use std::{
    error,
    fmt,
    io,
};

#[derive(Debug)]
pub enum Error
{
    Unknown,
    IO(io::Error),
    HTTP(reqwest::Error),
    HTTPStatus(reqwest::StatusCode),
}

impl error::Error for Error
{
    fn source(&self) -> Option<&(dyn error::Error + 'static)>
    {
	match &self {
	    Error::IO(io) => Some(io),
	    _ => None
	}
    }
}

impl fmt::Display for Error
{
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
    {
	match self {
	    Error::IO(io) => write!(f, "io: {}", io),
	    Error::HTTP(http) => write!(f, "http internal error: {}", http),
	    Error::HTTPStatus(status) => write!(f, "response returned status code {}", status),
	    _ => write!(f, "unknown error"),
	}
    }
}

impl From<io::Error> for Error
{
    fn from(er: io::Error) -> Self
    {
	Self::IO(er)
    }
}

impl From<reqwest::Error> for Error
{
    fn from(er: reqwest::Error) -> Self
    {
	match er.status() {
	    Some(status) => Self::HTTPStatus(status),
	    None => Self::HTTP(er),
	}
    }
}