use std::fmt::{Display, Formatter};

/**
A common type that can be used as a validation error for a field value in a form.
*/
#[derive(Debug, Copy, Clone)]
pub enum FieldError {
    Required,
    ValidIdentifier,
    PositiveNumber,
    WholeNumber,
    Currency,
    SelectOption,
    Custom(&'static str),
}

impl Display for FieldError {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        match self {
            FieldError::Required => write!(f, "Requires a value"),
            FieldError::ValidIdentifier => write!(f, "Invalid identifier"),
            FieldError::PositiveNumber => write!(f, "Requires a positive number"),
            FieldError::WholeNumber => write!(f, "Requires a whole number"),
            FieldError::Currency => write!(f, "Requires a dollar amount"),
            FieldError::SelectOption => write!(f, "Requires a valid selection"),
            FieldError::Custom(s) => write!(f, "{}", s),
        }
    }
}

impl From<&'static str> for FieldError {
    fn from(s: &'static str) -> Self {
        FieldError::Custom(s)
    }
}