use std::{fmt, io};

pub type Result<T> = std::result::Result<T, Error>;

#[derive(Copy, Clone, Eq, PartialEq, Debug)]
pub enum Error {
    /// An executable binary with that name was not found
    CannotFindBinaryPath,
    /// There was nowhere to search and the provided name wasn't an absolute path
    CannotGetCurrentDirAndPathListEmpty,
    /// Failed to canonicalize the path found
    CannotCanonicalize,
}

impl std::error::Error for Error {}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Error::CannotFindBinaryPath => write!(f, "cannot find binary path"),
            Error::CannotGetCurrentDirAndPathListEmpty => write!(
                f,
                "no path to search and provided name is not an absolute path"
            ),
            Error::CannotCanonicalize => write!(f, "cannot canonicalize path"),
        }
    }
}

#[derive(Debug)]
#[non_exhaustive]
pub enum NonFatalError {
    Io(io::Error),
    /// The Windows PATHEXT environment variable was not populated with any usable extensions,
    /// and the query did not specify a file extension. This is technically legal but probably not
    /// intentional.
    PathExtNotPopulated,
}

impl std::error::Error for NonFatalError {}

impl fmt::Display for NonFatalError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::Io(e) => write!(f, "{e}"),
            Self::PathExtNotPopulated => write!(f, "PATHEXT environment variable is not populated, and the query did not specify a file extension"),
        }
    }
}
