From 946b5f5806b89539050b75547b638a4f47e3afe9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?H=C3=A5kon=20H=C3=A6gland?= <hakon.hagland@gmail.com>
Date: Mon, 11 May 2020 17:57:43 +0200
Subject: [PATCH] Refactor flow_ebos_blackoil.cpp (2)

NOTE: this pull request depends on #2555 which should be merged first.

A rewrite of the outdated PR #2543.

Refactors flow_ebos_blackoil.cpp such that we can choose not to execute
the whole simulation using the flowEbosBlackoilMain() function but
instead only initialize by calling flowEbosBlackoilMainInit(). This is
necessary to implement a Python step() method that can advance the
simulator one report step at a time.

Also adds a method initFlowEbosBlackoil() to Main.hpp that can be used
directly from the Python interface's BlackOilSimulator object to gain
access to the FlowMainEbos object before it has initialized the
simulation main loop.
---
 flow/flow_ebos_blackoil.cpp  | 14 ++++++++++----
 flow/flow_ebos_blackoil.hpp  |  5 +++++
 opm/simulators/flow/Main.hpp | 25 +++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/flow/flow_ebos_blackoil.cpp b/flow/flow_ebos_blackoil.cpp
index 809610682..e02595ba2 100644
--- a/flow/flow_ebos_blackoil.cpp
+++ b/flow/flow_ebos_blackoil.cpp
@@ -46,8 +46,8 @@ void flowEbosBlackoilSetDeck(double setupTime, Deck *deck, EclipseState& eclStat
     Vanguard::setExternalSummaryConfig(&summaryConfig);
 }
 
-// ----------------- Main program -----------------
-int flowEbosBlackoilMain(int argc, char** argv, bool outputCout, bool outputFiles)
+std::unique_ptr<Opm::FlowMainEbos<TTAG(EclFlowProblem)>>
+flowEbosBlackoilMainInit(int argc, char** argv, bool outputCout, bool outputFiles)
 {
     // we always want to use the default locale, and thus spare us the trouble
     // with incorrect locale settings.
@@ -59,8 +59,14 @@ int flowEbosBlackoilMain(int argc, char** argv, bool outputCout, bool outputFile
     Dune::MPIHelper::instance(argc, argv);
 #endif
 
-    Opm::FlowMainEbos<TTAG(EclFlowProblem)> mainfunc;
-    return mainfunc.execute(argc, argv, outputCout, outputFiles);
+    return std::make_unique<Opm::FlowMainEbos<TTAG(EclFlowProblem)>>();
+}
+
+// ----------------- Main program -----------------
+int flowEbosBlackoilMain(int argc, char** argv, bool outputCout, bool outputFiles)
+{
+    auto mainfunc = flowEbosBlackoilMainInit(argc, argv, outputCout, outputFiles);
+    return mainfunc->execute(argc, argv, outputCout, outputFiles);
 }
 
 }
diff --git a/flow/flow_ebos_blackoil.hpp b/flow/flow_ebos_blackoil.hpp
index 641d74aa2..3ca378919 100644
--- a/flow/flow_ebos_blackoil.hpp
+++ b/flow/flow_ebos_blackoil.hpp
@@ -21,10 +21,15 @@
 #include <opm/parser/eclipse/EclipseState/EclipseState.hpp>
 #include <opm/parser/eclipse/EclipseState/Schedule/Schedule.hpp>
 #include <opm/parser/eclipse/EclipseState/SummaryConfig/SummaryConfig.hpp>
+#include <opm/simulators/flow/FlowMainEbos.hpp>
 
 namespace Opm {
 void flowEbosBlackoilSetDeck(double setupTime, Deck *deck, EclipseState& eclState, Schedule& schedule, SummaryConfig& summaryConfig);
+
 int flowEbosBlackoilMain(int argc, char** argv, bool outputCout, bool outputFiles);
+
+std::unique_ptr<Opm::FlowMainEbos<TTAG(EclFlowProblem)>>
+    flowEbosBlackoilMainInit(int argc, char** argv, bool outputCout, bool outputFiles);
 }
 
 #endif // FLOW_EBOS_BLACKOIL_HPP
diff --git a/opm/simulators/flow/Main.hpp b/opm/simulators/flow/Main.hpp
index 10815af73..1e7814fc6 100644
--- a/opm/simulators/flow/Main.hpp
+++ b/opm/simulators/flow/Main.hpp
@@ -117,6 +117,7 @@ namespace Opm
     class Main
     {
     private:
+        using FlowMainEbosType = Opm::FlowMainEbos<TTAG(EclFlowProblem)>;
         enum class FileOutputMode {
             //! \brief No output to files.
             OUTPUT_NONE = 0,
@@ -174,6 +175,30 @@ namespace Opm
             }
         }
 
+        // To be called from the Python interface code. Only do the
+        // initialization and then return a pointer to the FlowEbosMain
+        // object that can later be accessed directly from the Python interface
+        // to e.g. advance the simulator one report step
+        std::unique_ptr<FlowMainEbosType> initFlowEbosBlackoil(int& exitCode)
+        {
+            exitCode = EXIT_SUCCESS;
+            if (initialize_<TTAG(FlowEarlyBird)>(exitCode)) {
+                // TODO: check that this deck really represents a blackoil
+                // case. E.g. check that number of phases == 3
+                Opm::flowEbosBlackoilSetDeck(
+                    setupTime_,
+                    deck_.get(),
+                    *eclipseState_,
+                    *schedule_,
+                    *summaryConfig_);
+                return Opm::flowEbosBlackoilMainInit(
+                    argc_, argv_, outputCout_, outputFiles_);
+            } else {
+                exitCode = EXIT_FAILURE;
+                return std::unique_ptr<FlowMainEbosType>(); // nullptr
+            }
+        }
+
     private:
         int dispatchDynamic_()
         {