/* ----------------------------------------------------------------------
   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
   https://lammps.sandia.gov/, Sandia National Laboratories
   Steve Plimpton, sjplimp@sandia.gov

   Copyright (2003) Sandia Corporation.  Under the terms of Contract
   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
   certain rights in this software.  This software is distributed under
   the GNU General Public License.

   See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */

#include "info.h"
#include "input.h"
#include "lammps.h"
#include "molecule.h"
#include "utils.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

#include <cstdio>
#include <mpi.h>
#include <string>

using namespace LAMMPS_NS;

using testing::MatchesRegex;
using testing::StrEq;

using utils::split_words;

#define test_name test_info_->name()

#if defined(OMPI_MAJOR_VERSION)
const bool have_openmpi = true;
#else
const bool have_openmpi = false;
#endif

#define TEST_FAILURE(errmsg, ...)                                 \
    if (Info::has_exceptions()) {                                 \
        ::testing::internal::CaptureStdout();                     \
        ASSERT_ANY_THROW({__VA_ARGS__});                          \
        auto mesg = ::testing::internal::GetCapturedStdout();     \
        ASSERT_THAT(mesg, MatchesRegex(errmsg));                  \
    } else {                                                      \
        if (!have_openmpi) {                                      \
            ::testing::internal::CaptureStdout();                 \
            ASSERT_DEATH({__VA_ARGS__}, "");                      \
            auto mesg = ::testing::internal::GetCapturedStdout(); \
            ASSERT_THAT(mesg, MatchesRegex(errmsg));              \
        }                                                         \
    }

static void create_molecule_files()
{
    // create molecule files
    const char h2o_file[] = "# Water molecule. SPC/E model.\n\n3 atoms\n2 bonds\n1 angles\n\n"
                            "Coords\n\n1 1.12456 0.09298 1.27452\n"
                            "2 1.53683 0.75606 1.89928\n3 0.49482 0.56390 0.65678\n\n"
                            "Types\n\n1 1\n2 2\n3 2\n\n"
                            "Charges\n\n1 -0.8472\n2 0.4236\n3 0.4236\n\n"
                            "Bonds\n\n1 1 1 2\n2 1 1 3\n\n"
                            "Angles\n\n1 1 2 1 3\n\n"
                            "Shake Flags\n\n1 1\n2 1\n3 1\n\n"
                            "Shake Atoms\n\n1 1 2 3\n2 1 2 3\n3 1 2 3\n\n"
                            "Shake Bond Types\n\n1 1 1 1\n2 1 1 1\n3 1 1 1\n\n"
                            "Special Bond Counts\n\n1 2 0 0\n2 1 1 0\n3 1 1 0\n\n"
                            "Special Bonds\n\n1 2 3\n2 1 3\n3 1 2\n\n";
    const char co2_file[] = "# CO2 molecule file. TraPPE model.\n\n"
                            "3 atoms\n2 bonds\n1 angles\n\n"
                            "Coords\n\n1 0.0 0.0 0.0\n2 -1.16 0.0 0.0\n3 1.16 0.0 0.0\n\n"
                            "Types\n\n1 1\n2 2\n3 2\n\n"
                            "Charges\n\n1 0.7\n2 -0.35\n3 -0.35\n\n"
                            "Bonds\n\n1 1 1 2\n2 1 1 3\n\n"
                            "Angles\n\n1 1 2 1 3\n\n"
                            "Special Bond Counts\n\n1 2 0 0\n2 1 1 0\n3 1 1 0\n\n"
                            "Special Bonds\n\n1 2 3\n2 1 3\n3 1 2\n\n";

    FILE *fp = fopen("tmp.h2o.mol", "w");
    if (fp) {
        fputs(h2o_file, fp);
        fclose(fp);
    }
    rename("tmp.h2o.mol", "h2o.mol");
    fp = fopen("tmp.co2.mol", "w");
    if (fp) {
        fputs(co2_file, fp);
        fclose(fp);
    }
    rename("tmp.co2.mol", "co2.mol");
}

