringWithFormat:@"-%@", value];
        }
    }
}

-(void)doneTouchUpInside:(id)sender {
    [_inputField resignFirstResponder];
}