#include "package.h"

#include "lauxlib.h"
#include "lualib.h"
#include "malloc.h"
#include "pow_lua.h"
#include "stdio.h"
#include "string.h"

int extract_package_info(lua_State *L, pow_package *pkg) {
  lua_getfield(L, -1, "name");

  if (!lua_isstring(L, -1)) {
    printf("invalid package, name is not string (or doesn't exist)\n");

    return 1;
  }

  pkg->name = strdup(lua_tostring(L, -1));

  if (!pkg->name) {
    printf("strdup failed trying to get package name\n");

    return 1;
  }

  lua_pop(L, 1);

  lua_getfield(L, -1, "version");

  if (!lua_isstring(L, -1)) {
    printf("invalid package, version is not string (or doesn't exist)\n");

    return 1;
  }

  pkg->version = strdup(lua_tostring(L, -1));

  lua_pop(L, 1);

  if (!pkg->version) {
    printf("strdup failed trying to get package name\n");

    return 1;
  }

  return 0;
}

int pow_package_open(pow_package *pkg, const char *path) {
  FILE *fp;
  int c;
  int err;

  fp = fopen(path, "r");

  if (!fp) {
    printf("error opening package definition, doesn't exist?\n");

    return 1;
  }

  char *package_buffer = malloc(4096);

  size_t total = 0;
  size_t capacity = 4096;

  while ((c = fgetc(fp)) != EOF) {
    if (total + 1 >= capacity) {
      capacity *= 2;

      char *tmp = realloc(package_buffer, capacity);

      if (!tmp) {
        fclose(fp);

        printf("failed to realloc package buffer\n");

        return 1;
      }

      printf("reallocated package buffer due to size constraints\n");

      package_buffer = tmp;
    }

    package_buffer[total++] = c;
  }

  package_buffer[total] = '\0';

  lua_State *L = luaL_newstate();

  pkg->L = L;

  luaL_openlibs(L);
  pow_lua_load(L);

  luaL_loadstring(L, package_buffer);

  err = lua_pcall(L, 0, 1, 0);

  free(package_buffer);

  if (err) {
    printf("%s\n", lua_tostring(L, -1));

    return 1;
  }

  if (!lua_istable(L, -1)) {
    printf("invalid package, scripts must return table\n");

    return 1;
  }

  extract_package_info(L, pkg);

  pkg->path = path;
  pkg->pkg_ref = luaL_ref(L, LUA_REGISTRYINDEX);

  return 0;
}

int pow_package_close(pow_package *pkg) {
  free(pkg->name);
  free(pkg->version);

  lua_close(pkg->L);

  return 0;
}