// @HEADER
// *****************************************************************************
//               Rapid Optimization Library (ROL) Package
//
// Copyright 2014 NTESS and the ROL contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER

/*! \file  example_01.cpp
    \brief Shows how to solve the Navier-Stokes control problem.
*/

#include "Teuchos_Comm.hpp"
#include "ROL_Stream.hpp"
#include "ROL_GlobalMPISession.hpp"

#include "Tpetra_Core.hpp"
#include "Tpetra_Version.hpp"

#include <iostream>
#include <algorithm>
//#include <fenv.h>

#include "ROL_TpetraMultiVector.hpp"
#include "ROL_Reduced_Objective_SimOpt.hpp"
#include "ROL_Solver.hpp"

#include "../TOOLS/meshmanagerK.hpp"
#include "../TOOLS/pdeconstraintK.hpp"
#include "../TOOLS/pdeobjectiveK.hpp"
#include "../TOOLS/pdevectorK.hpp"
#include "pde_thermal-fluidsK.hpp"
#include "obj_thermal-fluidsK.hpp"

using RealT = double;
using DeviceT = Kokkos::HostSpace;

int main(int argc, char *argv[]) {
  //feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW);

  // This little trick lets us print to std::cout only if a (dummy) command-line argument is provided.
  int iprint     = argc - 1;
  ROL::Ptr<std::ostream> outStream;
  ROL::nullstream bhs; // outputs nothing

  /*** Initialize communicator. ***/
  ROL::GlobalMPISession mpiSession (&argc, &argv, &bhs);
  Kokkos::ScopeGuard kokkosScope (argc, argv);
  auto comm = Tpetra::getDefaultComm();
  const int myRank = comm->getRank();
  if ((iprint > 0) && (myRank == 0))
    outStream = ROL::makePtrFromRef(std::cout);
  else
    outStream = ROL::makePtrFromRef(bhs);
  int errorFlag  = 0;

  // *** Example body.
  try {

    /*** Read in XML input ***/
    std::string filename = "input.xml";
    auto parlist = ROL::getParametersFromXmlFile(filename);

    /*** Initialize main data structure. ***/
    auto meshMgr = ROL::makePtr<MeshManager_BackwardFacingStepChannel<RealT,DeviceT>>(*parlist);
    // Initialize PDE describing Navier-Stokes equations.
    auto pde = ROL::makePtr<PDE_ThermalFluids<RealT,DeviceT>>(*parlist);
    auto con = ROL::makePtr<PDE_Constraint<RealT,DeviceT>>(pde,meshMgr,comm,*parlist,*outStream);
    // Cast the constraint and get the assembler.
    auto assembler = con->getAssembler();
    con->setSolveParameters(*parlist);
    con->outputTpetraData();

    // Create state vector and set to zeroes
    auto u_ptr  = assembler->createStateVector();     u_ptr->randomize();
    auto p_ptr  = assembler->createStateVector();     p_ptr->randomize();
    auto du_ptr = assembler->createStateVector();     du_ptr->randomize();
    auto r_ptr  = assembler->createResidualVector();  r_ptr->randomize();
    auto z_ptr  = assembler->createControlVector();   z_ptr->randomize();
    auto dz_ptr = assembler->createControlVector();   dz_ptr->randomize();
    auto up  = ROL::makePtr<PDE_PrimalSimVector<RealT,DeviceT>>(u_ptr,pde,assembler);
    auto pp  = ROL::makePtr<PDE_PrimalSimVector<RealT,DeviceT>>(p_ptr,pde,assembler);
    auto dup = ROL::makePtr<PDE_PrimalSimVector<RealT,DeviceT>>(du_ptr,pde,assembler);
    auto rp  = ROL::makePtr<PDE_DualSimVector<RealT,DeviceT>>(r_ptr,pde,assembler);
    auto zp  = ROL::makePtr<PDE_PrimalOptVector<RealT,DeviceT>>(z_ptr,pde,assembler);
    auto dzp = ROL::makePtr<PDE_PrimalOptVector<RealT,DeviceT>>(dz_ptr,pde,assembler);
    // Create ROL SimOpt vectors
    ROL::Vector_SimOpt<RealT> x(up,zp);
    ROL::Vector_SimOpt<RealT> d(dup,dzp);

    // Initialize objective function.
    std::vector<ROL::Ptr<QoI<RealT,DeviceT>>> qoi_vec(2,ROL::nullPtr);
    qoi_vec[0] = ROL::makePtr<QoI_State_ThermalFluids<RealT,DeviceT>>(*parlist,
                                                                 pde->getVelocityFE(),
                                                                 pde->getPressureFE(),
                                                                 pde->getThermalFE(),
                                                                 pde->getFieldHelper());
    qoi_vec[1] = ROL::makePtr<QoI_L2Penalty_ThermalFluids<RealT,DeviceT>>(pde->getVelocityFE(),
                                                                     pde->getPressureFE(),
                                                                     pde->getThermalFE(),
                                                                     pde->getThermalBdryFE(),
                                                                     pde->getBdryCellLocIds(),
                                                                     pde->getFieldHelper());
    auto std_obj = ROL::makePtr<StdObjective_ThermalFluids<RealT>>(*parlist);
    auto obj = ROL::makePtr<PDE_Objective<RealT,DeviceT>>(qoi_vec,std_obj,assembler);
    auto stateStore = ROL::makePtr<ROL::VectorController<RealT>>();
    auto robj = ROL::makePtr<ROL::Reduced_Objective_SimOpt<RealT>>(obj, con, stateStore, up, zp, pp, true, false);

