Add /get_version, based on openmonero with a few extra additions (#209)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1ddc24c..92d5401 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -28,6 +28,35 @@
 
 include_directories(.)
 
+find_package(Git)
+
+set(MLWS_COMMIT_BRANCH "")
+set(MLWS_COMMIT_DATE "")
+set(MLWS_COMMIT_HASH "")
+if (GIT_FOUND)
+  execute_process(
+    COMMAND "${GIT_EXECUTABLE}" rev-parse HEAD
+    WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
+    OUTPUT_VARIABLE MLWS_COMMIT_HASH
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+  execute_process(
+    COMMAND "${GIT_EXECUTABLE}" rev-parse --abbrev-ref HEAD
+    WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
+    OUTPUT_VARIABLE MLWS_COMMIT_BRANCH
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+  execute_process(
+    COMMAND "${GIT_EXECUTABLE}" log -1 "--date=format:\"%Y/%m/%d %T\"" "--format=\"%ad\""
+    WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
+    OUTPUT_VARIABLE MLWS_COMMIT_DATE
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+endif ()
+
+configure_file(lws_version.h.in "${CMAKE_BINARY_DIR}/generated_include/lws_version.h")
+include_directories("${CMAKE_BINARY_DIR}/generated_include")
+
 add_subdirectory(lmdb)
 add_subdirectory(wire)
 add_subdirectory(db)
diff --git a/src/error.cpp b/src/error.cpp
index 39f8fd6..a4db6c9 100644
--- a/src/error.cpp
+++ b/src/error.cpp
@@ -61,6 +61,8 @@ namespace lws
         return "Invalid blockchain height";
       case error::bad_url:
         return "Invlaid URL";
+      case error::bad_verb:
+        return "Incorrect HTTP verb provided";
       case error::bad_webhook:
         return "Invalid webhook request";
       case error::blockchain_reorg:
diff --git a/src/error.h b/src/error.h
index fcc9cc1..ca67de3 100644
--- a/src/error.h
+++ b/src/error.h
@@ -44,6 +44,7 @@ namespace lws
     bad_daemon_response,        //!< RPC Response from daemon was invalid
     bad_height,                 //!< Invalid blockchain height
     bad_url,                    //!< Invalid URL
+    bad_verb,                   //!< Bad HTTP verb for endpoint
     bad_webhook,                //!< Invalid webhook request
     blockchain_reorg,           //!< Blockchain reorg after fetching/scanning block(s)
     configuration,              //!< Process configuration invalid
diff --git a/src/lws_version.h.in b/src/lws_version.h.in
new file mode 100644
index 0000000..e5f0146
--- /dev/null
+++ b/src/lws_version.h.in
@@ -0,0 +1,47 @@
+// Copyright (c) 2025, The Monero Project
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#pragma once
+
+#include <cstdint>
+
+namespace lws { namespace version
+{
+  constexpr const char branch[] = "@MLWS_COMMIT_BRANCH@";
+  constexpr const char commit[] = "@MLWS_COMMIT_HASH@";
+  constexpr const char date[] = "@MLWS_COMMIT_DATE@";
+  constexpr const char id[] = "0.4-alpha";
+  constexpr const char name[] = "monero-lws";
+
+  // openmonero is currently on 1.6 and we have multiple additions since then
+  namespace api
+  {
+    constexpr const std::uint16_t major = 1;
+    constexpr const std::uint16_t minor = 7;
+    constexpr const std::uint32_t combined = std::uint32_t(major) << 16 | minor;
+  }
+}} // lws // version
+
diff --git a/src/rest_server.cpp b/src/rest_server.cpp
index 859a9cc..f27f9b2 100644
--- a/src/rest_server.cpp
+++ b/src/rest_server.cpp
@@ -159,10 +159,11 @@ namespace lws
     struct connection_data
     {
       rest_server_data* const global; //!< Valid for lifetime of server
+      boost::beast::http::verb last_verb; 
       bool passed_login; //!< True iff a login via viewkey was successful
 
       explicit connection_data(rest_server_data* global) noexcept
-        : global(global), passed_login(false)
+        : global(global), last_verb(boost::beast::http::verb::unknown), passed_login(false)
       {}
 
