#include <stdint.h>
#include "erl_nif.h"

#ifdef _WIN32
#define INLINE __inline
#else
#define INLINE inline
#endif

static ErlNifResourceType* ResType = NULL;
ERL_NIF_TERM null;
ERL_NIF_TERM ok;


static int load(ErlNifEnv* env, void** priv, ERL_NIF_TERM load_info)
{
    ErlNifResourceFlags flags = ERL_NIF_RT_CREATE | ERL_NIF_RT_TAKEOVER;
    ResType = enif_open_resource_type(env, NULL, "_nifArray_", NULL, flags, NULL);
    if(NULL == ResType)
        return -1;
    null = enif_make_atom(env, "null");
    ok = enif_make_atom(env, "ok");
    return 0;
}

static ERL_NIF_TERM new(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{
    uint32_t Size;
    if(!enif_get_uint(env, argv[0], &Size)) {
        return enif_make_badarg(env);
    }

    ErlNifBinary **ArrayPtr = (ErlNifBinary **) enif_alloc_resource(ResType, sizeof(ErlNifBinary*)*Size);
    int i;
    for(i = 0; i < Size; i++){
        ArrayPtr[i] = NULL;
    }
    ERL_NIF_TERM Res = enif_make_resource(env, ArrayPtr);
    enif_release_resource(ArrayPtr);
    return Res;
}

static ERL_NIF_TERM get(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{
    uint32_t Index;
    if(!enif_get_uint(env, argv[1], &Index)) {
        return enif_make_badarg(env);
    }

    ErlNifBinary **ArrayPtr;

    if (!enif_get_resource(env, argv[0], ResType, (void**)&ArrayPtr)){
        return enif_make_badarg(env);
    }
    if(NULL != ArrayPtr[Index]){
        ERL_NIF_TERM Ret;
        enif_binary_to_term(env, ArrayPtr[Index]->data, ArrayPtr[Index]->size, &Ret, 0);
        return Ret;
    } else{
        return null;
    }
}

static ERL_NIF_TERM put(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{
    uint32_t Index;
    if(!enif_get_uint(env, argv[1], &Index)) {
        return enif_make_badarg(env);
    }

    ErlNifBinary *Value = (ErlNifBinary *)malloc(sizeof(ErlNifBinary));
    if(!enif_term_to_binary(env, argv[2], Value))
        return enif_make_badarg(env);

    ErlNifBinary **ArrayPtr;

    if (!enif_get_resource(env, argv[0], ResType, (void**)&ArrayPtr)){
        return enif_make_badarg(env);
    }
    if(NULL == ArrayPtr[Index]){
         ArrayPtr[Index] = Value;
        return ok;
    } else{
        enif_release_binary(ArrayPtr[Index]),
        free(ArrayPtr[Index]);
        ArrayPtr[Index] = Value;
        return ok;
    }
}

static ERL_NIF_TERM test(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{
    ErlNifBinary Value;
    if(!enif_term_to_binary(env, argv[0], &Value))
        return enif_make_badarg(env);
    // enif_fprintf(stdout, "IMY************  %T", argv[0]);
    ERL_NIF_TERM Ret;
    enif_binary_to_term(env, Value.data, Value.size, &Ret, 0);
    enif_release_binary(&Value);
    return Ret;
}

static ErlNifFunc nifFuns[] = {
        {"new", 1, new},
        {"get", 2, get},
        {"put", 3, put},
        {"test", 1, test},
};

ERL_NIF_INIT(nifArray, nifFuns, &load, NULL, NULL, NULL)