From d4775552e04dc8ede1e7f1eff07ed87fae64c935 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Wed, 11 Jul 2018 07:01:54 -0500
Subject: [PATCH] Convert Reaction type

---
 CMakeLists.txt   |  1 +
 src/reaction.cpp | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/reaction.h   | 29 +++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 src/reaction.cpp
 create mode 100644 src/reaction.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c2dff6e10..e54c6c367 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -412,6 +412,7 @@ add_library(libopenmc SHARED
   src/position.cpp
   src/pugixml/pugixml_c.cpp
   src/random_lcg.cpp
+  src/reaction.cpp
   src/reaction_product.cpp
   src/secondary_correlated.cpp
   src/secondary_kalbach.cpp
diff --git a/src/reaction.cpp b/src/reaction.cpp
new file mode 100644
index 000000000..7e6a3ae5d
--- /dev/null
+++ b/src/reaction.cpp
@@ -0,0 +1,48 @@
+#include "reaction.h"
+
+#include <string>
+#include <utility> // for move
+
+#include "hdf5_interface.h"
+
+namespace openmc {
+
+Reaction::Reaction(hid_t group, const std::vector<int>& temperatures)
+{
+  read_attribute(group, "Q_value", q_value_);
+  read_attribute(group, "mt", mt_);
+  int cm;
+  read_attribute(group, "center_of_mass", cm);
+  scatter_in_cm_ = (cm == 1);
+
+  // Read cross section and threshold_idx data
+  for (auto t : temperatures) {
+    // Get group corresponding to temperature
+    std::string temp_str {std::to_string(t) + "K"};
+    hid_t temp_group = open_group(group, temp_str.c_str());
+    hid_t dset = open_dataset(temp_group, "xs");
+
+    // Get threshold index
+    TemperatureXS xs;
+    read_attribute(dset, "threshold_idx", xs.threshold);
+
+    // Read cross section values
+    read_dataset(dset, xs.value);
+    close_dataset(dset);
+    close_group(temp_group);
+
+    // create new entry in xs vector
+    xs_.push_back(std::move(xs));
+  }
+
+  // Read products
+  for (const auto& name : group_names(group)) {
+    if (name.rfind("product_", 0) == 0) {
+      hid_t pgroup = open_group(group, name.c_str());
+      products_.emplace_back(pgroup);
+      close_group(pgroup);
+    }
+  }
+}
+
+}
\ No newline at end of file
diff --git a/src/reaction.h b/src/reaction.h
new file mode 100644
index 000000000..0040bd094
--- /dev/null
+++ b/src/reaction.h
@@ -0,0 +1,29 @@
+#ifndef OPENMC_REACTION_H
+#define OPENMC_REACTION_H
+
+#include <vector>
+
+#include "hdf5.h"
+#include "reaction_product.h"
+
+namespace openmc {
+
+class Reaction {
+public:
+  explicit Reaction(hid_t group, const std::vector<int>& temperatures);
+
+  struct TemperatureXS {
+    int threshold;
+    std::vector<double> value;
+  };
+
+  int mt_;             //!< ENDF MT value
+  double q_value_;     //!< Reaction Q value in [eV]
+  bool scatter_in_cm_; //!< scattering system in center-of-mass?
+  std::vector<TemperatureXS> xs_;
+  std::vector<ReactionProduct> products_;
+};
+
+}
+
+#endif // OPENMC_REACTION_H