       //! \return Next request timeout, based on login status
@@ -300,7 +301,7 @@ namespace lws
       using response = epee::byte_slice; // sometimes async
       using async_response = rpc::daemon_status_response;
 
-      static expect<response> handle(const request&, const connection_data& data, std::function<async_complete>&& resume)
+      static expect<response> handle(request, const connection_data& data, std::function<async_complete>&& resume)
       {
         using info_rpc = cryptonote::rpc::GetInfo;
 
@@ -1303,6 +1304,33 @@ namespace lws
       }
     };
 
+    struct get_version
+    {
+      using request = rpc::get_version_request;
+      using response = rpc::get_version_response;
+
+      static expect<response> handle(request, const connection_data& data, std::function<async_complete>&&)
+      {
+        lws::db::block_id height{};
+        {
+          auto reader = data.global->disk.start_read();
+          if (reader)
+          {
+            auto db_height = reader->get_last_block();
+            if (db_height)
+              height = db_height->id;
+            else
+              MWARNING("Failed to get DB height: " << db_height.error().message());
+          }
+          else
+            MWARNING("Failed to start db reader: " << reader.error().message());
+        }
+
+        // response constructor fills remaining fields
+        return response{height, data.global->options.max_subaddresses};
+      }
+    };
+
     struct import_request
     {
       using request = rpc::import_request;
@@ -1710,11 +1738,16 @@ namespace lws
         throw std::logic_error{"async REST handler not setup properly"};
       if (std::is_same<epee::byte_slice, response>() && !resume)
         throw std::logic_error{"async REST handler not setup properly"};
-
+ 
       request req{};
-      std::error_code error = wire::json::from_bytes(std::move(root), req);
-      if (error)
-        return error;
+      if (!std::is_empty<request>())
+      {
+        if (data.last_verb != boost::beast::http::verb::post)
+          return {error::bad_verb};
+        std::error_code error = wire::json::from_bytes(std::move(root), req);
+        if (error)
+          return error;
+      }
 
       expect<response> resp = E::handle(std::move(req), data, std::move(resume));
       if (!resp)
@@ -1744,6 +1777,9 @@ namespace lws
     expect<epee::byte_slice> call_admin(std::string&& root, connection_data& data, std::function<async_complete>&&)
     {
       using request = typename E::request;
+
+      if (data.last_verb != boost::beast::http::verb::post)
+        return {error::bad_verb};
       
       admin<request> req{};
       {
@@ -1804,6 +1840,7 @@ namespace lws
       {"/get_subaddrs",          call<get_subaddrs>,       2 * 1024, false},
       {"/get_txt_records",       nullptr,                         0, false},
       {"/get_unspent_outs",      call<get_unspent_outs>,   2 * 1024,  true},
+      {"/get_version",           call<get_version>,            1024, false},
       {"/import_wallet_request", call<import_request>,     2 * 1024, false},
       {"/login",                 call<login>,              2 * 1024, false},
       {"/provision_subaddrs",    call<provision_subaddrs>, 2 * 1024, false},
@@ -2010,6 +2047,8 @@ namespace lws
       assert(strand_.running_in_this_thread());
       if (error.category() == wire::error::rapidjson_category() || error == lws::error::invalid_range || error == lws::error::not_enough_amount)
         return bad_request(boost::beast::http::status::bad_request, std::forward<F>(resume));
+      else if (error == lws::error::bad_verb)
+        return bad_request(boost::beast::http::status::method_not_allowed, std::forward<F>(resume));
       else if (error == lws::error::account_not_found || error == lws::error::duplicate_request)
         return bad_request(boost::beast::http::status::forbidden, std::forward<F>(resume));
       else if (error == lws::error::max_subaddresses)
@@ -2119,7 +2158,8 @@ namespace lws
         return self_->bad_request(boost::beast::http::status::bad_request, std::forward<F>(resume));
       }
 
