// Copyright 2015-2020 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;
use std::sync::Arc;
use std::path::PathBuf;
use std::collections::HashSet;

use dir::default_data_path;
use dir::helpers::replace_home;
use helpers::parity_ipc_path;
use jsonrpc_core::MetaIoHandler;
use parity_runtime::Executor;
use parity_rpc::informant::{RpcStats, Middleware};
use parity_rpc::{self as rpc, Metadata, DomainsValidation};
use rpc_apis::{self, ApiSet};

pub use parity_rpc::{IpcServer, HttpServer, RequestMiddleware};
pub use parity_rpc::ws::{Server as WsServer, ws};

pub const DAPPS_DOMAIN: &'static str = "web3.site";

#[derive(Debug, Clone, PartialEq)]
pub struct HttpConfiguration {
	/// Is RPC over HTTP enabled (default is true)?
	pub enabled: bool,
	/// The IP of the network interface used (default is 127.0.0.1).
	pub interface: String,
	/// The network port (default is 8545).
	pub port: u16,
	/// The categories of RPC calls enabled.
	pub apis: ApiSet,
	/// CORS headers
	pub cors: Option<Vec<String>>,
	/// Specify a list of valid hosts we accept requests from.
	pub hosts: Option<Vec<String>>,
	/// Number of HTTP server threads to use to handle incoming requests (default is 4).
	pub server_threads: usize,
	/// Sets the maximum size of a request body in megabytes (default is 5 MiB).
	pub max_payload: usize,
	/// Use keepalive messages on the underlying socket: SO_KEEPALIVE as well as the TCP_KEEPALIVE
	/// or TCP_KEEPIDLE options depending on your platform (default is true).
	pub keep_alive: bool,
}

impl Default for HttpConfiguration {
	fn default() -> Self {
		HttpConfiguration {
			enabled: true,
			interface: "127.0.0.1".into(),
			port: 8545,
			apis: ApiSet::UnsafeContext,
			cors: Some(vec![]),
			hosts: Some(vec![]),
			server_threads: 4,
			max_payload: 5,
			keep_alive: true,
		}
	}
}

#[derive(Debug, PartialEq)]
pub struct IpcConfiguration {
	pub enabled: bool,
	pub socket_addr: String,
	pub chmod: String,
	pub apis: ApiSet,
}

impl Default for IpcConfiguration {
	fn default() -> Self {
		IpcConfiguration {
			enabled: true,
			socket_addr: if cfg!(windows) {
				r"\\.\pipe\jsonrpc.ipc".into()
			} else {
				let data_dir = ::dir::default_data_path();
				parity_ipc_path(&data_dir, "$BASE/jsonrpc.ipc", 0)
			},
			chmod: "660".into(),
			apis: ApiSet::IpcContext,
		}
	}
}

#[derive(Debug, Clone, PartialEq)]
pub struct WsConfiguration {
	pub enabled: bool,
	pub interface: String,
	pub port: u16,
	pub apis: ApiSet,
	pub max_connections: usize,
	pub origins: Option<Vec<String>>,
	pub hosts: Option<Vec<String>>,
	pub signer_path: PathBuf,
	pub support_token_api: bool,
}

impl Default for WsConfiguration {
	fn default() -> Self {
		let data_dir = default_data_path();
		WsConfiguration {
			enabled: true,
			interface: "127.0.0.1".into(),
			port: 8546,
			apis: ApiSet::UnsafeContext,
			max_connections: 100,
			origins: Some(vec!["parity://*".into(),"chrome-extension://*".into(), "moz-extension://*".into()]),
			hosts: Some(Vec::new()),
			signer_path: replace_home(&data_dir, "$BASE/signer").into(),
			support_token_api: false,
		}
	}
}

impl WsConfiguration {
	pub fn address(&self) -> Option<rpc::Host> {
		address(self.enabled, &self.interface, self.port, &self.hosts)
	}
}

fn address(enabled: bool, bind_iface: &str, bind_port: u16, hosts: &Option<Vec<String>>) -> Option<rpc::Host> {
	if !enabled {
		return None;
	}

	match *hosts {
		Some(ref hosts) if !hosts.is_empty() => Some(hosts[0].clone().into()),
		_ => Some(format!("{}:{}", bind_iface, bind_port).into()),
	}
}

pub struct Dependencies<D: rpc_apis::Dependencies> {
	pub apis: Arc<D>,
	pub executor: Executor,
	pub stats: Arc<RpcStats>,
}

pub fn new_ws<D: rpc_apis::Dependencies>(
	conf: WsConfiguration,
	deps: &Dependencies<D>,
) -> Result<Option<WsServer>, String> {
	if !conf.enabled {
		return Ok(None);
	}

	let domain = DAPPS_DOMAIN;
	let url = format!("{}:{}", conf.interface, conf.port);
	let addr = url.parse().map_err(|_| format!("Invalid WebSockets listen host/port given: {}", url))?;

	let full_handler = setup_apis(rpc_apis::ApiSet::All, deps);
	let handler = {
		let mut handler = MetaIoHandler::with_middleware((
			rpc::WsDispatcher::new(full_handler),
			Middleware::new(deps.stats.clone(), deps.apis.activity_notifier())
		));
		let apis = conf.apis.list_apis();
		deps.apis.extend_with_set(&mut handler, &apis);

		handler
	};

	let allowed_origins = into_domains(with_domain(conf.origins, domain, &None));
	let allowed_hosts = into_domains(with_domain(conf.hosts, domain, &Some(url.clone().into())));

