From 35878b76049b9c3e752480e9f298b7e2da6fdf1f Mon Sep 17 00:00:00 2001
From: Rutger Broekhoff
Date: Fri, 28 Aug 2026 23:29:00 +0200
Subject: Make RWGPS config optional

---
 server/src/config.cpp | 40 +++++++++++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 11 deletions(-)

(limited to 'server/src/config.cpp')

diff --git a/server/src/config.cpp b/server/src/config.cpp
index eab97b5..5c1a161 100644
--- a/server/src/config.cpp
+++ b/server/src/config.cpp
@@ -23,9 +23,9 @@ class location
   {
     if (next_)
     {
+      next_->second->append_to(s);
       s += next_->first;
       s += ".";
-      next_->second->append_to(s);
     }
   }
 
@@ -41,8 +41,9 @@ public:
   {
     if (!next_)
       return "";
-    auto s = std::string{next_->first};
+    auto s = std::string{};
     next_->second->append_to(s);
+    s += next_->first;
     return s;
   }
 
@@ -80,11 +81,11 @@ public:
   }
 
   template <class T>
-  auto expect_at(std::string_view key) -> T
+  auto allow_at(std::string_view key) -> std::optional<T>
   {
     visited_.emplace(key);
     auto const loc = loc_.sub(key);
-    if (auto const jv = obj_.try_at(key))
+    if (auto const jv = obj_.try_at(key); jv && !jv->is_null())
     {
       try
       {
@@ -97,9 +98,22 @@ public:
       }
     }
     else
+    {
+      return std::nullopt;
+    }
+  }
+
+  template <class T>
+  auto expect_at(std::string_view key) -> T
+  {
+    if (auto&& mv = allow_at<T>(key); mv)
+    {
+      return std::forward<T>(*mv);
+    }
+    else
     {
       throw std::runtime_error{std::format(
-          "did not find expected key {}", loc.to_string())};
+          "did not find expected key {}", loc_.sub(key).to_string())};
     }
   }
 };
@@ -124,8 +138,9 @@ auto tag_invoke(
       [](object_reader& r) -> rwgps
       {
         return {
-          .api_key = r.expect_at<std::string>("api_key"),
-          .auth_token = r.expect_at<std::string>("auth_token"),
+          .api_key_filename = r.expect_at<std::string>("api_key_filename"),
+          .auth_token_filename =
+              r.expect_at<std::string>("auth_token_filename"),
         };
       });
 }
@@ -206,7 +221,7 @@ auto json_value_to_app(json::value const& jv) -> app
       [](object_reader& r) -> app
       {
         return {
-          .rwgps = r.expect_at<rwgps>("rwgps"),
+          .rwgps = r.allow_at<rwgps>("rwgps"),
           .situations = r.expect_at<situations>("situations"),
           .database = r.expect_at<database>("database"),
           .http_server = r.expect_at<http_server>("http_server"),
@@ -217,9 +232,12 @@ auto json_value_to_app(json::value const& jv) -> app
 
 auto load_file(std::string const& filename) -> app
 {
-  auto f = std::ifstream{
-    filename
-  }; // TODO: ensure that we are opening in binary mode?
+  // TODO: migrate away from json::value_to w/ tag_invoke.
+  // Boost.JSON does not properly propagate custom exceptions accross
+  // json::value_to calls when certain containers are involved
+  // (std::{optional,variant,vector}).
+
+  auto f = std::ifstream{filename, std::ios::binary};
   if (!f.is_open())
     throw std::runtime_error{std::format("failed to open {}", filename)};
   auto jv = json::value{};
-- 
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