-      if (self_->parser_->get().method() != boost::beast::http::verb::post)
+      const boost::beast::http::verb verb = self_->parser_->get().method();
+      if (verb != boost::beast::http::verb::post && verb != boost::beast::http::verb::get)
         return self_->bad_request(boost::beast::http::status::method_not_allowed, std::forward<F>(resume));
 
       std::function<async_complete> resumer;
@@ -2143,6 +2183,7 @@ namespace lws
       }
 
       MDEBUG("Running REST handler " << handler->name << " on " << self_.get());
+      self_->data_.last_verb = verb;
       auto body = handler->run(std::move(self_->parser_->get()).body(), self_->data_, std::move(resumer));
       if (!body)
         return self_->bad_request(body.error(), std::forward<F>(resume));
diff --git a/src/rpc/light_wallet.cpp b/src/rpc/light_wallet.cpp
index adc83bc..3ab20c9 100644
--- a/src/rpc/light_wallet.cpp
+++ b/src/rpc/light_wallet.cpp
@@ -37,10 +37,12 @@
 #include "config.h"
 #include "db/string.h"
 #include "error.h"
+#include "lws_version.h"
 #include "time_helper.h"       // monero/contrib/epee/include
 #include "ringct/rctOps.h"     // monero/src
 #include "span.h"              // monero/contrib/epee/include
 #include "util/random_outputs.h"
+#include "version.h"           // monero/src
 #include "wire.h"
 #include "wire/adapted/crypto.h"
 #include "wire/error.h"
@@ -362,6 +364,36 @@ namespace lws
     );
   }
 
+  rpc::get_version_response::get_version_response(const db::block_id height, const std::uint32_t max_subaddresses)
+    : server_type(lws::version::name),
+      server_version(lws::version::id),
+      last_git_commit_hash(lws::version::commit),
+      last_git_commit_date(lws::version::date),
+      git_branch_name(lws::version::branch),
+      monero_version_full(MONERO_VERSION_FULL),
+      blockchain_height(height),
+      api(lws::version::api::combined),
+      max_subaddresses(max_subaddresses),
+      network(lws::rpc::network_type(lws::config::network)),
+      testnet(config::network == cryptonote::TESTNET) 
+  {}
+  void rpc::write_bytes(wire::json_writer& dest, const get_version_response& self)
+  {
+    wire::object(dest,
+      WIRE_FIELD(server_type),
+      WIRE_FIELD(server_version),
+      WIRE_FIELD(last_git_commit_hash),
+      WIRE_FIELD(last_git_commit_date),
+      WIRE_FIELD(git_branch_name),
+      WIRE_FIELD(monero_version_full),
+      WIRE_FIELD_COPY(blockchain_height),
+      WIRE_FIELD(api),
+      WIRE_FIELD_COPY(max_subaddresses),
+      wire::field("network_type", self.network),
+      WIRE_FIELD_COPY(testnet)
+    );
+  }
+
   void rpc::read_bytes(wire::json_reader& source, import_request& self)
   {
     std::string address;
diff --git a/src/rpc/light_wallet.h b/src/rpc/light_wallet.h
index dc78199..5d6ffb8 100644
--- a/src/rpc/light_wallet.h
+++ b/src/rpc/light_wallet.h
@@ -224,6 +224,35 @@ namespace rpc
   void write_bytes(wire::json_writer&, const get_subaddrs_response&);
 
 
+  struct get_version_request
+  {
+    get_version_request() = delete;
+  };
+  inline void read_bytes(const wire::reader&, const get_version_request&)
+  {}
+
+  struct get_version_response
+  {
+    //! Defaults to current network in unavailable state
+    get_version_response(lws::db::block_id height, std::uint32_t max_subaddresses);
+
+   
+    const std::string server_type;
+    const std::string server_version;
+    const std::string last_git_commit_hash;
+    const std::string last_git_commit_date;
+    const std::string git_branch_name;
+    const std::string monero_version_full;
+
+    const db::block_id blockchain_height;
+    const std::uint32_t api;
+    const std::uint32_t max_subaddresses;
+    const network_type network;
+    const bool testnet; 
+  };
+  void write_bytes(wire::json_writer&, const get_version_response&);
+
+
   struct import_request
   {
     import_request() = delete;