/* ----------------------------------------------------------------------
   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 "lammps.h"

#include "atom.h"
#include "domain.h"
#include "group.h"
#include "info.h"
#include "input.h"
#include "math_const.h"
#include "region.h"
#include "variable.h"

#include "gmock/gmock.h"
#include "gtest/gtest.h"

#include <cstring>
#include <vector>

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

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

using LAMMPS_NS::MathConst::MY_PI;
using LAMMPS_NS::utils::split_words;

namespace LAMMPS_NS {
using ::testing::ExitedWithCode;
using ::testing::MatchesRegex;
using ::testing::StrEq;

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

class VariableTest : public ::testing::Test {
protected:
    LAMMPS *lmp;
    Group *group;
    Domain *domain;
    Variable *variable;

    void SetUp() override
    {
        const char *args[] = {"VariableTest", "-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);
        if (!verbose) ::testing::internal::GetCapturedStdout();
        group    = lmp->group;
        domain   = lmp->domain;
        variable = lmp->input->variable;
    }

    void TearDown() override
    {
        if (!verbose) ::testing::internal::CaptureStdout();
        delete lmp;
        if (!verbose) ::testing::internal::GetCapturedStdout();
        std::cout.flush();
        unlink("test_variable.file");
        unlink("test_variable.atomfile");
    }

    void command(const std::string &cmd) { lmp->input->one(cmd); }

    void atomic_system()
    {
        if (!verbose) ::testing::internal::CaptureStdout();
        command("units real");
        command("lattice sc 1.0 origin 0.125 0.125 0.125");
        command("region box block -2 2 -2 2 -2 2");
        command("create_box 8 box");
        command("create_atoms 1 box");
        command("mass * 1.0");
        command("region left block -2.0 -1.0 INF INF INF INF");
        command("region right block 0.5  2.0 INF INF INF INF");
        command("region top block INF INF -2.0 -1.0 INF INF");
        command("set region left type 2");
        command("set region right type 3");
        if (!verbose) ::testing::internal::GetCapturedStdout();
    }

    void molecular_system()
    {
        if (!verbose) ::testing::internal::CaptureStdout();
        command("fix props all property/atom mol rmass q");
        if (!verbose) ::testing::internal::GetCapturedStdout();
        atomic_system();
        if (!verbose) ::testing::internal::CaptureStdout();
        command("variable molid atom floor(id/4)+1");
        command("variable charge atom 2.0*sin(PI/32*id)");
        command("set atom * mol v_molid");
        command("set atom * charge v_charge");
        command("set type 1 mass 0.5");
        command("set type 2*4 mass 2.0");
        if (!verbose) ::testing::internal::GetCapturedStdout();
    }

    void file_vars()
    {
        FILE *fp = fopen("test_variable.file", "w");
        fputs("# test file for file style variable\n\n\none\n  two  \n\n"
              "three  # with comment\nfour   ! with non-comment\n"
              "# comments only\n	five\n#END\n",
              fp);
        fclose(fp);
        fp = fopen("test_variable.atomfile", "w");

        fputs("# test file for atomfile style variable\n\n"
              "4  # four lines\n4 0.5   #with comment\n"
              "2 -0.5         \n3 1.5\n1 -1.5\n\n"
              "2\n10 1.0 # test\n13 1.0\n\n######\n"
              "4\n1 4.0 # test\n2 3.0\n3 2.0\n4 1.0\n#END\n",
              fp);
        fclose(fp);
    }
};

TEST_F(VariableTest, CreateDelete)
{
    file_vars();
    ASSERT_EQ(variable->nvar, 0);
    if (!verbose) ::testing::internal::CaptureStdout();
    command("variable one    index     1 2 3 4");
    command("variable two    equal     1");
    command("variable two    equal     2");
    command("variable three  string    four");
    command("variable three  string    three");
    command("variable four1  loop      4");
    command("variable four2  loop      2 4");
    command("variable five1  loop      100 pad");
    command("variable five2  loop      100 200 pad");
    command("variable six    world     one");
    command("variable seven  format    two \"%5.2f\"");
    command("variable eight  getenv    PWD");
    command("variable eight  getenv    HOME");
    command("variable nine   file      test_variable.file");
    command("variable ten    internal  1.0");
    command("variable ten    internal  10.0");
    command("variable ten1   universe  1 2 3 4");
    command("variable ten2   uloop     4");
    command("variable ten3   uloop     4 pad");
    command("variable dummy  index     0");
    if (!verbose) ::testing::internal::GetCapturedStdout();
    ASSERT_EQ(variable->nvar, 16);
    if (!verbose) ::testing::internal::CaptureStdout();
    command("variable dummy  delete");
    if (!verbose) ::testing::internal::GetCapturedStdout();
    ASSERT_EQ(variable->nvar, 15);

