1 files changed, 221 insertions, 0 deletions

diff --git a/server/src/srv.cppm b/server/src/srv.cppm
new file mode 100644
index 0000000..2ca48c6
--- /dev/null
+++ b/server/src/srv.cppm
@@ -0,0 +1,221 @@
+module;
+
+#include <boost/config.hpp>
+#include <boost/asio/ip/tcp.hpp>
+#include <boost/asio/as_tuple.hpp>
+#include <boost/asio/awaitable.hpp>
+#include <boost/asio/co_spawn.hpp>
+#include <boost/beast/core.hpp>
+#include <boost/beast/http.hpp>
+#include <boost/json.hpp>
+#include <boost/locale/generator.hpp>
+
+#include <expat.h>
+
+export module routemon:srv;
+
+import std;
+import :api;
+import :config;
+import :gpx;
+import :http.server;
+import :locale;
+import :log;
+import :problem;
+import :req_ctx;
+import :util;
+
+namespace beast = boost::beast;
+namespace json = boost::json;
+namespace net = boost::asio;
+using tcp = boost::asio::ip::tcp;
+
+namespace routemon::srv {
+
+  class gpx_parse_error_category_impl : public std::error_category {
+  public:
+    char const* name() const noexcept override { return "gpx_parse"; }
+    auto message(int condition) const noexcept -> std::string override {
+      std::ignore = condition;
+      return "failed to parse GPX file";
+    }
+  };
+  auto gpx_parse_error_category() noexcept -> gpx_parse_error_category_impl const& {
+    static auto const inst = gpx_parse_error_category_impl{};
+    return inst;
+  }
+  auto gpx_parse_error() noexcept -> std::error_code {
+    return std::error_code{1, gpx_parse_error_category()};
+  }
+
+  class gpx_parse_result {
+    std::variant<std::exception_ptr, gpx::file> res_;
+
+  public:
+    auto set_exception(std::exception_ptr ex) noexcept {
+      res_ = ex;
+    }
+    auto set_gpx_file(gpx::file&& f) noexcept {
+      res_ = std::move(f);
+    }
+
+    auto unwrap() -> gpx::file&& {
+      return std::visit(util::overloaded{
+          [](std::exception_ptr ex) -> gpx::file&& {
+            if (ex) std::rethrow_exception(ex);
+            else throw std::runtime_error{"no GPX file parse result available"};
+          },
+          [](gpx::file&& f) -> gpx::file&& { return std::move(f); },
+        }, std::move(res_));
+    }
+  };
+
+  struct readable_gpx_body {
+    using value_type = gpx_parse_result;
+
+    class reader {
+      gpx::reader r_;
+      util::not_null<value_type*> res_;
+
+    public:
+      template<bool isRequest, bhttp::concepts::fields Fields>
+      explicit reader(bhttp::header<isRequest, Fields>&, value_type& v)
+        : res_{&v}
+      {}
+
+      // The following methods (which are called by Beast) are marked
+      // noexcept, since Beast does not ensure that exceptions thrown
+      // here are appropriately directed to the caller of
+      // (async_)read(_some), so throwing here might cause the program
+      // to crash.
