Do a .well-known lookup during registration

src/RegisterPage.cpp

@@ -11,6 +11,7 @@
 #include <QtMath>
 
 #include <mtx/responses/register.hpp>
+#include <mtx/responses/well-known.hpp>
 
 #include "Config.h"
 #include "Logging.h"
@@ -145,6 +146,17 @@ RegisterPage::RegisterPage(QWidget *parent)
         top_layout_->addWidget(error_label_, 0, Qt::AlignHCenter);
         top_layout_->addStretch(1);
 
+        connect(
+          this,
+          &RegisterPage::versionErrorCb,
+          this,
+          [this](const QString &msg) {
+                  error_server_label_->show();
+                  server_input_->setValid(false);
+                  showError(error_server_label_, msg);
+          },
+          Qt::QueuedConnection);
+
         connect(back_button_, SIGNAL(clicked()), this, SLOT(onBackButtonClicked()));
         connect(register_button_, SIGNAL(clicked()), this, SLOT(onRegisterButtonClicked()));
 
@@ -414,6 +426,70 @@ RegisterPage::onRegisterButtonClicked()
                 http::client()->set_server(server);
                 http::client()->verify_certificates(
                   !UserSettings::instance()->disableCertificateValidation());
+
+                http::client()->well_known(
+                  [this, username, password](const mtx::responses::WellKnown &res,
+                                             mtx::http::RequestErr err) {
+                          if (err) {
+                                  using namespace boost::beast::http;
+
+                                  if (err->status_code == status::not_found) {
+                                          nhlog::net()->info("Autodiscovery: No .well-known.");
+                                          checkVersionAndRegister(username, password);
+                                          return;
+                                  }
+
+                                  if (!err->parse_error.empty()) {
+                                          emit versionErrorCb(tr(
+                                            "Autodiscovery failed. Received malformed response."));
+                                          nhlog::net()->error(
+                                            "Autodiscovery failed. Received malformed response.");
+                                          return;
+                                  }
+
+                                  emit versionErrorCb(tr("Autodiscovery failed. Unknown error when "
+                                                         "requesting .well-known."));
+                                  nhlog::net()->error("Autodiscovery failed. Unknown error when "
+                                                      "requesting .well-known. {}",
+                                                      err->error_code.message());
+                                  return;
+                          }
+
+                          nhlog::net()->info("Autodiscovery: Discovered '" +
+                                             res.homeserver.base_url + "'");
+                          http::client()->set_server(res.homeserver.base_url);
+                          checkVersionAndRegister(username, password);
+                  });
+
+                emit registering();
+        }
+}
+
+void
+RegisterPage::checkVersionAndRegister(const std::string &username, const std::string &password)
+{
+        http::client()->versions(
+          [this, username, password](const mtx::responses::Versions &, mtx::http::RequestErr err) {
+                  if (err) {
+                          using namespace boost::beast::http;
+
+                          if (err->status_code == status::not_found) {
+                                  emit versionErrorCb(tr("The required endpoints were not found. "
+                                                         "Possibly not a Matrix server."));
+                                  return;
+                          }
+
+                          if (!err->parse_error.empty()) {
+                                  emit versionErrorCb(tr("Received malformed response. Make sure "
+                                                         "the homeserver domain is valid."));
+                                  return;
+                          }
+
+                          emit versionErrorCb(tr(
+                            "An unknown error occured. Make sure the homeserver domain is valid."));
+                          return;
+                  }
+
                   http::client()->registration(
                     username,
                     password,
@@ -454,9 +530,7 @@ RegisterPage::onRegisterButtonClicked()
                             emit registerErrorCb(QString::fromStdString(err->matrix_error.error));
                             emit errorOccurred();
                     });
-
+          });
-                emit registering();
-        }
 }
 
 void

src/RegisterPage.h

@@ -31,6 +31,10 @@ protected:
 signals:
         void backButtonClicked();
         void errorOccurred();
+
+        //! Used to trigger the corresponding slot outside of the main thread.
+        void versionErrorCb(const QString &err);
+
         void registering();
         void registerOk();
         void registerErrorCb(const QString &msg);
@@ -52,6 +56,7 @@ private:
         bool checkOneField(QLabel *label, const TextField *t_field, const QString &msg);
         bool checkFields();
         void showError(QLabel *label, const QString &msg);
+        void checkVersionAndRegister(const std::string &username, const std::string &password);
         QVBoxLayout *top_layout_;
 
         QHBoxLayout *back_layout_;