/*
 *  rhnop
 *
 *  Copyright (C) 2011-2015 Christian Pointner <equinox@helsinki.at>
 *
 *  This file is part of rhnop.
 *
 *  rhnop is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  rhnop is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with rhnop. If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>

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

#include "l_pipe.h"
#include "config.h"

#define LUA_MAIN_LOOP_FUNC "main_loop"
#define QLISTENER DATAROOTDIR"/rhnop/qlistener.lua"
#define TCPSERVER DATAROOTDIR"/rhnop/tcpserver.lua"

#if LUA_VERSION_NUM > 501
static const luaL_Reg nopsyncd_lualibs[] = {
  {"_G", luaopen_base},
  {LUA_LOADLIBNAME, luaopen_package},
  {LUA_TABLIBNAME, luaopen_table},
  {LUA_STRLIBNAME, luaopen_string},
  {LUA_MATHLIBNAME, luaopen_math},
  {LUA_IOLIBNAME, luaopen_io},
  {LUA_OSLIBNAME, luaopen_os},
  {LUA_BITLIBNAME, luaopen_bit32},
  {LUA_PIPELIBNAME, luaopen_pipe},
  {NULL, NULL}
};
#else
static const luaL_Reg nopsyncd_lualibs[] = {
  {"", luaopen_base},
  {LUA_LOADLIBNAME, luaopen_package},
  {LUA_TABLIBNAME, luaopen_table},
  {LUA_STRLIBNAME, luaopen_string},
  {LUA_MATHLIBNAME, luaopen_math},
  {LUA_IOLIBNAME, luaopen_io},
  {LUA_OSLIBNAME, luaopen_os},
  {LUA_PIPELIBNAME, luaopen_pipe},
  {NULL, NULL}
};
#endif

int init_main_loop(lua_State *L, const char* filename)
{
  const luaL_Reg *lib = nopsyncd_lualibs;

#if LUA_VERSION_NUM > 501
  for (; lib->func; lib++) {
    luaL_requiref(L, lib->name, lib->func, 1);
    lua_pop(L, 1);
  }
#else
  for (; lib->func; lib++) {
    lua_pushcfunction(L, lib->func);
    lua_pushstring(L, lib->name);
    lua_call(L, 1, 0);
  }
#endif

  int ret = luaL_loadfile(L, filename);
  if(ret) {
    const char* err_str = luaL_checkstring(L, -1);
    switch(ret) {
    case LUA_ERRSYNTAX: fprintf(stderr, "luaL_loadfile() syntax error: %s\n", err_str); break;
    case LUA_ERRMEM: fprintf(stderr, "luaL_loadfile() malloc error: %s\n", err_str); break;
    case LUA_ERRFILE: fprintf(stderr, "lauL_loadfile() error: %s\n", err_str); break;
    default: fprintf(stderr, "luaL_loadfile() unknown error: %s\n", err_str); break;
    }
    return -1;
  }

  lua_pushstring(L, DATAROOTDIR);
  lua_setglobal(L, "rhnoplibdir");
  lua_pushstring(L, ETCDIR);
  lua_setglobal(L, "rhnopescdir");

  ret = lua_pcall(L, 0, 0, 0);
  if(ret) {
    const char* err_str = luaL_checkstring(L, -1);
    switch(ret) {
    case LUA_ERRRUN: fprintf(stderr, "lua_pcall() runtime error: %s\n", err_str); break;
    case LUA_ERRMEM: fprintf(stderr, "lua_pcall() malloc error: %s\n", err_str); break;
    case LUA_ERRERR: fprintf(stderr, "lua_pcall() error at error handler function: %s\n", err_str); break;
    }
    return -1;
  }

  return 0;
}

int call_main_loop(lua_State* L, const char* filename)
{
  lua_getglobal(L, LUA_MAIN_LOOP_FUNC);
  if(!lua_isfunction(L, -1)) {
    fprintf(stderr, "there is no function '%s' at file '%s'\n", LUA_MAIN_LOOP_FUNC, filename);
    return -1;
  };

  int ret = lua_pcall(L, 0, 1, 0);
  if(ret) {
    const char* err_str = luaL_checkstring(L, -1);
    switch(ret) {
    case LUA_ERRRUN: fprintf(stderr, "lua_pcall(%s:%s) runtime error: %s\n", filename, LUA_MAIN_LOOP_FUNC, err_str); break;
    case LUA_ERRMEM: fprintf(stderr, "lua_pcall(%s:%s) malloc error: %s\n", filename, LUA_MAIN_LOOP_FUNC, err_str); break;
    case LUA_ERRERR: fprintf(stderr, "lua_pcall(%s:%s) error at error handler function: %s\n", filename, LUA_MAIN_LOOP_FUNC, err_str); break;
    }
    return -1;
  }

  ret = lua_tointeger(L, 1);
  return ret;
}

void* main_loop(void* file)
{
  if(!file)
    pthread_exit(NULL);


  lua_State *L;
  L = luaL_newstate();
  if(!L) {
    fprintf(stderr, "error creating lua state\n");
    pthread_exit(NULL);
  }

  int ret = init_main_loop(L, (char*)file);
  if(!ret)
    ret = call_main_loop(L, (char*)file);

  printf("%s returned with %d\n", (char*)file, ret);

  lua_close(L);

  /* this should bring down the other thread as well
     at least this is true for the tcp-server thread */
  pipe_close();

  pthread_exit(NULL);
}

int main(int argc, char* argv[])
{
  printf("starting nopsyncd...\n");

  pthread_t qlistener, tcpserver;

  int ret = pipe_init();
  if(ret) {
    fprintf(stderr, "Error creating pipe: %s\n", strerror(errno));
    return 1;
  }

  ret = pthread_create(&qlistener, NULL, main_loop, QLISTENER);
  if(ret) {
    fprintf(stderr, "Error creating qlistener thread (code: %d)\n", ret);
    return 1;
  }
  pthread_detach(qlistener); /* can't kill this thread so don't join to it */

  ret = pthread_create(&tcpserver, NULL, main_loop, TCPSERVER);
  if(ret) {
    fprintf(stderr, "Error creating tcpserver thread (code: %d)\n", ret);
    return 1;
  }

/* this thread can't be cancelled so don't wait for it */
/*  pthread_join(qlistener, NULL); */
  pthread_join(tcpserver, NULL);

  printf("stopping nopsyncd.\n");
  return 0;
}