use std::fmt::Display;

use hyper::StatusCode;

/// Encapsulates a status code and an error message.
///
/// All client errors in [`crate::request`] implement [`Into<Error>`].
#[derive(Debug)]
pub struct Error {
    pub code: StatusCode,
    pub message: String,
}

impl Display for Error {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "error: {}", self.message)
    }
}

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

impl Error {
    /// Returns an HTTP response builder with the status code set to `self.code`.
    pub fn response_builder(&self) -> hyper::http::response::Builder {
        hyper::Response::builder().status(self.code)
    }

    // some conventient constructors for common errors

    pub fn bad_request(message: String) -> Self {
        Error{code: StatusCode::BAD_REQUEST, message}
    }
    pub fn not_found(message: String) -> Self {
        Error{code: StatusCode::NOT_FOUND, message}
    }
    pub fn unauthorized(message: String) -> Self {
        Error{code: StatusCode::UNAUTHORIZED, message}
    }
    pub fn internal(message: String) -> Self {
        Error{code: StatusCode::INTERNAL_SERVER_ERROR, message}
    }
    pub fn method_not_allowed(message: String) -> Self {
        Error{code: StatusCode::METHOD_NOT_ALLOWED, message}
    }
}

macro_rules! impl_into_http_error {
    ($type:ident, $status:expr) => {
       impl From<$type> for crate::error::Error {
            fn from(err: $type) -> Self {
                Self{code: $status, message: format!("{}", err)}
            }
       }
    };
}