// Copyright 2015-2019 Parity Technologies (UK) Ltd.
// This file is part of Parity Ethereum.

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

use std::{io, sync::Arc};

use parity_rpc::Metadata;
use parity_whisper::{
    message::Message,
    net::{self as whisper_net, Network as WhisperNetwork},
    rpc::{FilterManager, PoolHandle, WhisperClient},
};
use sync::{AttachedProtocol, ManageNetwork};

/// Whisper config.
#[derive(Debug, PartialEq, Eq)]
pub struct Config {
    pub enabled: bool,
    pub target_message_pool_size: usize,
}

impl Default for Config {
    fn default() -> Self {
        Config {
            enabled: false,
            target_message_pool_size: 10 * 1024 * 1024,
        }
    }
}

/// Standard pool handle.
pub struct NetPoolHandle {
    /// Pool handle.
    handle: Arc<WhisperNetwork<Arc<FilterManager>>>,
    /// Network manager.
    net: Arc<dyn ManageNetwork>,
}

impl PoolHandle for NetPoolHandle {
    fn relay(&self, message: Message) -> bool {
        let mut res = false;
        let mut message = Some(message);
        self.net
            .with_proto_context(whisper_net::PROTOCOL_ID, &mut |ctx| {
                if let Some(message) = message.take() {
                    res = self.handle.post_message(message, ctx);
                }
            });
        res
    }

    fn pool_status(&self) -> whisper_net::PoolStatus {
        self.handle.pool_status()
    }
}

/// Factory for standard whisper RPC.
pub struct RpcFactory {
    net: Arc<WhisperNetwork<Arc<FilterManager>>>,
    manager: Arc<FilterManager>,
}

impl RpcFactory {
    pub fn make_handler(
        &self,
        net: Arc<dyn ManageNetwork>,
    ) -> WhisperClient<NetPoolHandle, Metadata> {
        let handle = NetPoolHandle {
            handle: self.net.clone(),
            net: net,
        };
        WhisperClient::new(handle, self.manager.clone())
    }
}

/// Sets up whisper protocol and RPC handler.
///
/// Will target the given pool size.
#[cfg(not(feature = "ipc"))]
pub fn setup(
    target_pool_size: usize,
    protos: &mut Vec<AttachedProtocol>,
) -> io::Result<Option<RpcFactory>> {
    let manager = Arc::new(FilterManager::new()?);
    let net = Arc::new(WhisperNetwork::new(target_pool_size, manager.clone()));

    protos.push(AttachedProtocol {
        handler: net.clone() as Arc<_>,
        versions: whisper_net::SUPPORTED_VERSIONS,
        protocol_id: whisper_net::PROTOCOL_ID,
    });

    // parity-only extensions to whisper.
    protos.push(AttachedProtocol {
        handler: Arc::new(whisper_net::ParityExtensions),
        versions: whisper_net::SUPPORTED_VERSIONS,
        protocol_id: whisper_net::PARITY_PROTOCOL_ID,
    });

    let factory = RpcFactory {
        net: net,
        manager: manager,
    };

    Ok(Some(factory))
}

// TODO: make it possible to attach generic protocols in IPC.
#[cfg(feature = "ipc")]
pub fn setup(
    _target_pool_size: usize,
    _protos: &mut Vec<AttachedProtocol>,
) -> io::Result<Option<RpcFactory>> {
    Ok(None)
}