/*
 * libEtPan! -- a mail stuff library
 *
 * Copyright (C) 2001, 2002 - DINH Viet Hoa
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the libEtPan! project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * $Id$
 */

#include "mboxdriver_cached_message.h"

#include "mailmessage_tools.h"
#include "mboxdriver_tools.h"
#include "mboxdriver_cached.h"
#include "mboxdriver.h"
#include "mailmbox.h"
#include "mail_cache_db.h"
#include "generic_cache.h"

#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>

static int mbox_prefetch(mailmessage * msg_info);

static void mbox_prefetch_free(struct generic_message_t * msg);

static int mbox_initialize(mailmessage * msg_info);

static void mbox_uninitialize(mailmessage * msg_info);

static void mbox_flush(mailmessage * msg_info);

static void mbox_check(mailmessage * msg_info);

static int mbox_fetch_size(mailmessage * msg_info,
			   size_t * result);

static int mbox_get_flags(mailmessage * msg_info,
			  struct mail_flags ** result);

static int mbox_fetch_header(mailmessage * msg_info,
			   char ** result,
			     size_t * result_len);

static mailmessage_driver local_mbox_cached_message_driver = {
  .msg_name = "mbox-cached",

  .msg_initialize = mbox_initialize,
  .msg_uninitialize = mbox_uninitialize,

  .msg_flush = mbox_flush,
  .msg_check = mbox_check,

  .msg_fetch_result_free = mailmessage_generic_fetch_result_free,

  .msg_fetch = mailmessage_generic_fetch,
  .msg_fetch_header = mbox_fetch_header,
  .msg_fetch_body = mailmessage_generic_fetch_body,
  .msg_fetch_size = mbox_fetch_size,
  .msg_get_bodystructure = mailmessage_generic_get_bodystructure,
  .msg_fetch_section = mailmessage_generic_fetch_section,
  .msg_fetch_section_header = mailmessage_generic_fetch_section_header,
  .msg_fetch_section_mime = mailmessage_generic_fetch_section_mime,
  .msg_fetch_section_body = mailmessage_generic_fetch_section_body,
  .msg_fetch_envelope = mailmessage_generic_fetch_envelope,

  .msg_get_flags = mbox_get_flags,
};

mailmessage_driver * mbox_cached_message_driver =
&local_mbox_cached_message_driver;

static inline struct mbox_cached_session_state_data *
get_cached_session_data(mailmessage * msg)
{
  return msg->msg_session->sess_data;
}

static inline mailsession * get_ancestor_session(mailmessage * msg)
{
  return get_cached_session_data(msg)->mbox_ancestor;
}

static inline struct mbox_session_state_data *
get_ancestor_session_data(mailmessage * msg)
{
  return get_ancestor_session(msg)->sess_data;
}

static inline struct mailmbox_folder *
get_mbox_session(mailmessage * msg)
{
  return get_ancestor_session_data(msg)->mbox_folder;
}

static int mbox_prefetch(mailmessage * msg_info)
{
  struct generic_message_t * msg;
  int r;
  char * msg_content;
  size_t msg_length;

  r = mboxdriver_fetch_msg(get_ancestor_session(msg_info),
      msg_info->msg_index,
      &msg_content, &msg_length);
  if (r != MAIL_NO_ERROR)
    return r;

  msg = msg_info->msg_data;

  msg->msg_message = msg_content;
  msg->msg_length = msg_length;

  return MAIL_NO_ERROR;
}

static void mbox_prefetch_free(struct generic_message_t * msg)
{
  if (msg->msg_message != NULL) {
    mmap_string_unref(msg->msg_message);
    msg->msg_message = NULL;
  }
}

static int mbox_initialize(mailmessage * msg_info)
{
  struct generic_message_t * msg;
  int r;
  char * uid;
  char static_uid[PATH_MAX];
  struct mailmbox_msg_info * info;
  struct mailmbox_folder * folder;
  int res;
  chashdatum key;
  chashdatum data;

  folder = get_mbox_session(msg_info);
  if (folder == NULL) {
    res = MAIL_ERROR_BAD_STATE;
    goto err;
  }
    
  key.data = (char *) &msg_info->msg_index;
  key.len = sizeof(msg_info->msg_index);
  
  r = chash_get(folder->mb_hash, &key, &data);
  if (r < 0) {
    res = MAIL_ERROR_MSG_NOT_FOUND;
    goto err;
  }
  
  info = (struct mailmbox_msg_info *) data.data;
  
  snprintf(static_uid, PATH_MAX, "%u-%lu",
      msg_info->msg_index, (unsigned long) info->msg_body_len);
  uid = strdup(static_uid);
  if (uid == NULL) {
    res = MAIL_ERROR_MEMORY;
    goto err;
  }
  
  r = mailmessage_generic_initialize(msg_info);
  if (r != MAIL_NO_ERROR) {
    free(uid);
    res = r;
    goto err;
  }

  msg = msg_info->msg_data;

  msg->msg_prefetch = mbox_prefetch;
  msg->msg_prefetch_free = mbox_prefetch_free;
  msg_info->msg_uid = uid;

  return MAIL_NO_ERROR;

 err:
  return res;
}

static void mbox_uninitialize(mailmessage * msg_info)
{
  mailmessage_generic_uninitialize(msg_info);
}