// whether to print verbose output (i.e. not capturing LAMMPS screen output).
bool verbose = false;

class MoleculeFileTest : public ::testing::Test {
protected:
    LAMMPS *lmp;

    void SetUp() override
    {
        const char *args[] = {"MoleculeFileTest", "-log", "none", "-echo", "screen", "-nocite"};
        char **argv        = (char **)args;
        int argc           = sizeof(args) / sizeof(char *);
        if (!verbose) ::testing::internal::CaptureStdout();
        lmp = new LAMMPS(argc, argv, MPI_COMM_WORLD);
        create_molecule_files();
        if (!verbose) ::testing::internal::GetCapturedStdout();
        ASSERT_NE(lmp, nullptr);
    }

    void TearDown() override
    {
        if (!verbose) ::testing::internal::CaptureStdout();
        delete lmp;
        if (!verbose) ::testing::internal::GetCapturedStdout();
        remove("h2o.mol");
        remove("co2.mol");
    }

    void run_mol_cmd(const std::string &name, const std::string &args, const std::string &content)
    {
        std::string file = name + ".mol";
        FILE *fp = fopen(file.c_str(), "w");
        fputs(content.c_str(),fp);
        fclose(fp);

        lmp->input->one(fmt::format("molecule {} {} {}",name,file,args));
        remove(file.c_str());
    }       
};

TEST_F(MoleculeFileTest, nofile)
{
    TEST_FAILURE(".*Cannot open molecule file nofile.mol.*",
                 lmp->input->one("molecule 1 nofile.mol"););
}

TEST_F(MoleculeFileTest, badid)
{
    TEST_FAILURE(".*Molecule template ID must have only "
                 "alphanumeric or underscore characters.*",
                 lmp->input->one("molecule @mol nofile.mol"););
}

TEST_F(MoleculeFileTest, badargs)
{
    TEST_FAILURE(".*Illegal molecule command.*",
                 run_mol_cmd(test_name,"offset 1 2 3 4",
                             "Comment\n1 atoms\n\n Coords\n\n 1 0.0 0.0 0.0\n"););
    TEST_FAILURE(".*Illegal molecule command.*",
                 run_mol_cmd(test_name,"toff",
                             "Comment\n1 atoms\n\n Coords\n\n 1 0.0 0.0 0.0\n"););
    TEST_FAILURE(".*Illegal molecule command.*",
                 run_mol_cmd(test_name,"boff",
                             "Comment\n1 atoms\n\n Coords\n\n 1 0.0 0.0 0.0\n"););
    TEST_FAILURE(".*Illegal molecule command.*",
                 run_mol_cmd(test_name,"aoff",
                             "Comment\n1 atoms\n\n Coords\n\n 1 0.0 0.0 0.0\n"););
    TEST_FAILURE(".*Illegal molecule command.*",
                 run_mol_cmd(test_name,"doff",
                             "Comment\n1 atoms\n\n Coords\n\n 1 0.0 0.0 0.0\n"););
    TEST_FAILURE(".*Illegal molecule command.*",
                 run_mol_cmd(test_name,"ioff",
                             "Comment\n1 atoms\n\n Coords\n\n 1 0.0 0.0 0.0\n"););
    TEST_FAILURE(".*Illegal molecule command.*",
                 run_mol_cmd(test_name,"scale",
                             "Comment\n1 atoms\n\n Coords\n\n 1 0.0 0.0 0.0\n"););
    remove("badargs.mol");
}

TEST_F(MoleculeFileTest, noatom)
{
    TEST_FAILURE(".*ERROR: No atoms or invalid atom count in molecule file.*",
                 run_mol_cmd(test_name,"","Comment\n0 atoms\n1 bonds\n\n"
                                    " Coords\n\nBonds\n\n 1 1 2\n"););
    remove("noatom.mol");
}

TEST_F(MoleculeFileTest, empty)
{
    TEST_FAILURE(".*ERROR: Unexpected end of molecule file.*",
                 run_mol_cmd(test_name,"","Comment\n\n"););
    remove("empty.mol");
}

TEST_F(MoleculeFileTest, nospecial)
{
    TEST_FAILURE(".*ERROR: Cannot auto-generate special bonds before simulation box is defined.*",
                 run_mol_cmd(test_name,"","Comment\n3 atoms\n\n2 bonds\n\n"
                             " Coords\n\n 1 1.0 1.0 1.0\n 2 1.0 1.0 0.0\n 3 1.0 0.0 1.0\n"
                             " Bonds\n\n 1 1 1 2\n 2 1 1 3\n"););
    remove("nospecial.mol");
}

