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// Copyright 2017 Parity Technologies (UK) Ltd.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

//! Main `ProtocolChoiceError` error.

use crate::protocol::MultistreamSelectError;
use std::error;
use std::fmt;
use std::io::Error as IoError;

/// Error that can happen when negotiating a protocol with the remote.
#[derive(Debug)]
pub enum ProtocolChoiceError {
    /// Error in the protocol.
    MultistreamSelectError(MultistreamSelectError),

    /// Received a message from the remote that makes no sense in the current context.
    UnexpectedMessage,

    /// We don't support any protocol in common with the remote.
    NoProtocolFound,
}

impl From<MultistreamSelectError> for ProtocolChoiceError {
    #[inline]
    fn from(err: MultistreamSelectError) -> ProtocolChoiceError {
        ProtocolChoiceError::MultistreamSelectError(err)
    }
}

impl From<IoError> for ProtocolChoiceError {
    #[inline]
    fn from(err: IoError) -> ProtocolChoiceError {
        MultistreamSelectError::from(err).into()
    }
}

impl error::Error for ProtocolChoiceError {
    #[inline]
    fn description(&self) -> &str {
        match *self {
            ProtocolChoiceError::MultistreamSelectError(_) => "error in the protocol",
            ProtocolChoiceError::UnexpectedMessage => {
                "received a message from the remote that makes no sense in the current context"
            }
            ProtocolChoiceError::NoProtocolFound => {
                "we don't support any protocol in common with the remote"
            }
        }
    }

    fn cause(&self) -> Option<&error::Error> {
        match *self {
            ProtocolChoiceError::MultistreamSelectError(ref err) => Some(err),
            _ => None,
        }
    }
}

impl fmt::Display for ProtocolChoiceError {
    #[inline]
    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        write!(fmt, "{}", error::Error::description(self))
    }
}