    TEST_FAILURE(".*ERROR: Illegal variable command.*", command("variable"););
    TEST_FAILURE(".*ERROR: Illegal variable command.*", command("variable dummy index"););
    TEST_FAILURE(".*ERROR: Illegal variable command.*", command("variable dummy delete xxx"););
    TEST_FAILURE(".*ERROR: Illegal variable command.*", command("variable dummy loop -1"););
    TEST_FAILURE(".*ERROR: Illegal variable command.*", command("variable dummy loop 10 1"););
    TEST_FAILURE(".*ERROR: Cannot redefine variable as a different style.*",
                 command("variable two string xxx"););
    TEST_FAILURE(".*ERROR: Cannot redefine variable as a different style.*",
                 command("variable two getenv xxx"););
    TEST_FAILURE(".*ERROR: Cannot redefine variable as a different style.*",
                 command("variable one equal 2"););
    TEST_FAILURE(".*ERROR: Cannot redefine variable as a different style.*",
                 command("variable one internal 2"););
    TEST_FAILURE(".*ERROR: Cannot use atomfile-style variable unless an atom map exists.*",
                 command("variable eleven    atomfile  test_variable.atomfile"););
    TEST_FAILURE(".*ERROR on proc 0: Cannot open file variable file test_variable.xxx.*",
                 command("variable nine1  file      test_variable.xxx"););
    TEST_FAILURE(".*ERROR: World variable count doesn't match # of partitions.*",
                 command("variable ten10 world xxx xxx"););
    TEST_FAILURE(".*ERROR: All universe/uloop variables must have same # of values.*",
                 command("variable ten4   uloop     2"););
    TEST_FAILURE(".*ERROR: Incorrect conversion in format string.*",
                 command("variable ten11  format    two \"%08f\""););
}

TEST_F(VariableTest, AtomicSystem)
{
    command("atom_modify map array");
    atomic_system();
    file_vars();

    if (!verbose) ::testing::internal::CaptureStdout();
    command("variable  one  index     1 2 3 4");
    command("variable  id   atom      type");
    command("variable  id   atom      id");
    command("variable  ten  atomfile  test_variable.atomfile");
    command("compute   press all pressure NULL pair");
    command("fix       press all ave/time 1 1 1 c_press mode vector");
    command("variable  press  vector   f_press");
    command("variable  stress vector   v_press+vol");
    command("variable  pmax equal   max(f_press)");
    command("run 0 post no");

    if (!verbose) ::testing::internal::GetCapturedStdout();
    ASSERT_EQ(variable->nvar, 6);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_pmax"), 0.0);

    TEST_FAILURE(".*ERROR: Cannot redefine variable as a different style.*",
                 command("variable one atom x"););
    TEST_FAILURE(".*ERROR on proc 0: Cannot open file variable file test_variable.xxx.*",
                 command("variable ten1   atomfile  test_variable.xxx"););
}

TEST_F(VariableTest, Expressions)
{
    atomic_system();
    ASSERT_EQ(variable->nvar, 0);
    if (!verbose) ::testing::internal::CaptureStdout();
    command("variable one    index     1");
    command("variable two    equal     2");
    command("variable three  equal     v_one+v_two");
    command("variable four   equal     PI");
    command("variable five   equal     version");
    command("variable six    equal     XXX");
    command("variable seven  equal     -v_one");
    command("variable eight  equal     v_three-0.5");
    command("variable nine   equal     v_two*(v_one+v_three)");
    command("variable ten    equal     (1.0/v_two)^2");
    command("variable eleven equal     v_three%2");
    command("variable twelve equal     1==2");
    command("variable ten3   equal     1!=v_two");
    command("variable ten4   equal     1<2");
    command("variable ten5   equal     2>1");
    command("variable ten6   equal     (1<=v_one)&&(v_ten>=0.2)");
    command("variable ten7   equal     !(1<v_two)");
    command("variable ten8   equal     1|^0");

    if (!verbose) ::testing::internal::GetCapturedStdout();
    ASSERT_EQ(variable->nvar, 18);

    int ivar = variable->find("one");
    ASSERT_FALSE(variable->equalstyle(ivar));
    ivar = variable->find("two");
    ASSERT_TRUE(variable->equalstyle(ivar));
    ASSERT_DOUBLE_EQ(variable->compute_equal(ivar), 2.0);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_three"), 3.0);
    ASSERT_FLOAT_EQ(variable->compute_equal("v_four"), MY_PI);
    ASSERT_GE(variable->compute_equal("v_five"), 20210310);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_seven"), -1);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_eight"), 2.5);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_nine"), 8);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_ten"), 0.25);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_eleven"), 1);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_twelve"), 0);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_ten3"), 1);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_ten4"), 1);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_ten5"), 1);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_ten6"), 1);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_ten7"), 0);
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_ten8"), 1);

    TEST_FAILURE(".*ERROR: Variable six: Invalid thermo keyword 'XXX' in variable formula.*",
                 command("print \"${six}\""););
}

TEST_F(VariableTest, Functions)
{
    atomic_system();
    file_vars();

