// Copyright 2015-2018 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/>.

//! RPC Error codes and error objects

use std::fmt;

use ethcore::account_provider::{SignError as AccountError};
use ethcore::error::{Error as EthcoreError, ErrorKind, CallError};
use ethcore::client::BlockId;
use jsonrpc_core::{futures, Error, ErrorCode, Value};
use rlp::DecoderError;
use transaction::Error as TransactionError;
use ethcore_private_tx::Error as PrivateTransactionError;
use vm::Error as VMError;
use light::on_demand::error::{Error as OnDemandError, ErrorKind as OnDemandErrorKind};

mod codes {
	// NOTE [ToDr] Codes from [-32099, -32000]
	pub const UNSUPPORTED_REQUEST: i64 = -32000;
	pub const NO_WORK: i64 = -32001;
	pub const NO_AUTHOR: i64 = -32002;
	pub const NO_NEW_WORK: i64 = -32003;
	pub const NO_WORK_REQUIRED: i64 = -32004;
	pub const UNKNOWN_ERROR: i64 = -32009;
	pub const TRANSACTION_ERROR: i64 = -32010;
	pub const EXECUTION_ERROR: i64 = -32015;
	pub const EXCEPTION_ERROR: i64 = -32016;
	pub const DATABASE_ERROR: i64 = -32017;
	pub const ACCOUNT_LOCKED: i64 = -32020;
	pub const PASSWORD_INVALID: i64 = -32021;
	pub const ACCOUNT_ERROR: i64 = -32023;
	pub const PRIVATE_ERROR: i64 = -32024;
	pub const REQUEST_REJECTED: i64 = -32040;
	pub const REQUEST_REJECTED_LIMIT: i64 = -32041;
	pub const REQUEST_NOT_FOUND: i64 = -32042;
	pub const ENCRYPTION_ERROR: i64 = -32055;
	pub const ENCODING_ERROR: i64 = -32058;
	pub const FETCH_ERROR: i64 = -32060;
	pub const NO_LIGHT_PEERS: i64 = -32065;
	pub const DEPRECATED: i64 = -32070;
}

pub fn unimplemented(details: Option<String>) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: "This request is not implemented yet. Please create an issue on Github repo.".into(),
		data: details.map(Value::String),
	}
}

pub fn light_unimplemented(details: Option<String>) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: "This request is unsupported for light clients.".into(),
		data: details.map(Value::String),
	}
}

pub fn unsupported<T: Into<String>>(msg: T, details: Option<T>) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: msg.into(),
		data: details.map(Into::into).map(Value::String),
	}
}

pub fn request_not_found() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::REQUEST_NOT_FOUND),
		message: "Request not found.".into(),
		data: None,
	}
}

pub fn request_rejected() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::REQUEST_REJECTED),
		message: "Request has been rejected.".into(),
		data: None,
	}
}

pub fn request_rejected_limit() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::REQUEST_REJECTED_LIMIT),
		message: "Request has been rejected because of queue limit.".into(),
		data: None,
	}
}

pub fn request_rejected_param_limit(limit: u64, items_desc: &str) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::REQUEST_REJECTED_LIMIT),
		message: format!("Requested data size exceeds limit of {} {}.", limit, items_desc),
		data: None,
	}
}

pub fn account<T: fmt::Debug>(error: &str, details: T) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::ACCOUNT_ERROR),
		message: error.into(),
		data: Some(Value::String(format!("{:?}", details))),
	}
}

/// Internal error signifying a logic error in code.
/// Should not be used when function can just fail
/// because of invalid parameters or incomplete node state.
pub fn internal<T: fmt::Debug>(error: &str, data: T) -> Error {
	Error {
		code: ErrorCode::InternalError,
		message: format!("Internal error occurred: {}", error),
		data: Some(Value::String(format!("{:?}", data))),
	}
}

pub fn invalid_params<T: fmt::Debug>(param: &str, details: T) -> Error {
	Error {
		code: ErrorCode::InvalidParams,
		message: format!("Couldn't parse parameters: {}", param),
		data: Some(Value::String(format!("{:?}", details))),
	}
}

pub fn execution<T: fmt::Debug>(data: T) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::EXECUTION_ERROR),
		message: "Transaction execution error.".into(),
		data: Some(Value::String(format!("{:?}", data))),
	}
}

pub fn state_pruned() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: "This request is not supported because your node is running with state pruning. Run with --pruning=archive.".into(),
		data: None,
	}
}

pub fn state_corrupt() -> Error {
	internal("State corrupt", "")
}

pub fn exceptional() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::EXCEPTION_ERROR),
		message: "The execution failed due to an exception.".into(),
		data: None,
	}
}

