From bb336da4d9020bb26a6c3e762d74a0c23c9330dc Mon Sep 17 00:00:00 2001
From: sha512sum <linuxnyasha@tutanota.com>
Date: Sun, 6 Oct 2024 18:56:10 +0000
Subject: [PATCH] Add Stream Errors

---
 CMakeLists.txt                           |   5 +-
 library/include/larra/raw_xml_stream.hpp |  66 ++---------
 library/include/larra/serialization.hpp  | 143 +++++++++++++++++++++++
 library/include/larra/stream_error.hpp   | 138 ++++++++++++++++++++++
 tests/serialization.cpp                  |  28 +++++
 5 files changed, 320 insertions(+), 60 deletions(-)
 create mode 100644 library/include/larra/serialization.hpp
 create mode 100644 library/include/larra/stream_error.hpp
 create mode 100644 tests/serialization.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index de8f26c..d37d3c4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -55,6 +55,7 @@ CPMAddPackage(
 
 CPMAddPackage("gh:zeux/pugixml@1.14")
 CPMAddPackage("gh:fmtlib/fmt#10.2.1")
+CPMAddPackage("gh:Neargye/nameof@0.10.4")
 
 CPMAddPackage(
   NAME spdlog
@@ -162,12 +163,14 @@ target_include_directories(larra_xmpp PUBLIC
 
 if(TARGET Boost::pfr)
   target_link_libraries(larra_xmpp PUBLIC
-    Boost::asio Boost::serialization utempl::utempl pugixml::pugixml OpenSSL::SSL
+    Boost::asio Boost::serialization utempl::utempl pugixml::pugixml
+    OpenSSL::SSL nameof::nameof
     OpenSSL::Crypto spdlog xmlplusplus ${LIBXML2_LIBRARIES})
 else()
   find_package(Boost 1.85.0 REQUIRED)
   target_link_libraries(larra_xmpp PUBLIC
     utempl::utempl ${Boost_LIBRARIES} pugixml::pugixml OpenSSL::SSL
+    nameof::nameof
     OpenSSL::Crypto spdlog xmlplusplus ${LIBXML2_LIBRARIES})
 endif()
 
diff --git a/library/include/larra/raw_xml_stream.hpp b/library/include/larra/raw_xml_stream.hpp
index 42b9918..3ff16a5 100644
--- a/library/include/larra/raw_xml_stream.hpp
+++ b/library/include/larra/raw_xml_stream.hpp
@@ -9,6 +9,7 @@
 #include <boost/asio/use_awaitable.hpp>
 #include <boost/asio/write.hpp>
 #include <boost/system/result.hpp>
+#include <larra/serialization.hpp>
 #include <larra/utils.hpp>
 #include <stack>
 #include <utempl/utils.hpp>
@@ -17,32 +18,6 @@ struct _xmlError;
 
 namespace larra::xmpp {
 
-template <typename T>
-concept AsXml = requires(xmlpp::Element* element, const T& obj) {
-  element << obj;
-  { T::kDefaultName } -> std::convertible_to<const std::string&>;
-};
-
-template <typename T>
-concept HasDefaultNamespace = requires {
-  { T::kDefaultNamespace } -> std::convertible_to<const std::string&>;
-};
-
-template <typename T>
-concept HasDefaultPrefix = requires {
-  { T::kPrefix } -> std::convertible_to<const std::string&>;
-};
-
-template <typename T>
-concept HasAddXmlDecl = requires {
-  { T::kAddXmlDecl } -> std::convertible_to<bool>;
-};
-
-template <typename T>
-concept HasRemoveEnd = requires {
-  { T::kRemoveEnd } -> std::convertible_to<bool>;
-};
-
 struct XmlGroup : xmlpp::Element {
   using Element::Element;
 };
@@ -240,16 +215,16 @@ struct RawXmlStream : Stream {
   template <typename T>
   auto Read(auto& stream) -> boost::asio::awaitable<T> {
     auto doc = co_await this->Read(stream);
-    co_return T::Parse(doc->get_root_node());
+    co_return Serialization<T>::Parse(doc->get_root_node());
   }
 
   template <typename T>
   auto Read(auto& stream) -> boost::asio::awaitable<T>
     requires requires(std::unique_ptr<xmlpp::Document> ptr) {
-      { T::Parse(std::move(ptr)) } -> std::same_as<T>;
+      { Serialization<T>::Parse(std::move(ptr)) } -> std::same_as<T>;
     }
   {
-    co_return T::Parse(co_await this->Read(stream));
+    co_return Serialization<T>::Parse(co_await this->Read(stream));
   }
 
