#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <raylib.h>

#include <lua.h>

#include "types.h"

void lua_ontick(){

}

void lua_onframe(){

}

static int lua_add_machine(lua_State *L){

  return 0;
}

static int lua_mtprint(lua_State *L){
  printf("(lua) %s\n", lua_tostring(L, 0)); 

  return 0;
}

struct LuaFn {
  char *name;
  lua_CFunction fn;
};

struct LuaFn exported_funcs[] = {
  {"mtprint", lua_mtprint}
};

// Taken from the Lua manual
static void *l_alloc (void *ud, void *ptr, size_t osize,size_t nsize){
 (void)ud;  (void)osize;  /* not used */
 if (nsize == 0) {
     free(ptr);
     return NULL;
 }
 else
   return realloc(ptr, nsize);
}

struct load_dat {
  char *str;
  int pos;
  int len;
};

const char *file_reader(lua_State *L, void *data, size_t *size){
  (void)L;
  struct load_dat *dat = data;
  if(dat->pos >= dat->len){
    *size = 0;
    return NULL; 
  }
  else{
    *size = dat->len;
    dat->pos += *size;
    return dat->str;
  }
}

lua_State *gl_L;

void script_init(){
  gl_L = lua_newstate(l_alloc, NULL);

  for(int i = 0; i < sizeof(exported_funcs)/sizeof(*exported_funcs); i++)
      lua_register(gl_L, exported_funcs[i].name, exported_funcs[i].fn);

  struct load_dat dat = {"mtprint(\"hello\")", 0};
  dat.len = strlen(dat.str);
  lua_load(gl_L, file_reader, &dat, "test", "t");
  int results = 0;
  lua_resume(gl_L, NULL, 0, &results);
}

void script_clean(){
  lua_close(gl_L);
}