// Copyright 2015, 2016 Ethcore (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/>.

use std::sync::{RwLock,Arc};
use std::ops::*;
use ipc::IpcConfig;
use std::collections::HashMap;

pub type IpcModuleId = u64;

/// Blockhain database module id
pub const BLOCKCHAIN_MODULE_ID: IpcModuleId = 2000;

/// IPC service that handles module management
pub struct HypervisorService {
	check_list: RwLock<HashMap<IpcModuleId, bool>>,
}

#[derive(Ipc)]
impl HypervisorService {
	fn module_ready(&self, module_id: u64) -> bool {
		let mut check_list = self.check_list.write().unwrap();
		check_list.get_mut(&module_id).map(|mut status| *status = true);
		check_list.iter().any(|(_, status)| !status)
	}
}

impl HypervisorService {
	/// New service with the default list of modules
	pub fn new() -> Arc<HypervisorService> {
		HypervisorService::with_modules(vec![])
	}

	/// New service with list of modules that will report for being ready
	pub fn with_modules(module_ids: Vec<IpcModuleId>) -> Arc<HypervisorService> {
		let mut check_list = HashMap::new();
		for module_id in module_ids {
			check_list.insert(module_id, false);
		}
		Arc::new(HypervisorService {
			check_list: RwLock::new(check_list),
		})
	}

	/// Number of modules still being waited for check-in
	pub fn unchecked_count(&self) -> usize {
		self.check_list.read().unwrap().iter().filter(|&(_, status)| !status).count()
	}

	/// List of all modules within this service
	pub fn module_ids(&self) -> Vec<IpcModuleId> {
		self.check_list.read().unwrap().iter().map(|(module_id, _)| module_id).cloned().collect()
	}
}

impl ::ipc::IpcConfig for HypervisorService {}