#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if USE_MPI
#    include <mpi.h>
#endif
#include "lulesh.h"

/* Helper function for converting strings to ints, with error checking */
int
StrToInt(const char* token, int* retVal)
{
    const char* c;
    char*       endptr;
    const int   decimal_base = 10;

    if(token == NULL) return 0;

    c       = token;
    *retVal = (int) strtol(c, &endptr, decimal_base);
    if((endptr != c) && ((*endptr == ' ') || (*endptr == '\0')))
        return 1;
    else
        return 0;
}

static void
PrintCommandLineOptions(char* execname, int myRank)
{
    if(myRank == 0)
    {
        printf("Usage: %s [opts]\n", execname);
        printf(" where [opts] is one or more of:\n");
        printf(" -q              : quiet mode - suppress all stdout\n");
        printf(" -i <iterations> : number of cycles to run\n");
        printf(" -s <size>       : length of cube mesh along side\n");
        printf(" -r <numregions> : Number of distinct regions (def: 11)\n");
        printf(" -b <balance>    : Load balance between regions of a domain (def: 1)\n");
        printf(" -c <cost>       : Extra cost of more expensive regions (def: 1)\n");
        printf(" -f <numfiles>   : Number of files to split viz dump into (def: "
               "(np+10)/9)\n");
        printf(" -p              : Print out progress\n");
        printf(
            " -v              : Output viz file (requires compiling with -DVIZ_MESH\n");
        printf(" -h              : This message\n");
        printf("\n\n");
    }
}

static void
ParseError(const char* message, int myRank)
{
    if(myRank == 0)
    {
        printf("%s\n", message);
#if USE_MPI
        MPI_Abort(MPI_COMM_WORLD, -1);
#else
        exit(-1);
#endif
    }
}

void
ParseCommandLineOptions(int argc, char* argv[], int myRank, struct cmdLineOpts* opts)
{
    if(argc > 1)
    {
        int i = 1;

        while(i < argc)
        {
            int ok;
            /* -i <iterations> */
            if(strcmp(argv[i], "-i") == 0)
            {
                if(i + 1 >= argc)
                {
                    ParseError("Missing integer argument to -i", myRank);
                }
                ok = StrToInt(argv[i + 1], &(opts->its));
                if(!ok)
                {
                    ParseError("Parse Error on option -i integer value required after "
                               "argument\n",
                               myRank);
                }
                i += 2;
            }
            /* -s <size, sidelength> */
            else if(strcmp(argv[i], "-s") == 0)
            {
                if(i + 1 >= argc)
                {
                    ParseError("Missing integer argument to -s\n", myRank);
                }
                ok = StrToInt(argv[i + 1], &(opts->nx));
                if(!ok)
                {
                    ParseError("Parse Error on option -s integer value required after "
                               "argument\n",
                               myRank);
                }
                i += 2;
            }
            /* -r <numregions> */
            else if(strcmp(argv[i], "-r") == 0)
            {
                if(i + 1 >= argc)
                {
                    ParseError("Missing integer argument to -r\n", myRank);
                }
                ok = StrToInt(argv[i + 1], &(opts->numReg));
                if(!ok)
                {
                    ParseError("Parse Error on option -r integer value required after "
                               "argument\n",
                               myRank);
                }
                i += 2;
            }
            /* -f <numfilepieces> */
            else if(strcmp(argv[i], "-f") == 0)
            {
                if(i + 1 >= argc)
                {
                    ParseError("Missing integer argument to -f\n", myRank);
                }
                ok = StrToInt(argv[i + 1], &(opts->numFiles));
                if(!ok)
                {
                    ParseError("Parse Error on option -f integer value required after "
                               "argument\n",
                               myRank);
                }
                i += 2;
            }
            /* -p */
            else if(strcmp(argv[i], "-p") == 0)
            {
                opts->showProg = 1;
                i++;
            }
            /* -q */
            else if(strcmp(argv[i], "-q") == 0)
            {
                opts->quiet = 1;
                i++;
            }
            /* -q */
            else if(strcmp(argv[i], "-a") == 0)
            {
                opts->do_atomic = 1;
                i++;
            }
            else if(strcmp(argv[i], "-b") == 0)
            {
                if(i + 1 >= argc)
                {
                    ParseError("Missing integer argument to -b\n", myRank);
                }
                ok = StrToInt(argv[i + 1], &(opts->balance));
                if(!ok)
                {
                    ParseError("Parse Error on option -b integer value required after "
                               "argument\n",
                               myRank);
                }
                i += 2;
            }
            else if(strcmp(argv[i], "-c") == 0)
            {
                if(i + 1 >= argc)
                {
                    ParseError("Missing integer argument to -c\n", myRank);
                }
                ok = StrToInt(argv[i + 1], &(opts->cost));
                if(!ok)
                {
                    ParseError("Parse Error on option -c integer value required after "
                               "argument\n",
                               myRank);
                }
                i += 2;
            }
            /* -v */
            else if(strcmp(argv[i], "-v") == 0)
            {
#if VIZ_MESH
                opts->viz = 1;
#else
                ParseError("Use of -v requires compiling with -DVIZ_MESH\n", myRank);
#endif
                i++;
            }
            /* -h */
            else if(strcmp(argv[i], "-h") == 0)
            {
                PrintCommandLineOptions(argv[0], myRank);
#if USE_MPI
                MPI_Abort(MPI_COMM_WORLD, 0);
#else
                exit(0);
#endif
            }
            else
            {
                char msg[80];
                PrintCommandLineOptions(argv[0], myRank);
                sprintf(msg, "ERROR: Unknown command line argument: %s\n", argv[i]);
                ParseError(msg, myRank);
            }
        }
    }
}

