beats-server/main.cpp

#include <map>
#include <string>

#include <lib/libwebsockets.h>
#include <json_spirit/json_spirit.h>
#include "websockets.h"

namespace js = json_spirit;

js::Object get_object(std::string const & in){
	js::Value value;
	js::read(in, value);
	return value.getObject();
}

int uid = 0;
struct User {
	unsigned int index{0};
	std::string name{"Guest"};

	int width{0};
	int height{0};

	static User from_json(const js::Object& obj){
		User ret;
		#define in(x, f) ret.x = obj.at(#x).f()
		in(name, getString);
		in(width, getInt);
		in(height, getInt);
		#undef in
		return ret;
	}

	js::Object to_json() const {
		js::Object obj;
		#define out(x) obj[#x] = x
		out(name);
		out(width);
		out(height);
		#undef out
		return obj;
	}
};

// unfortunately libwebsockets own the user thingy
std::map<unsigned int, User*> people_online;


websockets::TestProtocol<User> default_protocol{
	// connection established
	[](User& user){
		user.name = "Unknown guest";
		user.index = uid++;
		people_online[user.index] = &user;
	},
	// connection closed
	[](User& user){
		people_online.erase(user.index);
	},
	// write (will always come after receive)
	[](User& user) -> std::string{
		std::string string_to_send = "Other People:";
		for(auto x : people_online) if(x.second != &user) string_to_send += " " + x.second->name;
		return string_to_send;
	},
	// receive
	[](User& user, std::string in){
		try{
			user = User::from_json(get_object(in));
		} catch(std::exception& e) {
			throw websockets::runtime_error(e.what());
		}
	}
};

struct Empty{
	int x;
};

websockets::TestProtocol<Empty> observer_protocol{
	// connection established
	[](Empty& user){},
	// connection closed
	[](Empty& user){},
	// write (will always come after receive)
	[](Empty& user) -> std::string{
		js::Array array;
		for(auto x : people_online){
			array.push_back(x.second->to_json());
		}
		js::Value value(array);
		std::cout << "OUTPUT JSON: " << write(value, js::remove_trailing_zeros) << std::endl;
		return write(value);
	},
	// receive
	[](Empty& user, std::string in){
		std::cout << "INPUT: " << in << std::endl;
	}
};

static libwebsocket_protocols protocols[] = {
	WSstandard_protocol("default", default_protocol),
	WSstandard_protocol("observer", observer_protocol),
	{ NULL, NULL, 0 } // end of list
};

int main(int argc, char **argv){
	return websockets::default_main(argc, argv, protocols);
}