pub fn no_work() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::NO_WORK),
		message: "Still syncing.".into(),
		data: None,
	}
}

pub fn no_new_work() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::NO_NEW_WORK),
		message: "Work has not changed.".into(),
		data: None,
	}
}

pub fn no_author() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::NO_AUTHOR),
		message: "Author not configured. Run Parity with --author to configure.".into(),
		data: None,
	}
}

pub fn no_work_required() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::NO_WORK_REQUIRED),
		message: "External work is only required for Proof of Work engines.".into(),
		data: None,
	}
}

pub fn not_enough_data() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: "The node does not have enough data to compute the given statistic.".into(),
		data: None,
	}
}

pub fn token(e: String) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNKNOWN_ERROR),
		message: "There was an error when saving your authorization tokens.".into(),
		data: Some(Value::String(e)),
	}
}

pub fn signer_disabled() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: "Trusted Signer is disabled. This API is not available.".into(),
		data: None,
	}
}

pub fn ws_disabled() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: "WebSockets Server is disabled. This API is not available.".into(),
		data: None,
	}
}

pub fn network_disabled() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: "Network is disabled or not yet up.".into(),
		data: None,
	}
}

pub fn encryption<T: fmt::Debug>(error: T) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::ENCRYPTION_ERROR),
		message: "Encryption error.".into(),
		data: Some(Value::String(format!("{:?}", error))),
	}
}

pub fn encoding<T: fmt::Debug>(error: T) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::ENCODING_ERROR),
		message: "Encoding error.".into(),
		data: Some(Value::String(format!("{:?}", error))),
	}
}

pub fn database<T: fmt::Debug>(error: T) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::DATABASE_ERROR),
		message: "Database error.".into(),
		data: Some(Value::String(format!("{:?}", error))),
	}
}

pub fn fetch<T: fmt::Debug>(error: T) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::FETCH_ERROR),
		message: "Error while fetching content.".into(),
		data: Some(Value::String(format!("{:?}", error))),
	}
}

pub fn signing(error: AccountError) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::ACCOUNT_LOCKED),
		message: "Your account is locked. Unlock the account via CLI, personal_unlockAccount or use Trusted Signer.".into(),
		data: Some(Value::String(format!("{:?}", error))),
	}
}

pub fn password(error: AccountError) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::PASSWORD_INVALID),
		message: "Account password is invalid or account does not exist.".into(),
		data: Some(Value::String(format!("{:?}", error))),
	}
}

pub fn private_message(error: PrivateTransactionError) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::PRIVATE_ERROR),
		message: "Private transactions call failed.".into(),
		data: Some(Value::String(format!("{:?}", error))),
	}
}

pub fn private_message_block_id_not_supported() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::PRIVATE_ERROR),
		message: "Pending block id not supported.".into(),
		data: None,
	}
}

pub fn transaction_message(error: &TransactionError) -> String {
	use self::TransactionError::*;

	match *error {
		AlreadyImported => "Transaction with the same hash was already imported.".into(),
		Old => "Transaction nonce is too low. Try incrementing the nonce.".into(),
		TooCheapToReplace => {
			"Transaction gas price is too low. There is another transaction with same nonce in the queue. Try increasing the gas price or incrementing the nonce.".into()
		},
		LimitReached => {
			"There are too many transactions in the queue. Your transaction was dropped due to limit. Try increasing the fee.".into()
		},
		InsufficientGas { minimal, got } => {
			format!("Transaction gas is too low. There is not enough gas to cover minimal cost of the transaction (minimal: {}, got: {}). Try increasing supplied gas.", minimal, got)
		},
		InsufficientGasPrice { minimal, got } => {
			format!("Transaction gas price is too low. It does not satisfy your node's minimal gas price (minimal: {}, got: {}). Try increasing the gas price.", minimal, got)
		},
		InsufficientBalance { balance, cost } => {
			format!("Insufficient funds. The account you tried to send transaction from does not have enough funds. Required {} and got: {}.", cost, balance)
		},
		GasLimitExceeded { limit, got } => {
			format!("Transaction cost exceeds current gas limit. Limit: {}, got: {}. Try decreasing supplied gas.", limit, got)
		},
		InvalidSignature(ref sig) => format!("Invalid signature: {}", sig),
		InvalidChainId => "Invalid chain id.".into(),
		InvalidGasLimit(_) => "Supplied gas is beyond limit.".into(),
		SenderBanned => "Sender is banned in local queue.".into(),
		RecipientBanned => "Recipient is banned in local queue.".into(),
		CodeBanned => "Code is banned in local queue.".into(),
		NotAllowed => "Transaction is not permitted.".into(),
		TooBig => "Transaction is too big, see chain specification for the limit.".into(),
		InvalidRlp(ref descr) => format!("Invalid RLP data: {}", descr),
	}
}

