// unit tests for issuing command to a LAMMPS instance through the library interface

#include "library.h"
#include "lammps.h"
#include <string>

#include "gtest/gtest.h"

const char *demo_input[] = {
      "region       box block 0 $x 0 2 0 2",
      "create_box 1 box",
      "create_atoms 1 single 1.0 1.0 ${zpos}" };
const char *cont_input[] = {
    "create_atoms 1 single &",
    "0.2 0.1 0.1" };

class LAMMPS_commands : public ::testing::Test
{
protected:
    void *lmp;
    LAMMPS_commands() {};
    ~LAMMPS_commands() override {};

    void SetUp() override {
        const char *args[] = {"LAMMPS_test",
                              "-log", "none",
                              "-echo", "screen",
                              "-nocite", "-var","x","2",
                              "-var", "zpos", "1.5"};
        char **argv = (char **)args;
        int argc = sizeof(args)/sizeof(char *);

        ::testing::internal::CaptureStdout();
        lmp = lammps_open_no_mpi(argc, argv, NULL);
        std::string output = ::testing::internal::GetCapturedStdout();
        EXPECT_STREQ(output.substr(0,8).c_str(), "LAMMPS (");
    }
    void TearDown() override {
        ::testing::internal::CaptureStdout();
        lammps_close(lmp);
        std::string output = ::testing::internal::GetCapturedStdout();
        EXPECT_STREQ(output.substr(0,16).c_str(), "Total wall time:");
        lmp = nullptr;
    }
};

TEST_F(LAMMPS_commands, from_file) {
    FILE *fp;
    const char demo_file[] = "in.test";
    const char cont_file[] = "in.cont";

    fp = fopen(demo_file,"w");
    for (unsigned int i=0; i < sizeof(demo_input)/sizeof(char *); ++i) {
        fputs(demo_input[i],fp);
        fputc('\n',fp);
    }
    fclose(fp);
    fp = fopen(cont_file,"w");
    for (unsigned int i=0; i < sizeof(cont_input)/sizeof(char *); ++i) {
        fputs(cont_input[i],fp);
        fputc('\n',fp);
    }
    fclose(fp);

    EXPECT_EQ(lammps_get_natoms(lmp),0);
    lammps_file(lmp,demo_file);
    lammps_file(lmp,cont_file);
    EXPECT_EQ(lammps_get_natoms(lmp),2);

    unlink(demo_file);
    unlink(cont_file);
};

TEST_F(LAMMPS_commands, from_line) {
    EXPECT_EQ(lammps_get_natoms(lmp),0);
    for (unsigned int i=0; i < sizeof(demo_input)/sizeof(char *); ++i) {
        lammps_command(lmp,demo_input[i]);
    }
    EXPECT_EQ(lammps_get_natoms(lmp),1);
};

TEST_F(LAMMPS_commands, from_list) {
    EXPECT_EQ(lammps_get_natoms(lmp),0);
    lammps_commands_list(lmp,sizeof(demo_input)/sizeof(char *),demo_input);
    lammps_commands_list(lmp,sizeof(cont_input)/sizeof(char *),cont_input);
    EXPECT_EQ(lammps_get_natoms(lmp),2);
};

TEST_F(LAMMPS_commands, from_string) {
    std::string cmds("");

    for (unsigned int i=0; i < sizeof(demo_input)/sizeof(char *); ++i) {
        cmds += demo_input[i];
        cmds += "\n";
    }
    for (unsigned int i=0; i < sizeof(cont_input)/sizeof(char *); ++i) {
        cmds += cont_input[i];
        cmds += "\n";
    }
    EXPECT_EQ(lammps_get_natoms(lmp),0);
    lammps_commands_string(lmp,cmds.c_str());
    EXPECT_EQ(lammps_get_natoms(lmp),2);
};