#include "state_merge.h"

#include "safepower_agent.pb.h"
#include "google/protobuf/map.h"

namespace safepower_agent {

using ::safepower_agent_proto::SystemState;
using ::safepower_agent_proto::NodeState;

static void Update(google::protobuf::Message& dest, const google::protobuf::Message& update) {
  dest.MergeFrom(update);
}

// NodeState contains a map field, so we need to handle it separately.
static void Update(NodeState& dest, const NodeState& update);

// Recursively update a map field.
template <typename Key, typename Value>
static void Update(google::protobuf::Map<Key, Value>& dest,
                   const google::protobuf::Map<Key, Value>& update) {
  for (const auto& [key, value] : update) {
    auto found = dest.find(key);
    if (found == dest.end()) {
      dest.insert({key, value});
    } else {
      Update(found->second, value);
    }
  }
}

static void Update(NodeState& dest, const NodeState& update) {
  Update(*dest.mutable_component_state(), update.component_state());
}

template <>
void ApplyStateUpdate(SystemState& current_state, const SystemState& update) {
  if (update.has_epoch_ms()) {
    current_state.set_epoch_ms(update.epoch_ms());
  }
  Update(*current_state.mutable_node_state(), update.node_state());
}


}  // namespace safepower_agent