// Copyright 2015-2020 Parity Technologies (UK) Ltd.
// This file is part of OpenEthereum.

// OpenEthereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// OpenEthereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with OpenEthereum.  If not, see <http://www.gnu.org/licenses/>.

//! Snapshot-related errors.

use std::fmt;

use types::ids::BlockId;

use ethereum_types::H256;
use ethtrie::TrieError;
use rlp::DecoderError;

/// Snapshot-related errors.
#[derive(Debug)]
pub enum Error {
    /// Invalid starting block for snapshot.
    InvalidStartingBlock(BlockId),
    /// Block not found.
    BlockNotFound(H256),
    /// Incomplete chain.
    IncompleteChain,
    /// Best block has wrong state root.
    WrongStateRoot(H256, H256),
    /// Wrong block hash.
    WrongBlockHash(u64, H256, H256),
    /// Too many blocks contained within the snapshot.
    TooManyBlocks(u64, u64),
    /// Old starting block in a pruned database.
    OldBlockPrunedDB,
    /// Missing code.
    MissingCode(Vec<H256>),
    /// Unrecognized code encoding.
    UnrecognizedCodeState(u8),
    /// Restoration aborted.
    RestorationAborted,
    /// Trie error.
    Trie(TrieError),
    /// Decoder error.
    Decoder(DecoderError),
    /// Io error.
    Io(::std::io::Error),
    /// Snapshot version is not supported.
    VersionNotSupported(u64),
    /// Max chunk size is to small to fit basic account data.
    ChunkTooSmall,
    /// Oversized chunk
    ChunkTooLarge,
    /// Snapshots not supported by the consensus engine.
    SnapshotsUnsupported,
    /// Aborted snapshot
    SnapshotAborted,
    /// Bad epoch transition.
    BadEpochProof(u64),
    /// Wrong chunk format.
    WrongChunkFormat(String),
    /// Unlinked ancient block chain
    UnlinkedAncientBlockChain,
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            Error::InvalidStartingBlock(ref id) => write!(f, "Invalid starting block: {:?}", id),
            Error::BlockNotFound(ref hash) => write!(f, "Block not found in chain: {}", hash),
            Error::IncompleteChain => write!(f, "Incomplete blockchain."),
            Error::WrongStateRoot(ref expected, ref found) => write!(
                f,
                "Final block has wrong state root. Expected {:?}, got {:?}",
                expected, found
            ),
            Error::WrongBlockHash(ref num, ref expected, ref found) => write!(
                f,
                "Block {} had wrong hash. expected {:?}, got {:?}",
                num, expected, found
            ),
            Error::TooManyBlocks(ref expected, ref found) => write!(
                f,
                "Snapshot contained too many blocks. Expected {}, got {}",
                expected, found
            ),
            Error::OldBlockPrunedDB => write!(
                f,
                "Attempted to create a snapshot at an old block while using \
				a pruned database. Please re-run with the --pruning archive flag."
            ),
            Error::MissingCode(ref missing) => write!(
                f,
                "Incomplete snapshot: {} contract codes not found.",
                missing.len()
            ),
            Error::UnrecognizedCodeState(state) => {
                write!(f, "Unrecognized code encoding ({})", state)
            }
            Error::RestorationAborted => write!(f, "Snapshot restoration aborted."),
            Error::Io(ref err) => err.fmt(f),
            Error::Decoder(ref err) => err.fmt(f),
            Error::Trie(ref err) => err.fmt(f),
            Error::VersionNotSupported(ref ver) => {
                write!(f, "Snapshot version {} is not supprted.", ver)
            }
            Error::ChunkTooSmall => write!(f, "Chunk size is too small."),
            Error::ChunkTooLarge => write!(f, "Chunk size is too large."),
            Error::SnapshotsUnsupported => write!(f, "Snapshots unsupported by consensus engine."),
            Error::SnapshotAborted => write!(f, "Snapshot was aborted."),
            Error::BadEpochProof(i) => write!(f, "Bad epoch proof for transition to epoch {}", i),
            Error::WrongChunkFormat(ref msg) => write!(f, "Wrong chunk format: {}", msg),
            Error::UnlinkedAncientBlockChain => write!(f, "Unlinked ancient blocks chain"),
        }
    }
}

impl From<::std::io::Error> for Error {
    fn from(err: ::std::io::Error) -> Self {
        Error::Io(err)
    }
}

impl From<TrieError> for Error {
    fn from(err: TrieError) -> Self {
        Error::Trie(err)
    }
}

impl From<DecoderError> for Error {
    fn from(err: DecoderError) -> Self {
        Error::Decoder(err)
    }
}

impl<E> From<Box<E>> for Error
where
    Error: From<E>,
{
    fn from(err: Box<E>) -> Self {
        Error::from(*err)
    }
}