	let signer_path;
	let path = match conf.support_token_api {
		true => {
			signer_path = ::signer::codes_path(&conf.signer_path);
			Some(signer_path.as_path())
		},
		false => None
	};
	let start_result = rpc::start_ws(
		&addr,
		handler,
		allowed_origins,
		allowed_hosts,
		conf.max_connections,
		rpc::WsExtractor::new(path.clone()),
		rpc::WsExtractor::new(path.clone()),
		rpc::WsStats::new(deps.stats.clone()),
	);

	match start_result {
		Ok(server) => Ok(Some(server)),
		Err(rpc::ws::Error::WsError(ws::Error {
			kind: ws::ErrorKind::Io(ref err), ..
		})) if err.kind() == io::ErrorKind::AddrInUse => Err(
			format!("WebSockets address {} is already in use, make sure that another instance of an Ethereum client is not running or change the address using the --ws-port and --ws-interface options.", url)
		),
		Err(e) => Err(format!("WebSockets error: {:?}", e)),
	}
}

pub fn new_http<D: rpc_apis::Dependencies>(
	id: &str,
	options: &str,
	conf: HttpConfiguration,
	deps: &Dependencies<D>,
) -> Result<Option<HttpServer>, String> {
	if !conf.enabled {
		return Ok(None);
	}

	let domain = DAPPS_DOMAIN;
	let url = format!("{}:{}", conf.interface, conf.port);
	let addr = url.parse().map_err(|_| format!("Invalid {} listen host/port given: {}", id, url))?;
	let handler = setup_apis(conf.apis, deps);

	let cors_domains = into_domains(conf.cors);
	let allowed_hosts = into_domains(with_domain(conf.hosts, domain, &Some(url.clone().into())));

	let start_result = rpc::start_http(
		&addr,
		cors_domains,
		allowed_hosts,
		handler,
		rpc::RpcExtractor,
		conf.server_threads,
		conf.max_payload,
		conf.keep_alive,
	);

	match start_result {
		Ok(server) => Ok(Some(server)),
		Err(ref err) if err.kind() == io::ErrorKind::AddrInUse => Err(
			format!("{} address {} is already in use, make sure that another instance of an Ethereum client is not running or change the address using the --{}-port and --{}-interface options.", id, url, options, options)
		),
		Err(e) => Err(format!("{} error: {:?}", id, e)),
	}
}

pub fn new_ipc<D: rpc_apis::Dependencies>(
	conf: IpcConfiguration,
	dependencies: &Dependencies<D>
) -> Result<Option<IpcServer>, String> {
	if !conf.enabled {
		return Ok(None);
	}

	let handler = setup_apis(conf.apis, dependencies);
	let path = PathBuf::from(&conf.socket_addr);
	// Make sure socket file can be created on unix-like OS.
	// Windows pipe paths are not on the FS.
	if !cfg!(windows) {
		if let Some(dir) = path.parent() {
			::std::fs::create_dir_all(&dir)
				.map_err(|err| format!("Unable to create IPC directory at {}: {}", dir.display(), err))?;
		}
	}

	// some validations ..
	let chmod = conf.chmod;
	let chmod = u16::from_str_radix(&chmod, 8)
		.map_err(|e| format!("Invalid octal value: {}", e))?;

	if chmod == 0 || chmod > 0o7777 {
		return Err("Valid octal permissions are within the range 1 to 7777".into())
	}

	match rpc::start_ipc(&conf.socket_addr, handler, rpc::RpcExtractor, chmod) {
		Ok(server) => Ok(Some(server)),
		Err(io_error) => Err(format!("IPC error: {}", io_error)),
	}
}

fn into_domains<T: From<String>>(items: Option<Vec<String>>) -> DomainsValidation<T> {
	items.map(|vals| vals.into_iter().map(T::from).collect()).into()
}

fn with_domain(items: Option<Vec<String>>, domain: &str, dapps_address: &Option<rpc::Host>) -> Option<Vec<String>> {
	fn extract_port(s: &str) -> Option<u16> {
		s.split(':').nth(1).and_then(|s| s.parse().ok())
	}

	items.map(move |items| {
		let mut items = items.into_iter().collect::<HashSet<_>>();
		{
			let mut add_hosts = |address: &Option<rpc::Host>| {
				if let Some(host) = address.clone() {
					items.insert(host.to_string());
					items.insert(host.replace("127.0.0.1", "localhost"));
					items.insert(format!("http://*.{}", domain)); //proxypac
					if let Some(port) = extract_port(&*host) {
						items.insert(format!("http://*.{}:{}", domain, port));
					}
				}
			};

			add_hosts(dapps_address);
		}
		items.into_iter().collect()
	})
}

pub fn setup_apis<D>(apis: ApiSet, deps: &Dependencies<D>) -> MetaIoHandler<Metadata, Middleware<D::Notifier>>
	where D: rpc_apis::Dependencies
{
	let mut handler = MetaIoHandler::with_middleware(
		Middleware::new(deps.stats.clone(), deps.apis.activity_notifier())
	);
	let apis = apis.list_apis();
	deps.apis.extend_with_set(&mut handler, &apis);

	handler
}

#[cfg(test)]
mod tests {
	use super::address;

	#[test]
	fn should_return_proper_address() {
		assert_eq!(address(false, "localhost", 8180, &None), None);
		assert_eq!(address(true, "localhost", 8180, &None), Some("localhost:8180".into()));
		assert_eq!(address(true, "localhost", 8180, &Some(vec!["host:443".into()])), Some("host:443".into()));
		assert_eq!(address(true, "localhost", 8180, &Some(vec!["host".into()])), Some("host".into()));
	}
}