Update network/server type selection code in connect().

- Don't crash when a blank/invalid network is provided (due to throwing
  an uncaught pointer resulting in terminate())
- Remove redundant checks/asserts
- Don't make a full copy of the network JSON or a merge update
- Move "state_dir" hack to session_impl to be shared for spv
- Throw a human readable error if the network is incorrect

Author: jgriffiths

src/network_parameters.cpp

@@ -3,6 +3,7 @@
 #include "assertion.hpp"
 #include "boost_wrapper.hpp"
 #include "containers.hpp"
+#include "exception.hpp"
 #include "network_parameters.hpp"
 
 // TODO: Use std::string_view when its fully supported
@@ -534,7 +535,9 @@ namespace sdk {
         std::unique_lock<std::mutex> l{ registered_networks_mutex };
 
         const auto p = registered_networks.find(name);
-        GDK_RUNTIME_ASSERT_MSG(p != registered_networks.end(), "Unknown network");
+        if (p == registered_networks.end()) {
+            throw user_error("Unknown network");
+        }
         return *p->second;
     }
 

src/session.cpp

@@ -123,43 +123,23 @@ namespace sdk {
     {
         try {
             GDK_RUNTIME_ASSERT_MSG(init_done, "You must call GA_init first");
+            GDK_RUNTIME_ASSERT_MSG(!get_impl(), "session already connected");
 
-            auto impl = get_impl();
-            GDK_RUNTIME_ASSERT_MSG(!impl, "session already connected");
+            const auto network = network_parameters::get(net_params.value("name", std::string()));
+            const auto type = net_params.value("server_type", network.value("server_type", std::string()));
 
             session_ptr session_p;
-            const auto list = ga::sdk::network_parameters::get_all();
-            const auto network_name = net_params.value("name", "");
 
-            if (network_name == "") {
-                GDK_LOG_SEV(log_level::error) << "network name not provided";
-                throw new std::runtime_error("network name not provided");
-            }
-
-            auto network = list.at(network_name);
-
-            if (network == nullptr) {
-                GDK_LOG_SEV(log_level::error) << "network not found: " << network_name;
-                throw new std::runtime_error("network not found");
-            }
-
-            // merge with net_params
-            network.update(net_params.begin(), net_params.end());
-
-            GDK_RUNTIME_ASSERT_MSG(network.contains("server_type"), "server_type field missing");
-            if (network.value("server_type", "") == "green") {
-                session_p = boost::make_shared<ga_session>(network);
+            if (type == "green") {
+                session_p = boost::make_shared<ga_session>(net_params);
 #ifdef BUILD_GDK_RUST
-            } else if (network.value("server_type", "") == "electrum") {
-                GDK_RUNTIME_ASSERT(!gdk_config().at("datadir").empty());
-                network["state_dir"] = std::string(gdk_config().at("datadir")) + "/state";
-                session_p = boost::make_shared<ga_rust>(network);
+            } else if (type == "electrum") {
+                session_p = boost::make_shared<ga_rust>(net_params);
 #endif
             } else {
                 GDK_RUNTIME_ASSERT_MSG(false, "server_type field unknown value");
             }
 
-            GDK_RUNTIME_ASSERT(session_p != nullptr);
             boost::weak_ptr<session_impl> weak_session = session_p;
             session_p->set_ping_fail_handler([weak_session] {
                 if (auto p = weak_session.lock()) {

src/session_impl.cpp

@@ -1,6 +1,7 @@
 #include "session_impl.hpp"
 #include "exception.hpp"
 #include "logging.hpp"
+#include "session.hpp"
 
 namespace ga {
 namespace sdk {
@@ -26,7 +27,10 @@ namespace sdk {
             set_override(ret, "spv_enabled", user_params, false);
             set_override(ret, "use_tor", user_params, false);
             set_override(ret, "user_agent", user_params, std::string());
-
+            // FIXME: Remove this by fetching it directly where needed
+            const std::string datadir = gdk_config().value("datadir", std::string());
+            GDK_RUNTIME_ASSERT(!datadir.empty());
+            ret["state_dir"] = datadir + "/state";
             return network_parameters{ ret };
         }