#include <lean/lean.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>


typedef struct mathVec {
    uint32_t length;
    float*   data;
} mathVec;

static lean_external_class* g_mathVec_external_class = NULL;

 lean_obj_res make_error(const char* err_msg) {
    return lean_mk_io_user_error(lean_mk_io_user_error(lean_mk_string(err_msg)));
}

void mathVec_finalizer(void* v_) {
    mathVec* v = (mathVec*) v_;
    if (v->data) {
        free(v->data);
    }
    free(v);
}

void noop_foreach(void* mod, b_lean_obj_arg fn) {}

lean_obj_res mathVec_initialize() {
    g_mathVec_external_class = lean_register_external_class(
        mathVec_finalizer,
        noop_foreach
    );
    return lean_io_result_mk_ok(lean_box(0));
}

mathVec* mathVec_alloc(uint32_t length){
    mathVec* out = (mathVec*) malloc(sizeof(mathVec));
    if (out == NULL) {
        printf("idk im just not gonna deal with this lol\n");
    }

    out->data = (float*)(malloc(sizeof(float)*length));
    if (out->data == NULL) {
        printf("meh\n");
    }

    out->length = length;
    return out;
}

lean_object* mathVec_boxer(mathVec* v) {
    return lean_alloc_external(g_mathVec_external_class, v);
}

mathVec* mathVec_unboxer(lean_object* o) {
    return (mathVec*) lean_get_external_data(o);
}

lean_obj_res mathVec_new(uint32_t length, float x) {
    if (length < 0) {
        return make_error("invalid length");
    }

    mathVec* v = mathVec_alloc(length);
    if (!v) {
        return make_error("ERROR_INSUF_MEM");
    }
    for (uint32_t i = 0; i < v->length; i++) {
        v->data[i] = x;
    }
    return lean_io_result_mk_ok(mathVec_boxer(v));
}

lean_obj_res mathVec_get_val(b_lean_obj_arg _v, uint32_t i) {
    mathVec* v = mathVec_unboxer(_v);
    if (i > v->length){
        return make_error("sad");
    }
    return lean_io_result_mk_ok(lean_box_float(v->data[i]));
}