+
+      auto init(boost::optional<std::uint64_t> /* n */, beast::error_code& ec) noexcept -> void {
+        try {
+          r_.init();
+          ec = {};
+        } catch (std::exception& ex) {
+          res_->set_exception(std::current_exception());
+          ec = gpx_parse_error();
+        }
+      }
+
+      auto put(beast::concepts::const_buffer_sequence auto b, beast::error_code& ec) noexcept -> std::size_t {
+        auto total = 0uz;
+        try {
+          for (auto it = net::buffer_sequence_begin(b); it != net::buffer_sequence_end(b); it++) {
+            r_.put(std::string_view{static_cast<char const*>(it->data()), it->size()});
+            total += it->size();
+          }
+          ec = {};
+        } catch (std::exception& ex) {
+          res_->set_exception(std::current_exception());
+          ec = gpx_parse_error();
+        }
+        return total;
+      }
+
+      auto finish(beast::error_code& ec) noexcept {
+        try {
+          res_->set_gpx_file(r_.finish());
+          ec = {};
+        } catch (std::exception& ex) {
+          res_->set_exception(std::current_exception());
+          ec = gpx_parse_error();
+        }
+      }
+    };
+  };
+  static_assert(bhttp::concepts::body<readable_gpx_body>);
+  static_assert(bhttp::concepts::body_reader<readable_gpx_body>);
+
+  class handler {
+    api::handler inner_;
+
+  public:
+    using outer_ctx = http::trace_id_ctx<http::base_ctx>;
+    using l0_ctx = http::routed_ctx<outer_ctx>;
+
+  private:
+    auto handle_process_gpx(l0_ctx ctx, http::readable_request r) -> net::awaitable<http::presponse> {
+      auto gpx_file = gpx::file{};
+      try {
+        auto req = co_await http::read_request<readable_gpx_body>(ctx, std::move(r));
+        gpx_file = std::move(req->body().unwrap());
+      } catch (std::exception& ex) {
+        // TODO: more detailed problem reporting
+        auto tpl = problem::tpl{
+          .status   = bhttp::status::bad_request,
+          .title    = translate("Failed to parse GPX file"),
+          .type_uri = "https://routemon.fautchen.eu/problems/gpx-parse-failed",
+        };
+        co_return http::problem_rsp(ctx, tpl.instantiate(), http::keep_alive{false});
+      }
+
+      // TODO: catch handler exceptions and return 500 when raised?
+      // (keep-alive depends on whether whole request was read)
+      auto mres = inner_.process_gpx(std::move(gpx_file));
+      if (!mres) {
+        auto tpl = problem::tpl{
+          .status   = bhttp::status::internal_server_error,
+          .title    = translate("Internal server error"),
+          .type_uri = "https://routemon.fautchen.eu/problems/internal-server-error",
+        };
+        co_return http::problem_rsp(ctx, tpl.instantiate(), http::keep_alive{true});
+      }
+
+      auto rsp = http::make_rsp<bhttp::string_body>(bhttp::status::ok, http::keep_alive{true});
+      rsp.set(bhttp::field::content_type, "application/json");
+      rsp.body() = json::serialize(json::value_from(*mres));
+      rsp.prepare_payload();
+      co_return rsp;
+    }
+
+    auto handle_sysinfo(l0_ctx ctx, http::readable_request r) -> net::awaitable<http::presponse> {
+      auto req = co_await http::read_request<bhttp::empty_body>(ctx, std::move(r));
+      auto info = inner_.sysinfo();
+
+      auto rsp = http::make_rsp<bhttp::string_body>(bhttp::status::ok, http::keep_alive{true});
+      rsp.set(bhttp::field::content_type, "application/json");
+      rsp.body() = json::serialize(json::value_from(info));
+      rsp.prepare_payload();
+      co_return rsp;
+    }
+
+  public:
+    handler(api::handler&& inner) : inner_{std::move(inner)} {}
+
+    auto make_routes() -> http::route_tree<http::routed_ctx<outer_ctx>> {
+      auto handler = [this]<class MemFn>(MemFn member) {
+        return std::bind_front(member, this);
+      };
+
+      return http::dtree<http::routed_ctx<outer_ctx>>{}.named_subtrees({
+          {"gpx", http::dtree<l0_ctx>{{
+                .post = handler(&handler::handle_process_gpx),
+              }}.no_subtrees()},
+          {"sysinfo", http::dtree<l0_ctx>{{
+                .get = handler(&handler::handle_sysinfo),
+              }}.no_subtrees()},
+        });
+    }
+  };
+
+  export class server {
+    handler handler_;
+    http::server<handler::outer_ctx> srv_;
+
+    static auto make_global_middleware() -> http::middleware_t<http::base_ctx, handler::outer_ctx> {
+      return http::middleware_compose<http::base_ctx, http::trace_id_ctx<http::base_ctx>, http::trace_id_ctx<http::base_ctx>>(http::trace_id_middleware<http::base_ctx>, http::lax_cors_middleware<http::trace_id_ctx<http::base_ctx>>);
+    }
+
+  public:
+    server(log::logger const& l, locale::selector&& lsel, api::handler&& inner)
+      : handler_{std::move(inner)}, srv_{l, std::move(lsel), make_global_middleware(), handler_.make_routes()}
+    {}
+
+    auto spawn(net::io_context& ioc) -> void {
+      srv_.spawn(ioc);
+    }
+  };
+
+} // namespace routemon::srv