/* Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.

   This program 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; version 2 of the License.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#include <my_global.h>
#include "keys_container.h"

namespace keyring {

extern PSI_memory_key key_memory_KEYRING;

uchar *get_hash_key(const uchar *key, size_t *length,
                    my_bool not_used MY_ATTRIBUTE((unused)))
{
  std::string *key_signature= reinterpret_cast<const IKey *>(key)->get_key_signature();
  *length= key_signature->length();
  return reinterpret_cast<uchar *>(const_cast<char*>(key_signature->c_str()));
}


void free_hash_key(void* key)
{
  IKey *key_to_free= reinterpret_cast<IKey*>(key);
  delete key_to_free;
}

Keys_container::Keys_container(ILogger *logger)
 : keys_hash(new HASH)
 , logger(logger)
 , keyring_io(NULL)
{
  my_hash_clear(keys_hash);
}

Keys_container::~Keys_container()
{
  free_keys_hash();
  delete keys_hash;
  if (keyring_io != NULL)
    delete keyring_io;
}

my_bool Keys_container::init(IKeyring_io* keyring_io, std::string keyring_storage_url)
{
  this->keyring_io= keyring_io;
  this->keyring_storage_url= keyring_storage_url;
  if (my_hash_init(keys_hash, system_charset_info, 0x100, 0, 0,
                   (my_hash_get_key) get_hash_key, free_hash_key, HASH_UNIQUE,
                   key_memory_KEYRING) ||
      keyring_io->init(&this->keyring_storage_url) ||
      load_keys_from_keyring_storage())
  {
    free_keys_hash();
    return TRUE;
  }
  return FALSE;
}

std::string Keys_container::get_keyring_storage_url()
{
  return keyring_storage_url;
}

void Keys_container::store_keys_metadata(IKey *key)
{
  /* if key metadata not present store it */
  Key_metadata km(key->get_key_id(), key->get_user_id());
  keys_metadata.push_back(km);
}

my_bool Keys_container::store_key_in_hash(IKey *key)
{
  if (my_hash_insert(keys_hash, (uchar *) key))
    return TRUE;
  store_keys_metadata(key);
  return FALSE;
}

my_bool Keys_container::store_key(IKey* key)
{
  if (flush_to_backup() || store_key_in_hash(key))
    return TRUE;
  if (flush_to_storage(key, STORE_KEY))
  {
    remove_key_from_hash(key);
    return TRUE;
  }
  return FALSE;
}

IKey* Keys_container::get_key_from_hash(IKey *key)
{
  return reinterpret_cast<IKey*>(my_hash_search(keys_hash,
    reinterpret_cast<const uchar*>(key->get_key_signature()->c_str()),
    key->get_key_signature()->length()));
}

void Keys_container::allocate_and_set_data_for_key(IKey *key,
                                                   std::string *source_key_type,
                                                   uchar *source_key_data,
                                                   size_t source_key_data_size)
{
  key->set_key_type(source_key_type);
  uchar *key_data= keyring_malloc<uchar*>(source_key_data_size);
  memcpy(key_data, source_key_data, source_key_data_size);
  key->set_key_data(key_data, source_key_data_size);
}

IKey*Keys_container::fetch_key(IKey *key)
{
  DBUG_ASSERT(key->get_key_data() == NULL);
  DBUG_ASSERT(key->get_key_type()->empty());

  IKey *fetched_key= get_key_from_hash(key);

  if (fetched_key == NULL)
    return NULL;

  if (fetched_key->get_key_type()->empty())
    return NULL;

  allocate_and_set_data_for_key(key, fetched_key->get_key_type(),
                                fetched_key->get_key_data(),
                                fetched_key->get_key_data_size());
  return key;
}

bool Keys_container::remove_keys_metadata(IKey *key)
{
  Key_metadata src(key->get_key_id(), key->get_user_id());
  std::vector<Key_metadata>::iterator it= keys_metadata.begin();
  while(it != keys_metadata.end())
  {
    if (src.id == it->id && src.user == it->user)
    {
      keys_metadata.erase(it);
      return false;
    }
    ++it;
  }
  return true;
}

my_bool Keys_container::remove_key_from_hash(IKey *key)
{
  my_bool retVal= TRUE;
  keys_hash->free= NULL; //Prevent my_hash_delete from removing key from memory
  retVal= my_hash_delete(keys_hash, reinterpret_cast<uchar*>(key));
  keys_hash->free= free_hash_key;
  remove_keys_metadata(key);
  return retVal;
}

my_bool Keys_container::remove_key(IKey *key)
{
  IKey* fetched_key_to_delete= get_key_from_hash(key);
  if (fetched_key_to_delete == NULL || flush_to_backup() ||
      remove_key_from_hash(fetched_key_to_delete))
    return TRUE;
  if (flush_to_storage(fetched_key_to_delete, REMOVE_KEY))
  {
    //reinsert the key
    store_key_in_hash(fetched_key_to_delete);
    return TRUE;
  }
  //successfully removed the key from hash and flushed to disk, safely remove
  //the key
  delete fetched_key_to_delete;

  return FALSE;
}

void Keys_container::free_keys_hash()
{
  if (my_hash_inited(keys_hash))
    my_hash_free(keys_hash);
}

my_bool Keys_container::load_keys_from_keyring_storage()
{
  my_bool was_error= FALSE;
  ISerialized_object *serialized_keys= NULL;
  was_error= keyring_io->get_serialized_object(&serialized_keys);
  while(was_error == FALSE && serialized_keys != NULL)
  {
    IKey *key_loaded= NULL;
    while(serialized_keys->has_next_key())
    {
      if (serialized_keys->get_next_key(&key_loaded) || key_loaded == NULL ||
          key_loaded->is_key_valid() == FALSE || store_key_in_hash(key_loaded))
      {
        was_error=TRUE;
        delete key_loaded;
        break;
      }
      key_loaded=NULL;
    }
    delete serialized_keys;
    serialized_keys= NULL;
    if (was_error == FALSE && keyring_io->has_next_serialized_object())
      was_error= keyring_io->get_serialized_object(&serialized_keys);
  }
  if(was_error)
    logger->log(MY_ERROR_LEVEL, "Error while loading keyring content. "
                                "The keyring might be malformed");
  return was_error;
}

my_bool Keys_container::flush_to_storage(IKey *key, Key_operation operation)
{
  ISerialized_object *serialized_object=
    keyring_io->get_serializer()->serialize(keys_hash, key, operation);

  if (serialized_object == NULL || keyring_io->flush_to_storage(serialized_object))
  {
    logger->log(MY_ERROR_LEVEL, "Could not flush keys to keyring");
    delete serialized_object;
    return TRUE;
  }
  delete serialized_object;
  return FALSE;
}

my_bool Keys_container::flush_to_backup()
{
  ISerialized_object *serialized_object=
    keyring_io->get_serializer()->serialize(keys_hash, NULL, NONE);

  if (serialized_object == NULL || keyring_io->flush_to_backup(serialized_object))
  {
    logger->log(MY_ERROR_LEVEL, "Could not flush keys to keyring's backup");
    delete serialized_object;
    return TRUE;
  }
  delete serialized_object;
  return FALSE;
}

} //namespace keyring