use std::fmt;
use std::error::Error as StdError;
use rlp::bytes::FromBytesError;

#[derive(Debug, PartialEq, Eq)]
/// Error concerning the RLP decoder.
pub enum DecoderError {
	/// Couldn't convert given bytes to an instance of required type.
	FromBytesError(FromBytesError),
	/// Data has additional bytes at the end of the valid RLP fragment.
	RlpIsTooBig,
	/// Data has too few bytes for valid RLP.
	RlpIsTooShort,
	/// Expect an encoded list, RLP was something else.
	RlpExpectedToBeList,
	/// Expect encoded data, RLP was something else.
	RlpExpectedToBeData,
	/// Expected a different size list.
	RlpIncorrectListLen,
	/// Data length number has a prefixed zero byte, invalid for numbers.
	RlpDataLenWithZeroPrefix,
	/// List length number has a prefixed zero byte, invalid for numbers.
	RlpListLenWithZeroPrefix,
	/// Non-canonical (longer than necessary) representation used for data or list.
	RlpInvalidIndirection,
	/// Declared length is inconsistent with data specified after.
	RlpInconsistentLengthAndData
}

impl StdError for DecoderError {
	fn description(&self) -> &str {
		"builder error"
	}
}

impl fmt::Display for DecoderError {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		fmt::Debug::fmt(&self, f)
	}
}

impl From<FromBytesError> for DecoderError {
	fn from(err: FromBytesError) -> DecoderError {
		DecoderError::FromBytesError(err)
	}
}