TEST_F(MoleculeFileTest, minimal)
{
    ::testing::internal::CaptureStdout();
    run_mol_cmd(test_name,"","Comment\n1 atoms\n\n Coords\n\n 1 0.0 0.0 0.0\n");
    auto output = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << output;
    ASSERT_THAT(output,MatchesRegex(".*Read molecule template.*1 molecules.*1 atoms.*0 bonds.*"));
}

TEST_F(MoleculeFileTest, twomols)
{
    ::testing::internal::CaptureStdout();
    run_mol_cmd(test_name,"","Comment\n2 atoms\n\n"
                " Coords\n\n 1 0.0 0.0 0.0\n 2 0.0 0.0 1.0\n"
                " Molecules\n\n 1 1\n 2 2\n\n Types\n\n 1 1\n 2 2\n\n");
    auto output = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << output;
    ASSERT_THAT(output,MatchesRegex(".*Read molecule template.*2 molecules.*2 atoms "
                                    "with max type 2.*0 bonds.*"));
}

TEST_F(MoleculeFileTest, twofiles)
{
    ::testing::internal::CaptureStdout();
    lmp->input->one("molecule twomols h2o.mol co2.mol offset 2 1 1 0 0");
    auto output = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << output;
    ASSERT_THAT(output,MatchesRegex(".*Read molecule template twomols:.*1 molecules.*3 atoms "
                                    "with max type 2.*2 bonds with max type 1.*"
                                    "1 angles with max type 1.*0 dihedrals.*"
                                    ".*Read molecule template twomols:.*1 molecules.*3 atoms "
                                    "with max type 4.*2 bonds with max type 2.*"
                                    "1 angles with max type 2.*0 dihedrals.*"));
}

TEST_F(MoleculeFileTest, bonds)
{
    ::testing::internal::CaptureStdout();
    lmp->input->one("atom_style bond");
    lmp->input->one("region box block 0 1 0 1 0 1");
    lmp->input->one("create_box 2 box bond/types 2 extra/bond/per/atom 2 "
                    "extra/special/per/atom 4");
    run_mol_cmd(test_name,"","Comment\n"
                "4 atoms\n"
                "2 bonds\n\n"
                " Coords\n\n"
                " 1 1.0 1.0 1.0\n"
                " 2 1.0 1.0 0.0\n"
                " 3 1.0 0.0 1.0\n"
                " 4 1.0 0.0 0.0\n"
                " Types\n\n"
                " 1 1\n"
                " 2 1\n"
                " 3 2\n"
                " 4 2\n\n"
                " Bonds\n\n"
                " 1 1 1 2\n"
                " 2 2 1 3\n\n");
    auto output = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << output;
    ASSERT_THAT(output,MatchesRegex(".*Read molecule template.*1 molecules.*4 atoms.*type.*2.*"
                                    "2 bonds.*type.*2.*0 angles.*"));

    ::testing::internal::CaptureStdout();
    lmp->input->one("create_atoms 0 single 0.0 0.0 0.0 mol bonds 67235");
    output = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << output;
    ASSERT_THAT(output,MatchesRegex(".*Created 4 atoms.*"));
}

int main(int argc, char **argv)
{
    MPI_Init(&argc, &argv);
    ::testing::InitGoogleMock(&argc, argv);

    if (have_openmpi && !LAMMPS_NS::Info::has_exceptions())
        std::cout << "Warning: using OpenMPI without exceptions. "
                     "Death tests will be skipped\n";

    // handle arguments passed via environment variable
    if (const char *var = getenv("TEST_ARGS")) {
        std::vector<std::string> env = split_words(var);
        for (auto arg : env) {
            if (arg == "-v") {
                verbose = true;
            }
        }
    }

    if ((argc > 1) && (strcmp(argv[1], "-v") == 0)) verbose = true;

    int rv = RUN_ALL_TESTS();
    MPI_Finalize();
    return rv;
}