   template <typename T>
@@ -286,36 +261,9 @@ struct RawXmlStream : Stream {
   template <AsXml T>
   auto Send(const T& xso, auto& stream) const -> boost::asio::awaitable<void> {
     xmlpp::Document doc;
-    const std::string empty;
-    const std::string namespaceStr = [&] -> std::string {
-      if constexpr(HasDefaultNamespace<T>) {
-        return T::kDefaultNamespace;
-      } else {
-        return empty;
-      }
-    }();
-    const std::string prefixStr = [&] -> decltype(auto) {
-      if constexpr(HasDefaultPrefix<T>) {
-        return T::kPrefix;
-      } else {
-        return empty;
-      }
-    }();
-    const bool bAddXmlDecl = [&] -> bool {
-      if constexpr(HasAddXmlDecl<T>) {
-        return T::kAddXmlDecl;
-      }
-      return false;
-    }();
-    const bool removeEnd = [&] -> bool {
-      if constexpr(HasRemoveEnd<T>) {
-        return T::kRemoveEnd;
-      }
-      return false;
-    }();
-
-    doc.create_root_node(T::kDefaultName, namespaceStr, prefixStr) << xso;
-    co_await this->Send(doc, stream, bAddXmlDecl, removeEnd);
+    using S = Serialization<std::decay_t<T>>;
+    S::Serialize(doc.create_root_node(S::kDefaultName, S::kDefaultNamespace, S::kPrefix), xso);
+    co_await this->Send(doc, stream, S::kAddXmlDecl, S::kRemoveEnd);
   }
 
