text: /******************************************************************************
   * Copyright (C) 2014-2020 Zhifeng Gong <gozfree@163.com>
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   ******************************************************************************/
  #include "libconfig.h"
  #include <stdio.h>
  #include <stdlib.h>
  #include <stdarg.h>
  #include <string.h>
  #include <errno.h>
  
  
  extern struct config_ops ini_ops;
  extern struct config_ops json_ops;
  #ifdef ENABLE_LUA
  extern struct config_ops lua_ops;
  #endif
  
  struct config *g_config = NULL;
  
  struct config_ops_list {
      char suffix[32];
      struct config_ops *ops;
  };
  
  static struct config_ops_list conf_ops_list[] = {
  #ifdef ENABLE_LUA
      {"lua", &lua_ops},
  #endif
      {"json", &json_ops},
      {"ini", &ini_ops}
  };
  
  static char *get_file_suffix(const char *name)
  {
      int point = '.';
      char *tmp = strrchr((char *)name, point);
      if (tmp) {
          return tmp+1;
      }
      return NULL;
  }
  
  static struct config_ops *find_backend(const char *name)
  {
      int i = 0;
      int max_list;
      char *suffix;
      if (!name) {
          printf("config name can not be NULL\n");
          return NULL;
      }
      max_list = sizeof(conf_ops_list)/sizeof(conf_ops_list[0]);
      suffix = get_file_suffix(name);
      if (!suffix) {
          printf("there is no suffix in config name\n");
          return NULL;
      }
      for (i = 0; i < max_list; i++) {
          if (!strcasecmp(conf_ops_list[i].suffix, suffix)) {
              break;
          }
      }
      if (i == max_list) {
          printf("the %s file is not supported\n", suffix);
          return NULL;
      }
      return conf_ops_list[i].ops;
  }
  
  struct config *conf_load(const char *name)
  {
      struct config *c;
      struct config_ops *ops = find_backend(name);
      if (!ops) {
          printf("can not find valid config backend\n");
          return NULL;
      }
      c = (struct config *)calloc(1, sizeof(struct config));
      if (!c) {
          printf("malloc failed!\n");
          return NULL;
      }
      c->ops = ops;
      if (c->ops->load) {
          if (-1 == c->ops->load(c, name)) {
              free(c);
              return NULL;
          }
      }
      g_config = c;
      return c;
  }
  
  int conf_set(struct config *c, const char *key, const char *val)
  {
      if (!c || !c->ops->set_string)
          return -1;
      return c->ops->set_string(c, key, val, NULL);
  }
  
  void conf_del(struct config *c, const char *key)
  {
      if (!c || !c->ops->del)
          return;
      c->ops->del(c, key);
  }
  
  void conf_dump(struct config *c)
  {
      if (!c || !c->ops->dump)
          return;
      c->ops->dump(c, stderr);
  }
  
  int conf_save(struct config *c)
  {
      if (!c || !c->ops->save)
          return -1;
      return c->ops->save(c);
  }
  
  void conf_dump_to_file(FILE *f, struct config *c)
  {
      if (!c || !c->ops->dump)
          return;
      c->ops->dump(c, f);
  }
  
  void conf_unload(struct config *c)
  {
      if (c && c->ops->unload) {
          c->ops->unload(c);
      }
      free(c);
  }
  