// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.

// Parity 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.

// Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.

//! General error types for use in ethcore.

use std::fmt;
use kvdb;
use ethereum_types::{H256, U256, Address, Bloom};
use util_error::UtilError;
use snappy::InvalidInput;
use unexpected::{Mismatch, OutOfBounds};
use trie::TrieError;
use io::*;
use header::BlockNumber;
use client::Error as ClientError;
use snapshot::Error as SnapshotError;
use engines::EngineError;
use ethkey::Error as EthkeyError;
use account_provider::SignError as AccountsError;
use transaction::Error as TransactionError;

pub use executed::{ExecutionError, CallError};

#[derive(Debug, PartialEq, Clone, Copy, Eq)]
/// Errors concerning block processing.
pub enum BlockError {
	/// Block has too many uncles.
	TooManyUncles(OutOfBounds<usize>),
	/// Extra data is of an invalid length.
	ExtraDataOutOfBounds(OutOfBounds<usize>),
	/// Seal is incorrect format.
	InvalidSealArity(Mismatch<usize>),
	/// Block has too much gas used.
	TooMuchGasUsed(OutOfBounds<U256>),
	/// Uncles hash in header is invalid.
	InvalidUnclesHash(Mismatch<H256>),
	/// An uncle is from a generation too old.
	UncleTooOld(OutOfBounds<BlockNumber>),
	/// An uncle is from the same generation as the block.
	UncleIsBrother(OutOfBounds<BlockNumber>),
	/// An uncle is already in the chain.
	UncleInChain(H256),
	/// An uncle is included twice.
	DuplicateUncle(H256),
	/// An uncle has a parent not in the chain.
	UncleParentNotInChain(H256),
	/// State root header field is invalid.
	InvalidStateRoot(Mismatch<H256>),
	/// Gas used header field is invalid.
	InvalidGasUsed(Mismatch<U256>),
	/// Transactions root header field is invalid.
	InvalidTransactionsRoot(Mismatch<H256>),
	/// Difficulty is out of range; this can be used as an looser error prior to getting a definitive
	/// value for difficulty. This error needs only provide bounds of which it is out.
	DifficultyOutOfBounds(OutOfBounds<U256>),
	/// Difficulty header field is invalid; this is a strong error used after getting a definitive
	/// value for difficulty (which is provided).
	InvalidDifficulty(Mismatch<U256>),
	/// Seal element of type H256 (max_hash for Ethash, but could be something else for
	/// other seal engines) is out of bounds.
	MismatchedH256SealElement(Mismatch<H256>),
	/// Proof-of-work aspect of seal, which we assume is a 256-bit value, is invalid.
	InvalidProofOfWork(OutOfBounds<U256>),
	/// Some low-level aspect of the seal is incorrect.
	InvalidSeal,
	/// Gas limit header field is invalid.
	InvalidGasLimit(OutOfBounds<U256>),
	/// Receipts trie root header field is invalid.
	InvalidReceiptsRoot(Mismatch<H256>),
	/// Timestamp header field is invalid.
	InvalidTimestamp(OutOfBounds<u64>),
	/// Timestamp header field is too far in future.
	TemporarilyInvalid(OutOfBounds<u64>),
	/// Log bloom header field is invalid.
	InvalidLogBloom(Mismatch<Bloom>),
	/// Parent hash field of header is invalid; this is an invalid error indicating a logic flaw in the codebase.
	/// TODO: remove and favour an assert!/panic!.
	InvalidParentHash(Mismatch<H256>),
	/// Number field of header is invalid.
	InvalidNumber(Mismatch<BlockNumber>),
	/// Block number isn't sensible.
	RidiculousNumber(OutOfBounds<BlockNumber>),
	/// Too many transactions from a particular address.
	TooManyTransactions(Address),
	/// Parent given is unknown.
	UnknownParent(H256),
	/// Uncle parent given is unknown.
	UnknownUncleParent(H256),
	/// No transition to epoch number.
	UnknownEpochTransition(u64),
}

impl fmt::Display for BlockError {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		use self::BlockError::*;