#define FLAGS_NAME "flags.db"

static void mbox_flush(mailmessage * msg_info)
{
  mailmessage_generic_flush(msg_info);
}

static void mbox_check(mailmessage * msg_info)
{
  int r;

  if (msg_info->msg_flags != NULL) {
    r = mail_flags_store_set(get_cached_session_data(msg_info)->mbox_flags_store,
        msg_info);
    /* ignore errors */
  }
}

     
static int mbox_fetch_size(mailmessage * msg_info,
			   size_t * result)
{
  int r;
  size_t size;

  r = mboxdriver_fetch_size(get_ancestor_session(msg_info),
			    msg_info->msg_index, &size);
  if (r != MAIL_NO_ERROR)
    return r;
  
  * result = size;

  return MAIL_NO_ERROR;
}

static int mbox_get_flags(mailmessage * msg_info,
			  struct mail_flags ** result)
{
  int r;
  struct mail_flags * flags;
  struct mail_cache_db * cache_db_flags;
  char filename_flags[PATH_MAX];
  int res;
  struct mbox_cached_session_state_data * cached_data;
  MMAPString * mmapstr;
  struct mailmbox_folder * folder;

  if (msg_info->msg_flags != NULL) {
    * result = msg_info->msg_flags;
    
    return MAIL_NO_ERROR;
  }

  flags = mail_flags_store_get(get_cached_session_data(msg_info)->mbox_flags_store,
      msg_info->msg_index);

  if (flags == NULL) {
    folder = get_mbox_session(msg_info);
    if (folder == NULL) {
      res = MAIL_ERROR_BAD_STATE;
      goto err;
    }
    
    cached_data = get_cached_session_data(msg_info);
    if (cached_data->mbox_quoted_mb == NULL) {
      res = MAIL_ERROR_BAD_STATE;
      goto err;
    }
    
    snprintf(filename_flags, PATH_MAX, "%s/%s/%s",
        cached_data->mbox_flags_directory,
        cached_data->mbox_quoted_mb, FLAGS_NAME);
    
    r = mail_cache_db_open_lock(filename_flags, &cache_db_flags);
    if (r < 0) {
      res = MAIL_ERROR_MEMORY;
      goto err;
    }
    
    mmapstr = mmap_string_new("");
    if (mmapstr == NULL) {
      res = MAIL_ERROR_MEMORY;
      goto close_db_flags;
    }
    
    if (msg_info->msg_index > folder->mb_written_uid) {
      flags = mail_flags_new_empty();
    }
    else {
      r = mboxdriver_get_cached_flags(cache_db_flags, mmapstr,
          msg_info->msg_session,
          msg_info->msg_index, &flags);
      if (r != MAIL_NO_ERROR) {
	flags = mail_flags_new_empty();
	if (flags == NULL) {
	  res = MAIL_ERROR_MEMORY;
	  goto free_mmapstr;
	}
      }
    }

    mmap_string_free(mmapstr);
    mail_cache_db_close_unlock(filename_flags, cache_db_flags);
  }
  
  msg_info->msg_flags = flags;

  * result = flags;

  return MAIL_NO_ERROR;

 free_mmapstr:
  mmap_string_free(mmapstr);
 close_db_flags:
  mail_cache_db_close_unlock(filename_flags, cache_db_flags);
 err:
  return res;
}

static int mbox_fetch_header(mailmessage * msg_info,
			   char ** result,
			   size_t * result_len)
{
  struct generic_message_t * msg;
  int r;
  char * msg_content;
  size_t msg_length;

  msg = msg_info->msg_data;
  if (msg->msg_message != NULL) {
    return mailmessage_generic_fetch_header(msg_info, result, result_len);
  }
  else {
    r = mboxdriver_fetch_header(get_ancestor_session(msg_info),
				msg_info->msg_index,
				&msg_content, &msg_length);
    if (r != MAIL_NO_ERROR)
      return r;
    
    * result = msg_content;
    * result_len = msg_length;
    
    return MAIL_NO_ERROR;
  }
}