// https://www.ietf.org/rfc/rfc1928.txt

const { currentFacet, genUuid, Bytes, Map, Observe, Skeleton } = require("@syndicate-lang/core");
const C = activate require("@syndicate-lang/server/lib/client");
const S = activate require("@syndicate-lang/driver-streams-node");
const debugFactory = require('debug');

assertion type VirtualTcpAddress(host, port);
assertion type AddressMap(from, nodeId, to);

assertion type ToNode(nodeId, assertion);
assertion type FromNode(nodeId, assertion);
assertion type RestrictedFromNode(nodeId, spec, captures);

function usage() {
  console.info('Usage: syndicate-socks-service --server WEBSOCKETURL SCOPE');
  console.info('');
  console.info('  --help, -h            Produce this message and terminate');
}

let server_url = null;
let server_scope = null;
function process_command_line(args) {
  const notUndefined = (x, w) => {
    if (x === void 0) {
      console.error('Missing '+w+' argument on command line');
      usage();
      process.exit(1);
    }
    return x;
  };
  const strArg = (w) => notUndefined(args.shift(), w);
  const numArg = (w) => Number.parseInt(notUndefined(args.shift(), w));
  while (args.length) {
    const opt = args.shift();
    switch (opt) {
      case '--server':
        server_url = strArg('server WebSocket URL');
        server_scope = strArg('server scope name');
        break;
      default:
        console.error("Unsupported command-line argument: " + opt);
        /* FALL THROUGH */
      case '--help':
      case '-h':
        usage();
        process.exit(1);
    }
  }
}

process_command_line(process.argv.slice(2));
if (!server_url || !server_scope) {
  usage();
  process.exit(1);
}
const server_addr = C.WSServer(server_url, server_scope);

const nodeId = genUuid('node');

spawn named 'test-remap' {
  during C.ServerConnected(server_addr) {
    assert C.ToServer(server_addr, AddressMap(VirtualTcpAddress("steam.fruit", 22),
                                              nodeId,
                                              S.TcpAddress('steam.eighty-twenty.org', 22)));

    assert C.ToServer(server_addr, AddressMap(VirtualTcpAddress("shell.fruit", 9999),
                                              nodeId,
                                              S.SubprocessAddress('/bin/sh', [], {})));
  }
}

spawn named 'to-node-relay' {
  const debug = debugFactory('syndicate/server:socks:to-node-relay');
  during C.ServerConnected(server_addr) {
    during C.FromServer(server_addr, ToNode(nodeId, $a)) {
      on start debug('Remote peer has asserted', a && a.toString());
      on stop debug('Remote peer has retracted', a && a.toString());
      assert a;
    }
    on message C.FromServer(server_addr, ToNode(nodeId, $a)) {
      send a;
    }
    during C.FromServer(server_addr, Observe(FromNode(nodeId, $spec))) {
      on start debug('Remote peer has asserted interest in', spec && spec.toString());
      on stop debug('Remote peer has retracted interest in', spec && spec.toString());
      currentFacet().addObserverEndpoint(() => spec, {
        add: (vs) => {
          const a = RestrictedFromNode(nodeId, spec.toString(), vs);
          debug('+', a && a.toString());
          // The "react { assert; stop on retracted ... }" pattern won't work here because of
          // the `VisibilityRestriction`s. We'll never see the "retracted" event if we "stop on
          // retracted aLocal" where aLocal = Skeleton.instantiateAssertion(spec, vs). Instead,
          // we need to use `adhocAssert` and the `del` callback.
          currentFacet().actor.adhocAssert(C.ToServer(server_addr, a));
        },
        del: (vs) => {
          const a = RestrictedFromNode(nodeId, spec.toString(), vs);
          debug('-', a && a.toString());
          currentFacet().actor.adhocRetract(C.ToServer(server_addr, a));
        },
        msg: (vs) => {
          const a = RestrictedFromNode(nodeId, spec.toString(), vs);
          debug('!', a && a.toString());
          send C.ToServer(server_addr, a);
        }
      });
    }
  }
}