   auto Send(const AsXml auto& xso) -> boost::asio::awaitable<void> {
diff --git a/library/include/larra/serialization.hpp b/library/include/larra/serialization.hpp
new file mode 100644
index 0000000..ae2fc4e
--- /dev/null
+++ b/library/include/larra/serialization.hpp
@@ -0,0 +1,143 @@
+#pragma once
+#include <libxml++/libxml++.h>
+#include <spdlog/spdlog.h>
+
+#include <string>
+#include <utempl/utils.hpp>
+
+namespace larra::xmpp {
+
+template <typename T>
+concept AsXml = requires(xmlpp::Element* element, const T& obj) {
+  element << obj;
+  { T::kDefaultName } -> std::convertible_to<const std::string&>;
+};
+
+template <typename T>
+concept HasDefaultName = requires {
+  { T::kDefaultName } -> std::convertible_to<const std::string&>;
+};
+
+template <typename T>
+concept HasDefaultNamespace = requires {
+  { T::kDefaultNamespace } -> std::convertible_to<const std::string&>;
+};
+
+template <typename T>
+concept HasDefaultPrefix = requires {
+  { T::kPrefix } -> std::convertible_to<const std::string&>;
+};
+
+template <typename T>
+concept HasAddXmlDecl = requires {
+  { T::kAddXmlDecl } -> std::convertible_to<bool>;
+};
+
+template <typename T>
+concept HasRemoveEnd = requires {
+  { T::kRemoveEnd } -> std::convertible_to<bool>;
+};
+
+template <typename T>
+concept HasTryParse = requires(xmlpp::Element* element) {
+  { T::TryParse(element) } -> std::same_as<std::optional<T>>;
+};
+
+template <typename T = void>
+struct SerializationBase {
+  inline static const std::string kDefaultName = [] {
+    if constexpr(HasDefaultName<T>) {
+      return T::kDefaultName;
+    } else {
+      return "";
+    }
+  }();
+  inline static const std::string kDefaultNamespace = [] {
+    if constexpr(HasDefaultNamespace<T>) {
+      return T::kDefaultNamespace;
+    } else {
+      return "";
+    }
+  }();
+  inline static const std::string kPrefix = [] {
+    if constexpr(HasDefaultPrefix<T>) {
+      return T::kPrefix;
+    } else {
+      return "";
+    }
+  }();
+  static constexpr bool kAddXmlDecl = [] {
+    if constexpr(HasAddXmlDecl<T>) {
+      return T::kAddXmlDecl;
+    } else {
+      return false;
+    }
+  }();
+  static constexpr bool kRemoveEnd = [] {
+    if constexpr(HasRemoveEnd<T>) {
+      return T::kRemoveEnd;
+    } else {
+      return false;
+    }
+  }();
+};
+
+template <typename T>
+struct Serialization : SerializationBase<T> {
+  [[nodiscard]] static constexpr auto Parse(xmlpp::Element* element) -> T {
+    return T::Parse(element);
+  }
+  [[nodiscard]] static constexpr auto TryParse(xmlpp::Element* element) -> std::optional<T> {
+    if constexpr(HasTryParse<T>) {
+      return T::TryParse(element);
+    } else {
+      try {
+        return T::Parse(element);
+      } catch(const std::exception& e) {
+        SPDLOG_WARN("Failed Parse but no TryParse found: {}", e.what());
+      } catch(...) {
+        SPDLOG_WARN("Failed Parse but no TryParse found");
+      }
+      return std::nullopt;
+    }
+  };
+  static constexpr auto Serialize(xmlpp::Element* element, const T& object) -> void {
+    element << object;
+  }
+};
+
+template <typename T>
+struct Serialization<std::optional<T>> : SerializationBase<T> {
+  [[nodiscard]] static constexpr auto Parse(xmlpp::Element* element) -> std::optional<T> {
+    return Serialization<T>::TryParse(element);
+  }
+  [[nodiscard]] static constexpr auto TryParse(xmlpp::Element* element) -> std::optional<std::optional<T>> {
+    auto response = Serialization<T>::TryParse(element);
+    return response ? *response : std::nullopt;
+  }
+  static constexpr auto Serialize(xmlpp::Element* element, const T& object) -> void {
+    element << object;
+  }
+};
+
+template <typename... Ts>
+struct Serialization<std::variant<Ts...>> : SerializationBase<> {
+  [[nodiscard]] static constexpr auto TryParse(xmlpp::Element* element) -> std::optional<std::variant<Ts...>> {
+    return utempl::FirstOf(utempl::Tuple{[&] {
+                             return Serialization<Ts>::TryParse(element);
+                           }...},
+                           std::optional<std::variant<Ts...>>{});
+  }
+  [[nodiscard]] static constexpr auto Parse(xmlpp::Element* element) -> std::variant<Ts...> {
+    return Serialization::TryParse(element).value();
+  }
+  static constexpr auto Serialize(xmlpp::Element* element, const std::variant<Ts...>& object) -> void {
+    std::visit(
+        [&](const auto& object) {
+          element << object;
+        },
+        object);
+  }
+};
+
+}  // namespace larra::xmpp
diff --git a/library/include/larra/stream_error.hpp b/library/include/larra/stream_error.hpp
new file mode 100644
index 0000000..e707608
--- /dev/null
+++ b/library/include/larra/stream_error.hpp
@@ -0,0 +1,138 @@
+#pragma once
+#include <libxml++/libxml++.h>
+
+#include <algorithm>
+#include <nameof.hpp>
+#include <ranges>
+#include <variant>
+
+namespace larra::xmpp {
+
+namespace impl {
+// std::isupper not declared as constexpr
+constexpr auto IsUpper(char ch) -> bool {
+  return ch >= 'A' && ch <= 'Z';
+}
+
+constexpr auto ToLower(char ch) -> char {
+  return (ch >= 'A' && ch <= 'Z') ? static_cast<char>(ch + ('a' - 'A')) : ch;
+}
+
+template <typename T>
+constexpr auto ToKebabCaseName() -> std::string_view {
+  static constexpr auto rawStr = nameof::nameof_short_type<T>();
+
+  constexpr auto str = [] {
+    return rawStr | std::views::transform([](auto ch) {
+             return impl::IsUpper(ch) ? std::array<char, 2>{'-', impl::ToLower(ch)} : std::array<char, 2>{ch, '\0'};
+           }) |
+           std::views::join | std::views::filter([](char ch) {
+             return ch != '\0';
+           });
+  };
+  constexpr auto size = std::ranges::fold_left(str(),
+                                               std::size_t{},
+                                               [](auto accum, auto) {
+                                                 return accum + 1;
+                                               }) -
+                        1;
+  static constexpr auto arr = [&] {
