use fmt;
use net;
use net::tcp;
use net::ip;
use io;
use os;
use unix::poll;
use bufio;

def PORT: u16 = 41460;

type conn = net::socket;

type packet = []u8;
def PCKSZ: size = 4;

type packet_reader = struct {
	buf: [256]u8,
	good: []u8,
};

fn packet_reader_new() packet_reader = {
	let pr = packet_reader {
		buf = [0...],
		...
	};
	pr.good = pr.buf[0..0];
	return pr;

};

// call when input is ready. could block otherwise
fn packet_reader_read(pr: *packet_reader, sock: net::socket) (void | io::error | io::EOF) = {
	const remaining_amt = len(pr.good);
	const read_pos = if (remaining_amt > 0) {
		// still some unconsumed content in the buffer
		// move unconsumed stuff to start of buffer
		fmt::printfln("moving {} remaining bytes",remaining_amt)!;
		pr.buf[0..remaining_amt] = pr.good;
		yield remaining_amt;
	} else 0z;
	const nread = match(io::read(sock, pr.buf[read_pos..])?) {
		case io::EOF => return io::EOF;
		case let n: size => yield n;
	};
	fmt::printfln("read {} bytes",nread)!;
	const total_amt = read_pos + nread;
	pr.good = pr.buf[0..total_amt];
	fmt::printfln("now {} bytes in buffer",total_amt)!;
};


fn packet_reader_next(pr: *packet_reader) (packet | done) = {
	// either parse a full packet out of the front of good,
	// move good along that many bytes,
	// and return the packet,
	// or, ascertain there is no full packet, and return done
	if (len(pr.good) < PCKSZ) return done;
	const packet_bytes = pr.good[..PCKSZ];
	pr.good = pr.good[PCKSZ..];
	return packet_bytes;
};

export fn main() void = {
	const listener = tcp::listen(ip::ANY_V4, PORT)!;
	const conn = tcp::accept(listener)!;

	const pr = packet_reader_new();
	for :mainloop (true) {
		if (packet_reader_read(&pr, conn)! is io::EOF)
			fmt::fatal("disconnected");
		let i = 0;
		for (const packet => packet_reader_next(&pr)) {
			fmt::printf("#{} got {}:",i,len(packet))!;
			i+=1;
			for (let byte .. packet) fmt::printf(" {:x}",byte)!;
			fmt::println("")!;
		};
	};

};


// fn loop(listener: net::socket) void = {
// 	const buf: [256]u8 = [0...];
// 	let pollfds: []poll::pollfd = alloc([ poll::pollfd {
// 		fd = listener, events = poll::event::POLLIN, revents = 0
// 	}]);

// 	for (true) {
// 		poll::poll(pollfds, poll::INDEF)!;
// 		if (0 != pollfds[0].revents & poll::event::POLLIN) {
// 			fmt::println("new conn")!;
// 			append(pollfds, poll::pollfd {
// 				fd = tcp::accept(pollfds[0].fd)!,
// 				events = poll::event::POLLIN, revents = 0
// 			});
// 		};
// 		for (let i = 1z; i < len(pollfds); i += 1) {
// 			if (0 != pollfds[i].revents & poll::event::POLLIN) {
// 				match (io::read(pollfds[i].fd, buf)!) {
// 				case io::EOF =>
// 					fmt::println("disconnect", i)!;
// 					delete(pollfds[i]);
// 					i -= 1;
// 				case let n: size =>
// 					io::write(os::stdout_file, buf[..n])!;
// 					for (let j = 1z; j < len(pollfds); j += 1) {
// 						if (i != j) {
// 							io::writeall(pollfds[j].fd, buf[..n])!;
// 						};
// 					};
// 				};
// 			};

// 		};
// 	};
// };