    ASSERT_EQ(variable->nvar, 0);
    if (!verbose) ::testing::internal::CaptureStdout();
    command("variable one    index     1");
    command("variable two    equal     random(1,2,643532)");
    command("variable three  equal     atan2(v_one,1)");
    command("variable four   equal     atan2()");
    if (!verbose) ::testing::internal::GetCapturedStdout();
    ASSERT_EQ(variable->nvar, 4);

    int ivar = variable->find("two");
    ASSERT_GT(variable->compute_equal(ivar), 0.99);
    ASSERT_LT(variable->compute_equal(ivar), 2.01);
    ivar = variable->find("three");
    ASSERT_DOUBLE_EQ(variable->compute_equal(ivar), 0.25 * MY_PI);
    TEST_FAILURE(".*ERROR: Variable four: Invalid syntax in variable formula.*",
                 command("print \"${four}\""););
}

TEST_F(VariableTest, IfCommand)
{
    if (!verbose) ::testing::internal::CaptureStdout();
    command("variable one index 1");
    if (!verbose) ::testing::internal::GetCapturedStdout();

    ::testing::internal::CaptureStdout();
    command("if 1>0 then 'print \"bingo!\"'");
    auto text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    ::testing::internal::CaptureStdout();
    command("if 1>2 then 'print \"bingo!\"' else 'print \"nope?\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*nope\?.*"));

    ::testing::internal::CaptureStdout();
    command("if (1<=0) then 'print \"bingo!\"' else 'print \"nope?\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*nope\?.*"));

    ::testing::internal::CaptureStdout();
    command("if (-1.0e-1<0.0E+0)|^(1<0) then 'print \"bingo!\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    ::testing::internal::CaptureStdout();
    command("if (${one}==1.0)&&(2>=1) then 'print \"bingo!\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    ::testing::internal::CaptureStdout();
    command("if !((${one}!=1.0)||(2|^1)) then 'print \"missed\"' else 'print \"bingo!\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    ::testing::internal::CaptureStdout();
    command("if (1>=2)&&(0&&1) then 'print \"missed\"' else 'print \"bingo!\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    ::testing::internal::CaptureStdout();
    command("if !1 then 'print \"missed\"' else 'print \"bingo!\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    ::testing::internal::CaptureStdout();
    command("if !(a==b) then 'print \"bingo!\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    ::testing::internal::CaptureStdout();
    command("if x==x|^1==0 then 'print \"bingo!\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    ::testing::internal::CaptureStdout();
    command("if x!=x|^a!=b then 'print \"bingo!\"'");
    text = ::testing::internal::GetCapturedStdout();
    if (verbose) std::cout << text;
    ASSERT_THAT(text, MatchesRegex(".*bingo!.*"));

    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if () then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if \"1 1\" then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if 1a then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if 1=<2 then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if 1!=a then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if 1&<2 then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if 1|<2 then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if (1)( then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if (1)1 then 'print \"bingo!\"'"););
    TEST_FAILURE(".*ERROR: Invalid Boolean syntax in if command.*",
                 command("if (v_one==1.0)&&(2>=1) then 'print \"bingo!\"'"););
}

TEST_F(VariableTest, NextCommand)
{
    file_vars();

    if (!verbose) ::testing::internal::CaptureStdout();
    command("variable one    index  1 2");
    command("variable two    equal  2");
    command("variable three  file   test_variable.file");
    command("variable four   loop   2 4");
    command("variable five   index  1 2");
    if (!verbose) ::testing::internal::GetCapturedStdout();
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_one"), 1);
    ASSERT_THAT(variable->retrieve("three"), StrEq("one"));
    if (!verbose) ::testing::internal::CaptureStdout();
    command("next one");
    command("next three");
    if (!verbose) ::testing::internal::GetCapturedStdout();
    ASSERT_DOUBLE_EQ(variable->compute_equal("v_one"), 2);
    ASSERT_THAT(variable->retrieve("three"), StrEq("two"));
    ASSERT_GE(variable->find("one"), 0);
    if (!verbose) ::testing::internal::CaptureStdout();
    command("next one");
    command("next three");
    if (!verbose) ::testing::internal::GetCapturedStdout();
    // index style variable is deleted if no more next element
    ASSERT_EQ(variable->find("one"), -1);
    ASSERT_GE(variable->find("three"), 0);
    if (!verbose) ::testing::internal::CaptureStdout();
    command("next three");
    command("next three");
    command("next three");
    if (!verbose) ::testing::internal::GetCapturedStdout();
    // file style variable is deleted if no more next element
    ASSERT_EQ(variable->find("three"), -1);

    TEST_FAILURE(".*ERROR: Illegal next command.*", command("next"););
    TEST_FAILURE(".*ERROR: Invalid variable 'xxx' in next command.*", command("next xxx"););
    TEST_FAILURE(".*ERROR: Invalid variable style with next command.*", command("next two"););
    TEST_FAILURE(".*ERROR: All variables in next command must have same style.*",
                 command("next five four"););
}
} // namespace LAMMPS_NS

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;
}