/////////////////////////////////////////////////////////////////////

void
VerifyAndWriteFinalOutput(Real_t elapsed_time, Domain& locDom, Int_t nx, Int_t numRanks)
{
    // GrindTime1 only takes a single domain into account, and is thus a good way to
    // measure processor speed indepdendent of MPI parallelism. GrindTime2 takes into
    // account speedups from MPI parallelism
    Real_t grindTime1 = ((elapsed_time * 1e6) / locDom.cycle()) / (nx * nx * nx);
    Real_t grindTime2 =
        ((elapsed_time * 1e6) / locDom.cycle()) / (nx * nx * nx * numRanks);

    Index_t ElemId = 0;
    auto    h_e    = Kokkos::create_mirror_view(locDom.e_view());
    Kokkos::deep_copy(h_e, locDom.e_view());
    printf("Run completed:  \n");
    printf("   Problem size        =  %i \n", nx);
    printf("   MPI tasks           =  %i \n", numRanks);
    printf("   Iteration count     =  %i \n", locDom.cycle());
    printf("   Final Origin Energy = %12.6e \n", h_e(ElemId));

    Real_t MaxAbsDiff   = Real_t(0.0);
    Real_t TotalAbsDiff = Real_t(0.0);
    Real_t MaxRelDiff   = Real_t(0.0);

    for(Index_t j = 0; j < nx; ++j)
    {
        for(Index_t k = j + 1; k < nx; ++k)
        {
            Real_t AbsDiff = FABS(h_e(j * nx + k) - h_e(k * nx + j));
            TotalAbsDiff += AbsDiff;

            if(MaxAbsDiff < AbsDiff) MaxAbsDiff = AbsDiff;

            Real_t RelDiff = AbsDiff / h_e(k * nx + j);

            if(MaxRelDiff < RelDiff) MaxRelDiff = RelDiff;
        }
    }

    // Quick symmetry check
    printf("   Testing Plane 0 of Energy Array on rank 0:\n");
    printf("        MaxAbsDiff   = %12.6e\n", MaxAbsDiff);
    printf("        TotalAbsDiff = %12.6e\n", TotalAbsDiff);
    printf("        MaxRelDiff   = %12.6e\n\n", MaxRelDiff);

    // Timing information
    printf("\nElapsed time         = %10.2f (s)\n", elapsed_time);
    printf("Grind time (us/z/c)  = %10.8g (per dom)  (%10.8g overall)\n", grindTime1,
           grindTime2);
    printf("FOM                  = %10.8g (z/s)\n\n",
           1000.0 / grindTime2);  // zones per second

    return;
}