!7

concept Domain {

  S domain;

  S moduleLibID;

  S proxyDestination;

  S proxyCookieChecker; // a module lib ID

  bool mustBeEnabled;

  toString { ret super.toString() + " " + domain; }

}

cm Eleu3 > DynEleu {

  transient CRUD<Domain> domainCRUD;

  switchable bool verbose;

  switchable bool debugNanoHTTPD;

  switchable S sameSite;

  start {

    NanoHTTPD_debug = debugNanoHTTPD;

    useDBOf(#1029618); // NOT WORKING?!

    dbIndexingCI(Domain, 'domain);

    uniqCI Domain(domain := "<default>");

    domainCRUD = new CRUD(Domain);

    dm_registerAs eleuWithCRUD();

  }

  visualize {

    var c = jtabs(

     "Main", super.visualize(),

      "Domains" := domainCRUD.visualize());

    tablePopupMenu(domainCRUD.table(), voidfunc(JPopupMenu menu, int row) {

      Domain d = domainCRUD.selected(), ret if null;

      if (nempty(d.moduleLibID))

        addMenuItem(menu, "Load module", rThreadEnter { dm_makeOrShow(d.moduleLibID) });

    });

    ret c;

  }

  @Override 

  S moduleForDomain(S domain) {

    domain = dropAfterColon(domain); // drop port number

    for (Domain d : domainsInMatchingOrder()) {

      if (matchingDomain(d, domain)) {

        S mod = findMod(d);

        if (verbose) print("Domain matched: " + domain + " / " + d.domain + " => " + mod); 

        try answer mod;

      } else

        if (verbose) print("Domain not matched: " + domain + " / " + d.domain); 

    }

    ret findMod(defaultDomain());

  }

  Domain defaultDomain() {

    ret conceptWhereCI Domain(domain := "<default>");

  }

  S findMod(Domain d) {

    if (d == null || empty(d.moduleLibID)) null;

    ret d.mustBeEnabled

      ? dm_findModuleWithParams(d.moduleLibID, enabled := true)

      : dm_findModule(d.moduleLibID);

  }

  ServeHttp_CookieHandler makeCookieHandler() {

    ServeHttp_CookieHandler cookieHandler = super.makeCookieHandler();

    cookieHandler.metaParams = appendPrefixIfNempty("SameSite=", sameSite);

    ret cookieHandler;

  }

  void onWebServersStarted :: after {

    forEach(webServers(), ws -> {

      print("Augmenting web server: " + ws);

      ws.collectHeaderLines = true;

      // session is an instance of NanoHTTPD.IHTTPSession

      ws.specialHandling = session -> ctex {

        temp enter();

        S domain = dropPortFromHost(mapGet(session.getHeaders(), "host"));

        Domain d = first(domainsInMatchingOrder(), 

          _d -> matchingDomain(_d, domain));

        printVars(+domain, +d);

        if (d == null || empty(d.proxyDestination)) false;

        print("Handling proxy request to " + d.proxyDestination);

        HostAndPort hap = new(d.proxyDestination);

        if (nempty(d.proxyCookieChecker)) {

          S cookieChecker = dm_findModule(d.proxyCookieChecker);

          if (empty(cookieChecker))

            fail(print("Cookie checker " + d.proxyCookieChecker + " not found, aborting request"));

          NanoHTTPD.CookieHandler cookies = session.getCookies();

          if (!isTrue(dm_call(cookieChecker, "checkCookie", cookies.read("cookie"), domain)))

            fail(print("Cookie checker disapproves"));

        }

        S headers = windowsLineBreaks(lines(concatLists(

          ll(session.getMethod() + " " + session.getFullURI() + " " + session.getProtocolVersion()),

          session.getHeaderLines()

        )));

        new StandaloneHttpProxy proxy;

        proxy.rewriteHostHeader = false;

        proxy.forwardServerAndPort = req -> hap;

        proxy.takeOverIncomingSocket(session.getSocket(),

          session.getInputStream(),

          session.getOutputStream(),

          toUtf8(printQuoted("HEADERS: ", headers))

        );

        true;

      };

    });

  } // onWebServersStarted

  bool matchingDomain(Domain d, S domain) {

    ret domainIsUnder_extended(domain, d.domain);

  }

  // API

  Cl<Domain> domainsInMatchingOrder() {

    ret sortByCalculatedFieldICDesc(

      filter(list(Domain), d -> !eqic(d.domain, "<default>")),

      d -> reversed(d.domain));

  }

  void addDomain(S domain, S moduleLibID, bool mustBeEnabled) {

    uniq Domain(+domain, +moduleLibID, +mustBeEnabled);

  }

}