// 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;
use std::ops::*;
use std::convert::*;
use ipc::IpcConfig;
use util::bytes::{FromRawBytes, BytesConvertable, FromBytesError};

pub struct Service {
	pub commits: RwLock<usize>,
	pub rollbacks: RwLock<usize>,
}

pub struct CustomData {
	pub a: usize,
	pub b: usize,
}

impl FromRawBytes for CustomData {
	fn from_bytes(bytes: &[u8]) -> Result<CustomData, FromBytesError> {
		Ok(CustomData {
			a: bytes[0] as usize * 256 + bytes[1] as usize,
			b: bytes[2] as usize * 256 + bytes[3] as usize
		})
	}
}

impl BytesConvertable for CustomData {
	fn bytes(&self) -> &[u8] {
		let ip: *const CustomData = self;
    	let ptr: *const u8 = ip as *const _;
		unsafe {
    		::std::slice::from_raw_parts(
        		ptr,
        		::std::mem::size_of::<CustomData>()
    		)
		}
	}
}

#[derive(Ipc)]
impl Service {
	fn commit(&self, f: u32) -> u32 {
		let mut lock = self.commits.write().unwrap();
		*lock = *lock + f as usize;
		f
	}
	pub fn rollback(&self, a: Option<u32>, b: u32) -> i32 {
		let a_0 = a.unwrap_or_else(|| 0);
		let mut lock = self.rollbacks.write().unwrap();
		*lock = *lock + a_0 as usize - b as usize;
		(a_0 - b) as i32
	}
	pub fn push_custom(&self, data: CustomData) -> bool {
		let mut clock = self.commits.write().unwrap();
		let mut rlock = self.commits.write().unwrap();

		*clock = data.a;
		*rlock = data.b;

		true
	}
}

impl Service {
	pub fn new() -> Service {
		Service {
			commits: RwLock::new(0usize),
			rollbacks: RwLock::new(0usize),
		}
	}
}

impl ::ipc::IpcConfig for Service {}