!7

concept Domain {

  S domain;

  S moduleLibID;

  S proxyDestination;

  S proxyCookieChecker; // a module lib ID

  bool proxyRewritePort;

  bool mustBeEnabled;

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

}

// Eleu is so important, we don't use a shared lib

module Eleu3 > DynEleu {

  transient CRUD<Domain> domainCRUD;

  switchable bool verbose;

  switchable bool debugNanoHTTPD;

  switchable S sameSite;

  {} { enabled = false; }

  start {

    NanoHTTPD_debug = debugNanoHTTPD;

    bootstrapDBFrom(#1029618);

    set flag defaultDefaultClassFinder_debug.

    dbIndexingCI(Domain, 'domain);

    assertNempty(list(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"));

          else

            print("Cookie checker approves. URI: " + session.getUri());

        }

        new HandleProxyRequest hpr;

        hpr.hap = hap;

        hpr.session = session;

        hpr.rewritePort = d.proxyRewritePort;

        hpr.customizeRequest = proxyRequest -> {

          proxyRequest.setOut = out -> {

            proxyRequest.setOut_base(out);

            proxyRequest.outProxied = out; // mod here

          };

          proxyRequest.setOutOut = outOut -> {

            proxyRequest.setOutOut_base(outOut);

            proxyRequest.outOutProxied = outOut; // mod here

          };

        };

        vmBus_send handlingProxyRequest(me(), hpr);

        ret true with hpr.run();

      };

    });

  } // onWebServersStarted

  bool matchingDomain(Domain d, S domain) {

    ret domainIsUnder_extended(domain, d.domain);

  }

  class WebRequest2 extends WebRequest {

    *(NanoHTTPD.IHTTPSession httpSession, S uri, SS params) {

      super(httpSession, uri, params);

    }

    // TODO: change uri etc

    /*public NanoHTTPD.Response proxy(S url, bool rewriteHost, bool rewritePort) {

      url = dropPrefix("http://", url);

      if (startsWith(url, "https://"))

      new HandleProxyRequest hpr;

      hpr.hap = hap;

      hpr.session = httpSession;

      hpr.rewriteHost = rewriteHost;

      hpr.rewritePort = rewritePort;

      hpr.run();

      null;

    }*/

  }

  @Override

  WebRequest createWebRequest(NanoHTTPD.IHTTPSession httpSession,

    S uri, SS params) {

    ret new WebRequest2(httpSession, uri, params);

  }

  // 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);

  }

}