use bufio;
use fmt;
use net;
use net::tcp;
use net::ip;
use io;
use os;
use fs;
use strings;
use time;
use time::date;
use time::chrono;
use unix::poll;
use drawing;
use drawing::{pos};
use packet_reader;


def PORT: u16 = 41460;

type conn = net::socket;

def CHUNKSIZE = 512;

export fn main() void = {
	// create 4 pictures. later we will have more pictures
	// but for now there are just 4, and they are at fixed positions
	const offs: [_]pos = [
		(0,0), (0,CHUNKSIZE), (CHUNKSIZE,0), (CHUNKSIZE,CHUNKSIZE),
	];

	let pictures: []drawing::picture = alloc([],len(offs));
	for (let i = 0z; i < len(offs); i +=1){
		append(pictures, drawing::picture {
			w = CHUNKSIZE,
			h = CHUNKSIZE,
			d = alloc([0...],CHUNKSIZE*CHUNKSIZE: size): *[*]u32,
			world_pos = offs[i],
		});
	};
	for (const p &.. pictures) drawing::clear_picture(p, 0xffffff);


	const listener = tcp::listen(ip::ANY_V4, PORT)!;
	loop(listener, pictures);
};

def save_interval = 5 * time::SECOND;

fn save_world(pictures: []drawing::picture) void = {
	fmt::printfln("saving world!")!;
	for (const pic &.. pictures) {
		const filename = fmt::asprintf("./c.{}.{}.ppm",pic.world_pos.0, pic.world_pos.1);
		fmt::printfln("\t-> {}",filename)!;
		defer free(filename);
		const mode = fs::mode::USER_RW | fs::mode::GROUP_RW;
		const file = os::create(filename, mode)!;
		defer {
			fmt::printfln("\t. {}",filename)!;
			io::close(file)!;
		};
		const header = fmt::asprintf("P6\n{} {}\n{}\n", pic.w, pic.h, 255);
		defer free(header);
		io::writeall(file, strings::toutf8(header))!;
		for (let i = 0z; i < pic.w * pic.h; i += 1) {
			const px = pic.d[i];
			io::writeall(file, [(px&0xff): u8, ((px>>8)&0xff): u8, ((px>>16)&0xff): u8])!;
		};
	};
		
};

fn loop(listener: net::socket, pictures: []drawing::picture) void = {
	// pollfds[0] is the listener
	// pollfds[n>0] corresponds to packet_readers[n-1]
	let pollfds: []poll::pollfd = alloc([ poll::pollfd {
		fd = listener, events = poll::event::POLLIN, revents = 0
	}]);
	let packet_readers: []packet_reader::packet_reader = [];


	let now = time::now(time::clock::MONOTONIC);
	let next = time::add(now, save_interval);

	for (true) {
		fmt::println("poll.")!;
		const timeout = time::diff(now, next);
		poll::poll(pollfds, timeout)!;

		now = time::now(time::clock::MONOTONIC);
		if (time::compare(now, next) >= 0) {
			save_world(pictures);
			next = time::add(now, save_interval);
		};

		if (0 != pollfds[0].revents & poll::event::POLLIN) {
			fmt::println("new conn")!;
			const new_conn = tcp::accept(pollfds[0].fd)!;
			fmt::println("a")!;
			append(pollfds, poll::pollfd {
				fd = new_conn,
				events = poll::event::POLLIN, revents = 0
			});
			append(packet_readers, packet_reader::new());
			fmt::printfln("there are now {},{} conns.",len(pollfds),len(packet_readers))!;
		};
		for (let i = 1z; i < len(pollfds); i += 1) {
			if (0 != pollfds[i].revents & poll::event::POLLIN) {
				match (packet_reader::read(&packet_readers[i-1], pollfds[i].fd)) {
				case void =>
					let j = 1;
					for (const packet_bytes => packet_reader::next(&packet_readers[i-1])) {
						fmt::printf("#{}:{} got {:2}",i,j,len(packet_bytes))!;
						j += 1;
						for (let byte .. packet_bytes) fmt::printf(" {:x}",byte)!;
						const op = drawing::deser_op(packet_bytes) as drawing::op_circle;
						drawing::perform(pictures, op);
						fmt::printfln("\t({:+6},{:+6})",op.0,op.1)!;
						for (let k = 1z; k < len(pollfds); k += 1) {
							if (k == i) continue;
							fmt::printfln("\t -> #{}",k)!;
							io::writeall(pollfds[k].fd, packet_bytes)!;
						};
					};
				case let err: io::error =>
					fmt::printfln("#{} error: {}",i,io::strerror(err))!;
					delete(pollfds[i]);
					delete(packet_readers[i-1]);
					i -= 1;
				case io::EOF =>
					fmt::printfln("#{} disconnect",i)!;
					delete(pollfds[i]);
					delete(packet_readers[i-1]);
					i -= 1;
				};
			};
		};
	};
};