/*
#!/usr/bin/env zsh

for i in $(ls *.c)
do
  basename=$(echo ${i}|awk -F '.' '{ print $1}')
  sudo -u haproxy cc -I/usr/include/ -I/usr/include/lua5.3/ -fPIC -shared -o ${basename}.so ${i} -lcurl -ljansson -lmaxminddb
done
*/

#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <string.h>
#include <lua5.3/lua.h>
#include <lua5.3/lauxlib.h>
#include <curl/curl.h>
#include <maxminddb.h>
#include <jansson.h>

static MMDB_s mmdb;

const int STR_MAX_LEN = 255;

static int load_geoip(lua_State *L) {
  const char *filename = luaL_checkstring(L, 1);
  int status = MMDB_open(filename, MMDB_MODE_MMAP, &mmdb);
  if (status != 0) {
    printf("Error loading geoip database\n");
    exit(1);
  } else {
    printf("Loaded geoip database at: %s\n", filename);
  }
  return 0;
}

int get_geoip_info(const char* ip_address, MMDB_lookup_result_s* result) {
  int gai_error, mmdb_error;
  (*result) = MMDB_lookup_string(&mmdb, ip_address, &gai_error, &mmdb_error);

  if (0 != gai_error) {
    fprintf(stderr, "\n  Error from getaddrinfo for %s - %s\n\n", ip_address, gai_strerror(gai_error));
    exit(2);
  }

  if (MMDB_SUCCESS != mmdb_error) {
    fprintf(stderr, "\n  Got an error from libmaxminddb: %s\n\n", MMDB_strerror(mmdb_error));
    exit(3);
  }
  return 0;
}

int filter_value(MMDB_lookup_result_s* result,
    MMDB_entry_data_list_s** entry_data_list,
    MMDB_entry_data_s* entry_data,
    const char* query) {
  int status = MMDB_get_entry_data_list(&result->entry, entry_data_list);

  if (result->found_entry) {
    if (strcmp(query, "country") == 0) {
      status = MMDB_get_value(&result->entry, entry_data,
          "country",
          "iso_code",
          NULL);
      return status;
    } else if (strcmp(query, "city") == 0){
      status = MMDB_get_value(&result->entry, entry_data,
          "city",
          "names",
          "en",
          NULL);
      return status;
    }
  }
  return 1;
}

static int get_country(lua_State *L) {
  const char *ip_address = luaL_checkstring(L, 1);
  char country[STR_MAX_LEN];

  MMDB_entry_data_list_s *entry_data_list = NULL;
  MMDB_entry_data_s entry_data;
  MMDB_lookup_result_s result;

  get_geoip_info(ip_address, &result);

  int status = filter_value(&result, &entry_data_list, &entry_data, "country");

  if (status == 0) {
    sprintf(country, "%.*s", entry_data.data_size,entry_data.utf8_string);
  } else {
    strcpy(country, "not found");
  }

  lua_pushstring(L, country);
  return 1;
}

static int get_city(lua_State *L) {
  const char *ip_address = luaL_checkstring(L, 1);
  char city[STR_MAX_LEN];

  MMDB_entry_data_list_s *entry_data_list = NULL;
  MMDB_entry_data_s entry_data;
  MMDB_lookup_result_s result;

  get_geoip_info(ip_address, &result);

  int status = filter_value(&result, &entry_data_list, &entry_data, "city");

  if (status == 0) {
    sprintf(city, "%.*s", entry_data.data_size, entry_data.utf8_string);
  } else {
    strcpy(city, "not found");
  }

  lua_pushstring(L, city);
  return 1;
}

static int download_file() {
  return 0;
}

static int request(lua_State *L) {
  const char *url = luaL_checkstring(L, 1);
  CURL *curl = curl_easy_init();
  if (curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, url);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
  return 0;
}

/*
static void stackDump(lua_State *L)
{
  int i;
  int top = lua_gettop(L);

  for(i = 1; i <= top; i++) {
    int t = lua_type(L, i);
    switch(t) {
      case LUA_TNIL:
        printf("nil");
        break;
      case LUA_TBOOLEAN:
        printf(lua_toboolean(L, i) ? "true" : "false");
        break;
      case LUA_TNUMBER:
        printf("%g", lua_tonumber(L, i));
        break;
      case LUA_TSTRING:
        printf("%s", lua_tostring(L, i));
        break;

      default:
        printf("%s", lua_typename(L, t));
    }
    printf(" ");
  }
  printf("\n\n");
}*/


int get_info(lua_State *L) {
  lua_getglobal(L, "core");
  lua_getfield(L, -1, "get_info");

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

  if (err == 0) {
    lua_getfield(L, -1, "Build info");
    const char *version = lua_tostring(L, -1);
    printf("HAProxy version: %s\n",version);
  } else {
    printf("%d %s\n", err, lua_tostring(L, -1));
  }
  return 0;
}

int luaopen_haproxy(lua_State *L) {
  printf("Loading C lua module\n");

  lua_pushcfunction(L, load_geoip);
  lua_setglobal(L, "load_geoip");

  lua_pushcfunction(L, get_country);
  lua_setglobal(L, "get_country");

  lua_pushcfunction(L, get_city);
  lua_setglobal(L, "get_city");

  lua_pushcfunction(L, request);
  lua_setglobal(L, "request");
  return 0;
}