		let msg = match *self {
			TooManyUncles(ref oob) => format!("Block has too many uncles. {}", oob),
			ExtraDataOutOfBounds(ref oob) => format!("Extra block data too long. {}", oob),
			InvalidSealArity(ref mis) => format!("Block seal in incorrect format: {}", mis),
			TooMuchGasUsed(ref oob) => format!("Block has too much gas used. {}", oob),
			InvalidUnclesHash(ref mis) => format!("Block has invalid uncles hash: {}", mis),
			UncleTooOld(ref oob) => format!("Uncle block is too old. {}", oob),
			UncleIsBrother(ref oob) => format!("Uncle from same generation as block. {}", oob),
			UncleInChain(ref hash) => format!("Uncle {} already in chain", hash),
			DuplicateUncle(ref hash) => format!("Uncle {} already in the header", hash),
			UncleParentNotInChain(ref hash) => format!("Uncle {} has a parent not in the chain", hash),
			InvalidStateRoot(ref mis) => format!("Invalid state root in header: {}", mis),
			InvalidGasUsed(ref mis) => format!("Invalid gas used in header: {}", mis),
			InvalidTransactionsRoot(ref mis) => format!("Invalid transactions root in header: {}", mis),
			DifficultyOutOfBounds(ref oob) => format!("Invalid block difficulty: {}", oob),
			InvalidDifficulty(ref mis) => format!("Invalid block difficulty: {}", mis),
			MismatchedH256SealElement(ref mis) => format!("Seal element out of bounds: {}", mis),
			InvalidProofOfWork(ref oob) => format!("Block has invalid PoW: {}", oob),
			InvalidSeal => "Block has invalid seal.".into(),
			InvalidGasLimit(ref oob) => format!("Invalid gas limit: {}", oob),
			InvalidReceiptsRoot(ref mis) => format!("Invalid receipts trie root in header: {}", mis),
			InvalidTimestamp(ref oob) => format!("Invalid timestamp in header: {}", oob),
			TemporarilyInvalid(ref oob) => format!("Future timestamp in header: {}", oob),
			InvalidLogBloom(ref oob) => format!("Invalid log bloom in header: {}", oob),
			InvalidParentHash(ref mis) => format!("Invalid parent hash: {}", mis),
			InvalidNumber(ref mis) => format!("Invalid number in header: {}", mis),
			RidiculousNumber(ref oob) => format!("Implausible block number. {}", oob),
			UnknownParent(ref hash) => format!("Unknown parent: {}", hash),
			UnknownUncleParent(ref hash) => format!("Unknown uncle parent: {}", hash),
			UnknownEpochTransition(ref num) => format!("Unknown transition to epoch number: {}", num),
			TooManyTransactions(ref address) => format!("Too many transactions from: {}", address),
		};

		f.write_fmt(format_args!("Block error ({})", msg))
	}
}

#[derive(Debug, Clone, Copy, PartialEq)]
/// Import to the block queue result
pub enum ImportError {
	/// Already in the block chain.
	AlreadyInChain,
	/// Already in the block queue.
	AlreadyQueued,
	/// Already marked as bad from a previous import (could mean parent is bad).
	KnownBad,
}

impl fmt::Display for ImportError {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		let msg = match *self {
			ImportError::AlreadyInChain => "block already in chain",
			ImportError::AlreadyQueued => "block already in the block queue",
			ImportError::KnownBad => "block known to be bad",
		};

		f.write_fmt(format_args!("Block import error ({})", msg))
	}
}
/// Error dedicated to import block function
#[derive(Debug)]
pub enum BlockImportError {
	/// Import error
	Import(ImportError),
	/// Block error
	Block(BlockError),
	/// Other error
	Other(String),
}

impl From<Error> for BlockImportError {
	fn from(e: Error) -> Self {
		match e {
			Error::Block(block_error) => BlockImportError::Block(block_error),
			Error::Import(import_error) => BlockImportError::Import(import_error),
			_ => BlockImportError::Other(format!("other block import error: {:?}", e)),
		}
	}
}

/// Api-level error for transaction import
#[derive(Debug, Clone)]
pub enum TransactionImportError {
	/// Transaction error
	Transaction(TransactionError),
	/// Other error
	Other(String),
}

impl From<Error> for TransactionImportError {
	fn from(e: Error) -> Self {
		match e {
			Error::Transaction(transaction_error) => TransactionImportError::Transaction(transaction_error),
			_ => TransactionImportError::Other(format!("other block import error: {:?}", e)),
		}
	}
}

