#include "node.hpp"

#include "logging.hpp"

#include "gmpxx.h"

#include <iostream>

using namespace boost::asio::ip;

Node::Node(ListenSettings const& listen_settings, NodeNetworkSettings network_settings)
: io_service()
, server(io_service, listen_settings, [this](boost::asio::ip::tcp::socket&& socket){accept_handler(std::move(socket));})
, clients()
, network_settings(network_settings)
, next_node(tcp::socket(io_service))
, api(get_curve25519_implementation())
, keypair(api.create_key_pair())
, network_pub_key()
{
	auto on_connect = [this, network_settings](){
		BOOST_LOG_TRIVIAL(trace) << "is first: " << std::boolalpha << network_settings.is_first;
		if(network_settings.is_first) {
			start_initialisation();
		}
	};
	
	next_node.async_connect(network_settings.next_host, network_settings.next_port, on_connect);
}

Node::~Node() {
	api.free_key_pair(keypair);
}

void Node::run() {
	io_service.run();
}

void Node::accept_handler(boost::asio::ip::tcp::socket&& socket)
{
	clients.emplace_back(std::move(socket));

	auto it = --clients.end();
	clients.back().on_done(
		[this, it]() {
			clients.erase(it);
		}
	);
}

void Node::start_initialisation() {
	initialization init;
	init.set_public_share(keypair.pub, keypair.pub_len);
	
	BOOST_LOG_TRIVIAL(trace) << "length of keypair.pub: " << keypair.pub_len;
	
	std::string message;
	init.SerializeToString(&message);
	BOOST_LOG_TRIVIAL(trace) << "init: " << init.DebugString();
	BOOST_LOG_TRIVIAL(trace) << "size: " << message.size();
	BOOST_LOG_TRIVIAL(trace) << "raw: " << message;
	next_node.send(message);
	
	auto f = [this](std::vector<uint8_t> bytes) {
		if(network_settings.is_first) {
			BOOST_LOG_TRIVIAL(trace) << "bytes.size(): " << bytes.size();
			BOOST_LOG_TRIVIAL(trace) << "raw2: " << std::string(bytes.begin(), bytes.end());
			initialization init;
			init.ParseFromArray(bytes.data(), bytes.size());
			std::string share = init.public_share();
			
			network_pub_key = std::vector<uint8_t>(share.begin(), share.end());
			
			BOOST_LOG_TRIVIAL(trace) << "The network pub_key: " << init.DebugString();
			
			start_precomputation();
		} else {
			mpz_t shared;
			mpz_init(shared);
			mpz_import(shared, bytes.size(), -1, 1, 0, 0, bytes.data());
			
			mpz_t my_share;
			mpz_init(my_share);
			mpz_import(my_share, keypair.pub_len, -1, 1, 0, 0, keypair.pub);
			
			mpz_mul(shared, shared, my_share);
			
			mpz_t mod;
			mpz_init(mod);
			mpz_set_ui(mod, 2);
			mpz_pow_ui(mod, mod, 255);
			mpz_sub_ui(mod, mod, 19);
			
			mpz_mod(shared, shared, mod);
			
			std::vector<uint8_t> new_shared(keypair.pub_len, '\0');
			size_t size;
			mpz_export(new_shared.data(), &size, -1, 1, 0, 0, shared);
			
			initialization init;
			init.set_public_share(new_shared.data(), new_shared.size());
			
			std::string message;
			init.SerializeToString(&message);
			next_node.send(message);
			
			mpz_clear(shared);
			mpz_clear(my_share);
			mpz_clear(mod);
		}
	};
	
	for(auto&& client : clients) {
		client.receive(f);
	}
}

void Node::start_precomputation() {
	io_service.stop();
}