use std::io::Error as IOError;

use dhall_syntax::ParseError;

use crate::phase::binary::DecodeError;
use crate::phase::resolve::ImportError;
use crate::phase::typecheck::TypeError;

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

#[derive(Debug)]
#[non_exhaustive]
pub enum Error {
    IO(IOError),
    Parse(ParseError),
    Decode(DecodeError),
    Resolve(ImportError),
    Typecheck(TypeError),
    Deserialize(String),
}

impl std::fmt::Display for Error {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        match self {
            Error::IO(err) => write!(f, "{}", err),
            Error::Parse(err) => write!(f, "{}", err),
            Error::Decode(err) => write!(f, "{:?}", err),
            Error::Resolve(err) => write!(f, "{:?}", err),
            Error::Typecheck(err) => write!(f, "{:?}", err),
            Error::Deserialize(err) => write!(f, "{}", err),
        }
    }
}

impl std::error::Error for Error {}
impl From<IOError> for Error {
    fn from(err: IOError) -> Error {
        Error::IO(err)
    }
}
impl From<ParseError> for Error {
    fn from(err: ParseError) -> Error {
        Error::Parse(err)
    }
}
impl From<DecodeError> for Error {
    fn from(err: DecodeError) -> Error {
        Error::Decode(err)
    }
}
impl From<ImportError> for Error {
    fn from(err: ImportError) -> Error {
        Error::Resolve(err)
    }
}
impl From<TypeError> for Error {
    fn from(err: TypeError) -> Error {
        Error::Typecheck(err)
    }
}