    // Run derivative checks
    bool checkDeriv = parlist->sublist("Problem").get("Check derivatives",false);
    if ( checkDeriv ) {
      *outStream << "Check Gradient of Full Objective Function" << std::endl;
      obj->checkGradient(x,d,true,*outStream);
      *outStream << std::endl << "Check Hessian of Full Objective Function" << std::endl;
      obj->checkHessVec(x,d,true,*outStream);
      *outStream << std::endl << "Check Jacobian of Constraint" << std::endl;
      con->checkApplyJacobian(x,d,*up,true,*outStream);
      *outStream << std::endl << "Check Jacobian_1 of Constraint" << std::endl;
      con->checkApplyJacobian_1(*up,*zp,*dup,*rp,true,*outStream);
      *outStream << std::endl << "Check Jacobian_2 of Constraint" << std::endl;
      con->checkApplyJacobian_2(*up,*zp,*dzp,*rp,true,*outStream);
      *outStream << std::endl << "Check Hessian of Constraint" << std::endl;
      con->checkApplyAdjointHessian(x,*dup,d,x,true,*outStream);
      *outStream << std::endl << "Check Hessian_11 of Constraint" << std::endl;
      con->checkApplyAdjointHessian_11(*up,*zp,*pp,*dup,*rp,true,*outStream);
      *outStream << std::endl << "Check Hessian_12 of Constraint" << std::endl;
      con->checkApplyAdjointHessian_12(*up,*zp,*pp,*dup,*dzp,true,*outStream);
      *outStream << std::endl << "Check Hessian_21 of Constraint" << std::endl;
      con->checkApplyAdjointHessian_21(*up,*zp,*pp,*dzp,*rp,true,*outStream);
      *outStream << std::endl << "Check Hessian_22 of Constraint" << std::endl;
      con->checkApplyAdjointHessian_22(*up,*zp,*pp,*dzp,*dzp,true,*outStream);

      *outStream << std::endl << "Check Adjoint Jacobian of Constraint" << std::endl;
      con->checkAdjointConsistencyJacobian(*dup,d,x,true,*outStream);
      *outStream << std::endl << "Check Adjoint Jacobian_1 of Constraint" << std::endl;
      con->checkAdjointConsistencyJacobian_1(*pp,*dup,*up,*zp,true,*outStream);
      *outStream << std::endl << "Check Adjoint Jacobian_2 of Constraint" << std::endl;
      con->checkAdjointConsistencyJacobian_2(*pp,*dzp,*up,*zp,true,*outStream);

      *outStream << std::endl << "Check Constraint Solve" << std::endl;
      con->checkSolve(*up,*zp,*rp,true,*outStream);
      *outStream << std::endl << "Check Inverse Jacobian_1 of Constraint" << std::endl;
      con->checkInverseJacobian_1(*rp,*dup,*up,*zp,true,*outStream);
      *outStream << std::endl << "Check Inverse Adjoint Jacobian_1 of Constraint" << std::endl;
      con->checkInverseAdjointJacobian_1(*rp,*pp,*up,*zp,true,*outStream);

      *outStream << std::endl << "Check Gradient of Reduced Objective Function" << std::endl;
      robj->checkGradient(*zp,*dzp,true,*outStream);
      *outStream << std::endl << "Check Hessian of Reduced Objective Function" << std::endl;
      robj->checkHessVec(*zp,*dzp,true,*outStream);
    }
    up->zero();
    zp->zero();

    RealT tol(1.e-8);
    con->solve(*rp,*up,*zp,tol);
    con->outputTpetraVector(u_ptr,"state_uncontrolled.txt");

    ROL::Ptr<ROL::Problem<RealT>> problem;
    bool useFullSpace = parlist->sublist("Problem").get("Full space",false);
    if ( useFullSpace ) {
      problem = ROL::makePtr<ROL::Problem<RealT>>(obj, ROL::makePtrFromRef(x));
      problem->addConstraint("PDE", con, rp);
    }
    else {
      problem = ROL::makePtr<ROL::Problem<RealT>>(robj, zp);
    }
    problem->finalize(false,true,*outStream);
    ROL::Solver<RealT> solver(problem, *parlist);
    solver.solve(*outStream);

    // Output.
    assembler->printMeshData(*outStream);
    Teuchos::Array<RealT> res(1,0);
    con->solve(*rp,*up,*zp,tol);
    con->outputTpetraVector(u_ptr,"state.txt");
    con->outputTpetraVector(z_ptr,"control.txt");
    con->value(*rp,*up,*zp,tol);
    r_ptr->norm2(res.view(0,1));
    *outStream << "Residual Norm: " << res[0] << std::endl;
    errorFlag += (res[0] > 1.e-6 ? 1 : 0);
    //con->outputTpetraData();

    auto obj0 = ROL::makePtr<IntegralObjective<RealT,DeviceT>>(qoi_vec[0],assembler);
    RealT val = obj0->value(*up,*zp,tol);
    *outStream << "Vorticity Value: " << val << std::endl;
  }
  catch (std::logic_error& err) {
    *outStream << err.what() << "\n";
    errorFlag = -1000;
  }; // end try

  if (errorFlag != 0)
    std::cout << "End Result: TEST FAILED\n";
  else
    std::cout << "End Result: TEST PASSED\n";

  return 0;
}
