// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0

// This program 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.

// This program 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 this program. If not, see <https://www.gnu.org/licenses/>.

//! Error helpers for `chainHead` RPC module.

use jsonrpsee::types::error::ErrorObject;

/// ChainHead RPC errors.
#[derive(Debug, thiserror::Error)]
pub enum Error {
	/// Maximum number of chainHead_follow has been reached.
	#[error("Maximum number of chainHead_follow has been reached")]
	ReachedLimits,
	/// The provided block hash is invalid.
	#[error("Invalid block hash")]
	InvalidBlock,
	/// The follow subscription was started with `withRuntime` set to `false`.
	#[error("The `chainHead_follow` subscription was started with `withRuntime` set to `false`")]
	InvalidRuntimeCall(String),
	/// Wait-for-continue event not generated.
	#[error("Wait for continue event was not generated for the subscription")]
	InvalidContinue,
	/// Received duplicate hashes for the `chainHead_unpin` method.
	#[error("Received duplicate hashes for the `chainHead_unpin` method")]
	InvalidDuplicateHashes,
	/// Invalid parameter provided to the RPC method.
	#[error("Invalid parameter: {0}")]
	InvalidParam(String),
	/// Internal error.
	#[error("Internal error: {0}")]
	InternalError(String),
}

/// Errors for `chainHead` RPC module, as defined in
/// <https://github.com/paritytech/json-rpc-interface-spec>.
pub mod rpc_spec_v2 {
	/// Maximum number of chainHead_follow has been reached.
	pub const REACHED_LIMITS: i32 = -32800;
	/// The provided block hash is invalid.
	pub const INVALID_BLOCK_ERROR: i32 = -32801;
	/// The follow subscription was started with `withRuntime` set to `false`.
	pub const INVALID_RUNTIME_CALL: i32 = -32802;
	/// Wait-for-continue event not generated.
	pub const INVALID_CONTINUE: i32 = -32803;
	/// Received duplicate hashes for the `chainHead_unpin` method.
	pub const INVALID_DUPLICATE_HASHES: i32 = -32804;
}

/// General purpose errors, as defined in
/// <https://www.jsonrpc.org/specification#error_object>.
pub mod json_rpc_spec {
	/// Invalid parameter error.
	pub const INVALID_PARAM_ERROR: i32 = -32602;
	/// Internal error.
	pub const INTERNAL_ERROR: i32 = -32603;
}

impl From<Error> for ErrorObject<'static> {
	fn from(e: Error) -> Self {
		let msg = e.to_string();

		match e {
			Error::ReachedLimits =>
				ErrorObject::owned(rpc_spec_v2::REACHED_LIMITS, msg, None::<()>),
			Error::InvalidBlock =>
				ErrorObject::owned(rpc_spec_v2::INVALID_BLOCK_ERROR, msg, None::<()>),
			Error::InvalidRuntimeCall(_) =>
				ErrorObject::owned(rpc_spec_v2::INVALID_RUNTIME_CALL, msg, None::<()>),
			Error::InvalidContinue =>
				ErrorObject::owned(rpc_spec_v2::INVALID_CONTINUE, msg, None::<()>),
			Error::InvalidDuplicateHashes =>
				ErrorObject::owned(rpc_spec_v2::INVALID_DUPLICATE_HASHES, msg, None::<()>),
			Error::InvalidParam(_) =>
				ErrorObject::owned(json_rpc_spec::INVALID_PARAM_ERROR, msg, None::<()>),
			Error::InternalError(_) =>
				ErrorObject::owned(json_rpc_spec::INTERNAL_ERROR, msg, None::<()>),
		}
	}
}
