Binding LaunchDarkly C SDK to Lua

lua-launchdarkly.c

#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include <launchdarkly/api.h>

#include <openssl/sha.h>

#include <lua.h>
#include <lauxlib.h>

static struct LDClient *launchdarkly_client = NULL;

static inline void launchdarkly_init()
{
  const char *key = getenv("LAUNCHDARKLY_APIKEY");
  if (key == NULL) {
    return;
  }

  LDConfigureGlobalLogger(LD_LOG_ERROR, LDBasicLogger);
  LDGlobalInit();

  unsigned int maxwaitmilliseconds = 2000;
  struct LDConfig *config = LDConfigNew(key);
  launchdarkly_client = LDClientInit(config, maxwaitmilliseconds);
}

bool launchdarkly_enabled(const char* name, const char* key)
{
  unsigned char hash[SHA_DIGEST_LENGTH];
  SHA1(key, strlen(key), hash);

  struct LDUser *user = LDUserNew(hash);
  LDUserSetAnonymous(user, true);

  bool result = LDBoolVariation(launchdarkly_client, user, name, false, NULL);
  LDUserFree(user);
  return result;
}

int launchdarkly_is_enabled(lua_State *L)
{
  const char *name = luaL_checkstring(L, 1);
  const char *ip_address = luaL_checkstring(L, 2);
  bool result = launchdarkly_enabled(name, ip_address);
  lua_pushboolean(L, result);
  return 1;
}

int luaopen_launchdarkly(lua_State *L)
{
  launchdarkly_init();

  lua_newtable(L);
  lua_pushcfunction(L, launchdarkly_is_enabled);
  lua_setfield(L, -2, "isEnabled");
  return 1;
}