pub fn transaction<T: Into<EthcoreError>>(error: T) -> Error {
	let error = error.into();
	if let ErrorKind::Transaction(ref e) = *error.kind() {
		Error {
			code: ErrorCode::ServerError(codes::TRANSACTION_ERROR),
			message: transaction_message(e),
			data: None,
		}
	} else {
		Error {
			code: ErrorCode::ServerError(codes::UNKNOWN_ERROR),
			message: "Unknown error when sending transaction.".into(),
			data: Some(Value::String(format!("{:?}", error))),
		}
	}
}

pub fn decode<T: Into<EthcoreError>>(error: T) -> Error {
	let error = error.into();
	match *error.kind() {
		ErrorKind::Decoder(ref dec_err) => rlp(dec_err.clone()),
		_ => Error {
			code: ErrorCode::InternalError,
			message: "decoding error".into(),
			data: None,
		}

	}
}

pub fn rlp(error: DecoderError) -> Error {
	Error {
		code: ErrorCode::InvalidParams,
		message: "Invalid RLP.".into(),
		data: Some(Value::String(format!("{:?}", error))),
	}
}

pub fn call(error: CallError) -> Error {
	match error {
		CallError::StatePruned => state_pruned(),
		CallError::StateCorrupt => state_corrupt(),
		CallError::Exceptional => exceptional(),
		CallError::Execution(e) => execution(e),
		CallError::TransactionNotFound => internal("{}, this should not be the case with eth_call, most likely a bug.", CallError::TransactionNotFound),
	}
}

pub fn vm(error: &VMError, output: &[u8]) -> Error {
	use rustc_hex::ToHex;

	let data = match error {
		&VMError::Reverted => format!("{} 0x{}", VMError::Reverted, output.to_hex()),
		error => format!("{}", error),
	};

	Error {
		code: ErrorCode::ServerError(codes::EXECUTION_ERROR),
		message: "VM execution error.".into(),
		data: Some(Value::String(data)),
	}
}

pub fn unknown_block() -> Error {
	Error {
		code: ErrorCode::InvalidParams,
		message: "Unknown block number".into(),
		data: None,
	}
}

pub fn no_light_peers() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::NO_LIGHT_PEERS),
		message: "No light peers who can serve data".into(),
		data: None,
	}
}

pub fn deprecated<S: Into<String>, T: Into<Option<S>>>(message: T) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::DEPRECATED),
		message: "Method deprecated".into(),
		data: message.into().map(Into::into).map(Value::String),
	}
}

pub fn filter_not_found() -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST),
		message: "Filter not found".into(),
		data: None,
	}
}

pub fn filter_block_not_found(id: BlockId) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNSUPPORTED_REQUEST), // Specified in EIP-234.
		message: "One of the blocks specified in filter (fromBlock, toBlock or blockHash) cannot be found".into(),
		data: Some(Value::String(match id {
			BlockId::Hash(hash) => format!("0x{:x}", hash),
			BlockId::Number(number) => format!("0x{:x}", number),
			BlockId::Earliest => "earliest".to_string(),
			BlockId::Latest => "latest".to_string(),
		})),
	}
}

pub fn on_demand_error(err: OnDemandError) -> Error {
	match err {
		OnDemandError(OnDemandErrorKind::ChannelCanceled(e), _) => on_demand_cancel(e),
		OnDemandError(OnDemandErrorKind::MaxAttemptReach(_), _) => max_attempts_reached(&err),
		OnDemandError(OnDemandErrorKind::TimeoutOnNewPeers(_,_), _) => timeout_new_peer(&err),
		_ => on_demand_others(&err),
	}
}

// on-demand sender cancelled.
pub fn on_demand_cancel(_cancel: futures::sync::oneshot::Canceled) -> Error {
	internal("on-demand sender cancelled", "")
}

pub fn max_attempts_reached(err: &OnDemandError) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::REQUEST_NOT_FOUND),
		message: err.to_string(),
		data: None,
	}
}

pub fn timeout_new_peer(err: &OnDemandError) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::NO_LIGHT_PEERS),
		message: err.to_string(),
		data: None,
	}
}

pub fn on_demand_others(err: &OnDemandError) -> Error {
	Error {
		code: ErrorCode::ServerError(codes::UNKNOWN_ERROR),
		message: err.to_string(),
		data: None,
	}
}