/*
 * Test for ECC-604: GRIB decoding/encoding sequentially and parallel with POSIX threads
 */
#include <time.h>
#include <pthread.h>
#include <assert.h>
#include <unistd.h>

#include "grib_api.h"

/* These are passed in via argv */
static size_t NUM_THREADS         = 0;
static size_t FILES_PER_ITERATION = 0;
static char*  INPUT_FILE          = NULL;
int opt_dump  = 0; /* If 1 then dump handle to /dev/null */
int opt_clone = 0; /* If 1 then clone source handle */
int opt_write = 0; /* If 1 write handle to file */

static int encode_file(char *template_file, char *output_file)
{
    FILE *in, *out=NULL;
    grib_handle *source_handle = NULL;
    const void *buffer = NULL;
    size_t size = 0;
    int err = 0;
    double *values;

    in = fopen(template_file,"rb"); assert(in);
    if (opt_write && output_file) {
        out = fopen(output_file,"wb");  assert(out);
    }

    /* loop over the messages in the source GRIB and clone them */
    while ((source_handle = grib_handle_new_from_file(0, in, &err))!=NULL) {
        int i;
        size_t values_len = 0;
        size_t str_len = 20;
        grib_handle *h = source_handle;
        
        if (opt_clone) {
            h = grib_handle_clone(source_handle); assert(h);
        }

        GRIB_CHECK(grib_get_size(h, "values", &values_len),0);

        values = (double*)malloc(values_len*sizeof(double));
        GRIB_CHECK(grib_get_double_array(h, "values", values, &values_len),0);

        for (i=0;i<values_len;i++) {
            values[i] *= 0.9;
        }

        GRIB_CHECK(grib_set_string(h,"stepUnits", "s", &str_len),0);
        GRIB_CHECK(grib_set_long(h, "startStep", 43200), 0);
        GRIB_CHECK(grib_set_long(h, "endStep", 86400), 0);
        GRIB_CHECK(grib_set_long(h, "bitsPerValue", 16),0);

        /* set data values */
        GRIB_CHECK(grib_set_double_array(h,"values",values,values_len),0);

        GRIB_CHECK(grib_get_message(h,&buffer,&size),0);
        if (opt_write) {
            if(fwrite(buffer,1,size,out) != size) {
                perror(output_file);
                return 1;
            }
        }
        if (opt_dump) {
            FILE *devnull = fopen("/dev/null", "w");
            grib_dump_content(source_handle,devnull, "debug", 0, NULL);
        }

        grib_handle_delete(source_handle);
        if(opt_clone) grib_handle_delete(h);
        free(values);
    }

    if (opt_write) fclose(out);
    fclose(in);

    return 0;
}

void do_stuff(void *data);

/* Structure for passing data to threads */
struct v {
    size_t number;
    char *data;
};

void *runner(void *ptr); /* the thread */

int main(int argc, char **argv)
{
    size_t i;
    int thread_counter = 0;
    int parallel=1, index=0, c=0;
    const char* prog = argv[0];
    char* mode;
    if (argc<5 || argc>8) {
        fprintf(stderr, "Usage:\n\t%s [options] seq file numRuns numIter\nOr\n\t%s [options] par file numThreads numIter\n", prog, prog);
        return 1;
    }
    
    while ((c = getopt (argc, argv, "dcw")) != -1) {
        switch (c) {
            case 'd': opt_dump=1; break;
            case 'c': opt_clone=1; break;
            case 'w': opt_write=1; break;
        }
    }
    index = optind;
    mode = argv[index];
    INPUT_FILE = argv[index+1];
    NUM_THREADS = atol(argv[index+2]);
    FILES_PER_ITERATION = atol(argv[index+3]);

    if (strcmp(mode,"seq")==0) {
        parallel = 0;
    }
    if (parallel) {
        printf("Running parallel in %ld threads. %ld iterations (prod=%ld)\n", NUM_THREADS, FILES_PER_ITERATION, NUM_THREADS*FILES_PER_ITERATION);
        printf("Options: dump=%d, clone=%d, write=%d\n", opt_dump, opt_clone, opt_write);
    } else {
        printf("Running sequentially in %ld runs. %ld iterations\n", NUM_THREADS, FILES_PER_ITERATION);
    }

    {
        pthread_t* workers = malloc(NUM_THREADS * sizeof(pthread_t));
        for (i = 0; i < NUM_THREADS; i++) {
            struct v *data = (struct v *) malloc(sizeof(struct v));
            data->number = i;
            data->data = NULL;

            if (parallel) {
                /* Now we will create the thread passing it data as an argument */
                pthread_create(&workers[thread_counter], NULL, runner, data);
                /*pthread_join(workers[thread_counter], NULL);*/
                thread_counter++;
            } else {
                do_stuff(data);
            }
        }

        if (parallel) {
            for (i = 0; i < NUM_THREADS; i++)  {
                pthread_join(workers[i], NULL);
            }
        }
        free (workers);
    }

    return 0;
}

void *runner(void *ptr)
{
    do_stuff(ptr);
    pthread_exit(0);
}

void do_stuff(void *ptr)
{
    /* Cast argument to struct v pointer */
    struct v *data = ptr;
    size_t i;
    char output_file[50];
    time_t ltime;
    struct tm result;
    char stime[32];

    for (i=0; i<FILES_PER_ITERATION;i++) {
        if (opt_write) {
            sprintf(output_file,"output/output_file_%ld-%ld.grib", data->number, i);
            encode_file(INPUT_FILE,output_file);
        } else {
            encode_file(INPUT_FILE,NULL);
        }
    }

    ltime = time(NULL);
    localtime_r(&ltime, &result);
    strftime(stime, 32, "%H:%M:%S", &result); /* Try to get milliseconds here too*/
    /* asctime_r(&result, stime); */

    printf("%s: Worker %ld finished.\n", stime, data->number);
}