#[derive(Debug)]
/// General error type which should be capable of representing all errors in ethcore.
pub enum Error {
	/// Client configuration error.
	Client(ClientError),
	/// Database error.
	Database(kvdb::Error),
	/// Error concerning a utility.
	Util(UtilError),
	/// Error concerning block processing.
	Block(BlockError),
	/// Unknown engine given.
	UnknownEngineName(String),
	/// Error concerning EVM code execution.
	Execution(ExecutionError),
	/// Error concerning transaction processing.
	Transaction(TransactionError),
	/// Error concerning block import.
	Import(ImportError),
	/// PoW hash is invalid or out of date.
	PowHashInvalid,
	/// The value of the nonce or mishash is invalid.
	PowInvalid,
	/// Error concerning TrieDBs
	Trie(TrieError),
	/// Io crate error.
	Io(IoError),
	/// Standard io error.
	StdIo(::std::io::Error),
	/// Snappy error.
	Snappy(InvalidInput),
	/// Snapshot error.
	Snapshot(SnapshotError),
	/// Consensus vote error.
	Engine(EngineError),
	/// Ethkey error.
	Ethkey(EthkeyError),
	/// Account Provider error.
	AccountProvider(AccountsError),
}

impl fmt::Display for Error {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
		match *self {
			Error::Client(ref err) => err.fmt(f),
			Error::Database(ref err) => err.fmt(f),
			Error::Util(ref err) => err.fmt(f),
			Error::Io(ref err) => err.fmt(f),
			Error::Block(ref err) => err.fmt(f),
			Error::Execution(ref err) => err.fmt(f),
			Error::Transaction(ref err) => err.fmt(f),
			Error::Import(ref err) => err.fmt(f),
			Error::UnknownEngineName(ref name) =>
				f.write_fmt(format_args!("Unknown engine name ({})", name)),
			Error::PowHashInvalid => f.write_str("Invalid or out of date PoW hash."),
			Error::PowInvalid => f.write_str("Invalid nonce or mishash"),
			Error::Trie(ref err) => err.fmt(f),
			Error::StdIo(ref err) => err.fmt(f),
			Error::Snappy(ref err) => err.fmt(f),
			Error::Snapshot(ref err) => err.fmt(f),
			Error::Engine(ref err) => err.fmt(f),
			Error::Ethkey(ref err) => err.fmt(f),
			Error::AccountProvider(ref err) => err.fmt(f),
		}
	}
}

/// Result of import block operation.
pub type ImportResult = Result<H256, Error>;

impl From<ClientError> for Error {
	fn from(err: ClientError) -> Error {
		match err {
			ClientError::Trie(err) => Error::Trie(err),
			_ => Error::Client(err)
		}
	}
}

impl From<kvdb::Error> for Error {
	fn from(err: kvdb::Error) -> Error {
		Error::Database(err)
	}
}

impl From<TransactionError> for Error {
	fn from(err: TransactionError) -> Error {
		Error::Transaction(err)
	}
}

impl From<ImportError> for Error {
	fn from(err: ImportError) -> Error {
		Error::Import(err)
	}
}

impl From<BlockError> for Error {
	fn from(err: BlockError) -> Error {
		Error::Block(err)
	}
}

impl From<ExecutionError> for Error {
	fn from(err: ExecutionError) -> Error {
		Error::Execution(err)
	}
}

impl From<::rlp::DecoderError> for Error {
	fn from(err: ::rlp::DecoderError) -> Error {
		Error::Util(UtilError::from(err))
	}
}

impl From<UtilError> for Error {
	fn from(err: UtilError) -> Error {
		Error::Util(err)
	}
}

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

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

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

impl From<BlockImportError> for Error {
	fn from(err: BlockImportError) -> Error {
		match err {
			BlockImportError::Block(e) => Error::Block(e),
			BlockImportError::Import(e) => Error::Import(e),
			BlockImportError::Other(s) => Error::Util(UtilError::from(s)),
		}
	}
}

impl From<::snappy::InvalidInput> for Error {
	fn from(err: ::snappy::InvalidInput) -> Error {
		Error::Snappy(err)
	}
}

impl From<SnapshotError> for Error {
	fn from(err: SnapshotError) -> Error {
		match err {
			SnapshotError::Io(err) => Error::StdIo(err),
			SnapshotError::Trie(err) => Error::Trie(err),
			SnapshotError::Decoder(err) => err.into(),
			other => Error::Snapshot(other),
		}
	}
}

impl From<EngineError> for Error {
	fn from(err: EngineError) -> Error {
		Error::Engine(err)
	}
}

impl From<EthkeyError> for Error {
	fn from(err: EthkeyError) -> Error {
		Error::Ethkey(err)
	}
}

impl From<AccountsError> for Error {
	fn from(err: AccountsError) -> Error {
		Error::AccountProvider(err)
	}
}

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