+    std::array<char, size> response;  // NOLINT
+    std::ranges::copy(str() | std::views::drop(1), response.begin());
+    return response;
+  }();
+  return {arr.data(), size};
+}
+
+}  // namespace impl
+
+namespace error::stream {
+
+template <typename T>
+struct BaseError : std::exception {
+  static constexpr auto kDefaultName = "error";
+  static constexpr auto kDefaultNamespace = "stream";
+  static inline const auto kKebabCaseName = static_cast<std::string>(impl::ToKebabCaseName<T>());
+  static inline const std::string kErrorContentNamespace = "urn:ietf:params:xml:ns:xmpp-streams";
+  static constexpr auto kErrorMessage = [] -> std::string_view {
+    static constexpr auto str = [] {
+      return std::array{std::string_view{"Stream Error: "}, nameof::nameof_short_type<T>(), std::string_view{"\0", 1}} | std::views::join;
+    };
+    constexpr auto size = std::ranges::fold_left(str(), std::size_t{}, [](auto accum, auto) {
+      return accum + 1;
+    });
+    static constexpr auto array = [] {
+      std::array<char, size> response;  // NOLINT
+      std::ranges::copy(str(), response.begin());
+      return response;
+    }();
+    return {array.data(), array.size() - 1};
+  }();
+  static constexpr auto TryParse(xmlpp::Element* element) -> std::optional<T> {
+    return element ? element->get_first_child(kKebabCaseName) ? std::optional{T{}} : std::nullopt : std::nullopt;
+  }
+  static constexpr auto Parse(xmlpp::Element* element) -> T {
+    return TryParse(element).value();
+  }
+  friend constexpr auto operator<<(xmlpp::Element* element, const T& obj) -> void {
+    auto node = element->add_child_element(kKebabCaseName);
+    node->set_namespace_declaration(kErrorContentNamespace);
+  }
+  [[nodiscard]] constexpr auto what() const noexcept -> const char* override {
+    return kErrorMessage.data();
+  }
+};
+
+struct BadFormat : BaseError<BadFormat> {};
+struct BadNamespacePrefix : BaseError<BadNamespacePrefix> {};
+struct Conflict : BaseError<Conflict> {};
+struct ConnectionTimeout : BaseError<ConnectionTimeout> {};
+struct HostGone : BaseError<HostGone> {};
+struct HostUnknown : BaseError<HostUnknown> {};
+struct ImproperAdressing : BaseError<ImproperAdressing> {};
+struct InternalServerError : BaseError<InternalServerError> {};
+struct InvalidForm : BaseError<InvalidForm> {};
+struct InvalidNamespace : BaseError<InvalidNamespace> {};
+struct InvalidXml : BaseError<InvalidXml> {};
+struct NotAuthorized : BaseError<NotAuthorized> {};
+struct NotWellFormed : BaseError<NotWellFormed> {};
+struct PolicyViolation : BaseError<PolicyViolation> {};
+struct RemoteConnectionFailed : BaseError<RemoteConnectionFailed> {};
+struct Reset : BaseError<Reset> {};
+struct ResourceConstraint : BaseError<ResourceConstraint> {};
+struct RestrictedXml : BaseError<RestrictedXml> {};
+struct SeeOtherHost : BaseError<SeeOtherHost> {};
+struct SystemShutdown : BaseError<SystemShutdown> {};
+struct UndefinedCondition : BaseError<UndefinedCondition> {};
+struct UnsupportedEncoding : BaseError<UnsupportedEncoding> {};
+struct UnsupportedFeature : BaseError<UnsupportedFeature> {};
+struct UnsupportedStanzaType : BaseError<UnsupportedStanzaType> {};
+struct UnsupportedVersion : BaseError<UnsupportedVersion> {};
+
+}  // namespace error::stream
+
+using StreamError = std::variant<error::stream::BadFormat,
+                                 error::stream::BadNamespacePrefix,
+                                 error::stream::Conflict,
+                                 error::stream::ConnectionTimeout,
+                                 error::stream::HostGone,
+                                 error::stream::HostUnknown,
+                                 error::stream::ImproperAdressing,
+                                 error::stream::InternalServerError,
+                                 error::stream::InvalidForm,
+                                 error::stream::InvalidNamespace,
+                                 error::stream::InvalidXml,
+                                 error::stream::NotAuthorized,
+                                 error::stream::NotWellFormed,
+                                 error::stream::PolicyViolation,
+                                 error::stream::RemoteConnectionFailed,
+                                 error::stream::RestrictedXml,
+                                 error::stream::SeeOtherHost,
+                                 error::stream::SystemShutdown,
+                                 error::stream::UndefinedCondition,
+                                 error::stream::UnsupportedEncoding,
+                                 error::stream::UnsupportedFeature,
+                                 error::stream::UnsupportedStanzaType,
+                                 error::stream::UnsupportedVersion>;
+
+}  // namespace larra::xmpp
diff --git a/tests/serialization.cpp b/tests/serialization.cpp
new file mode 100644
index 0000000..89e23ac
--- /dev/null
+++ b/tests/serialization.cpp
@@ -0,0 +1,28 @@
+#include <gtest/gtest.h>
+
+#include <larra/serialization.hpp>
+#include <larra/stream_error.hpp>
+
+namespace larra::xmpp {
+
+TEST(Parse, Variant) {
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("stream:error");
+  node->add_child_element("unsupported-stanza-type");
+  node->set_namespace_declaration("urn:ietf:params:xml:ns:xmpp-streams");
+  auto streamError = Serialization<StreamError>::Parse(node);
+  EXPECT_TRUE(std::get_if<error::stream::UnsupportedStanzaType>(&streamError));
+}
+
+TEST(Serialize, Variant) {
+  using S = Serialization<StreamError>;
+  StreamError data = error::stream::UnsupportedStanzaType{};
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("stream:error");
+  S::Serialize(node, data);
+  EXPECT_EQ(doc.write_to_string(),
+            std::string_view{"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<stream:error><unsupported-stanza-type "
+                             "xmlns=\"urn:ietf:params:xml:ns:xmpp-streams\"/></stream:error>\n"});
+}
+
+}  // namespace larra::xmpp