/*
 * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
 * Copyright (C) 1999-2001 Hiroyuki Yamamoto
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "defs.h"

#include <glib.h>

#include <time.h>

#include "intl.h"
#include "msgcache.h"
#include "utils.h"
#include "procmsg.h"

typedef enum
{
	DATA_READ,
	DATA_WRITE,
	DATA_APPEND
} DataOpenMode;

struct _MsgCache {
	GHashTable	*msgnum_table;
	GHashTable	*msgid_table;
	guint		 memusage;
	time_t		 last_access;
};

MsgCache *msgcache_new(void)
{
	MsgCache *cache;
	
	cache = g_new0(MsgCache, 1),
	cache->msgnum_table = g_hash_table_new(g_int_hash, g_int_equal);
	cache->msgid_table = g_hash_table_new(g_str_hash, g_str_equal);
	cache->last_access = time(NULL);

	return cache;
}

static gboolean msgcache_msginfo_free_func(gpointer num, gpointer msginfo, gpointer user_data)
{
	procmsg_msginfo_free((MsgInfo *)msginfo);
	return TRUE;
}											  

void msgcache_destroy(MsgCache *cache)
{
	g_return_if_fail(cache != NULL);

	g_hash_table_foreach_remove(cache->msgnum_table, msgcache_msginfo_free_func, NULL);
	g_hash_table_destroy(cache->msgid_table);
	g_hash_table_destroy(cache->msgnum_table);
	g_free(cache);
}

void msgcache_add_msg(MsgCache *cache, MsgInfo *msginfo) 
{
	MsgInfo *newmsginfo;

	g_return_if_fail(cache != NULL);
	g_return_if_fail(msginfo != NULL);

	newmsginfo = procmsg_msginfo_new_ref(msginfo);
	g_hash_table_insert(cache->msgnum_table, &newmsginfo->msgnum, newmsginfo);
	if(newmsginfo->msgid != NULL)
		g_hash_table_insert(cache->msgid_table, newmsginfo->msgid, newmsginfo);
	cache->memusage += procmsg_msginfo_memusage(msginfo);
	cache->last_access = time(NULL);

	debug_print("Cache size: %d messages, %d bytes\n", g_hash_table_size(cache->msgnum_table), cache->memusage);
}

void msgcache_remove_msg(MsgCache *cache, guint msgnum)
{
	MsgInfo *msginfo;

	g_return_if_fail(cache != NULL);
	g_return_if_fail(msgnum > 0);

	msginfo = (MsgInfo *) g_hash_table_lookup(cache->msgnum_table, &msgnum);
	if(!msginfo)
		return;

	cache->memusage -= procmsg_msginfo_memusage(msginfo);
	if(msginfo->msgid)
		g_hash_table_remove(cache->msgid_table, msginfo->msgid);
	g_hash_table_remove(cache->msgnum_table, &msginfo->msgnum);
	procmsg_msginfo_free(msginfo);
	cache->last_access = time(NULL);

	debug_print("Cache size: %d messages, %d byte\n", g_hash_table_size(cache->msgnum_table), cache->memusage);
}

void msgcache_update_msg(MsgCache *cache, MsgInfo *msginfo)
{
	MsgInfo *oldmsginfo, *newmsginfo;
	
	g_return_if_fail(cache != NULL);
	g_return_if_fail(msginfo != NULL);

	oldmsginfo = g_hash_table_lookup(cache->msgnum_table, &msginfo->msgnum);
	if(msginfo) {
		g_hash_table_remove(cache->msgid_table, oldmsginfo->msgid);
		g_hash_table_remove(cache->msgnum_table, &oldmsginfo->msgnum);
		procmsg_msginfo_free(oldmsginfo);
	}
	cache->memusage -= procmsg_msginfo_memusage(oldmsginfo);

	newmsginfo = procmsg_msginfo_new_ref(msginfo);
	g_hash_table_insert(cache->msgnum_table, &newmsginfo->msgnum, newmsginfo);
	if(newmsginfo->msgid)
		g_hash_table_insert(cache->msgid_table, newmsginfo->msgid, newmsginfo);
	cache->memusage += procmsg_msginfo_memusage(newmsginfo);
	cache->last_access = time(NULL);
	
	debug_print("Cache size: %d messages, %d byte\n", g_hash_table_size(cache->msgnum_table), cache->memusage);

	return;
}

MsgInfo *msgcache_get_msg(MsgCache *cache, guint num)
{
	MsgInfo *msginfo;

	g_return_val_if_fail(cache != NULL, NULL);

	msginfo = g_hash_table_lookup(cache->msgnum_table, &num);
	if(!msginfo)
		return NULL;
	cache->last_access = time(NULL);
	
	return procmsg_msginfo_new_ref(msginfo);
}

MsgInfo *msgcache_get_msg_by_id(MsgCache *cache, const gchar *msgid)
{
	MsgInfo *msginfo;
	
	g_return_val_if_fail(cache != NULL, NULL);
	g_return_val_if_fail(msgid != NULL, NULL);

	msginfo = g_hash_table_lookup(cache->msgid_table, msgid);
	if(!msginfo)
		return NULL;
	cache->last_access = time(NULL);
	
	return procmsg_msginfo_new_ref(msginfo);	
}

static void msgcache_get_msg_list_func(gpointer key, gpointer value, gpointer user_data)
{
	MsgInfoList **listptr = user_data;
	MsgInfo *msginfo = value;

	*listptr = g_slist_prepend(*listptr, procmsg_msginfo_new_ref(msginfo));
}

MsgInfoList *msgcache_get_msg_list(MsgCache *cache)
{
	MsgInfoList *msg_list = NULL;

	g_return_val_if_fail(cache != NULL, NULL);

	g_hash_table_foreach((GHashTable *)cache->msgnum_table, msgcache_get_msg_list_func, (gpointer)&msg_list);	
	cache->last_access = time(NULL);
	
	msg_list = g_slist_reverse(msg_list);

	return msg_list;
}

time_t msgcache_get_last_access_time(MsgCache *cache)
{
	g_return_val_if_fail(cache != NULL, 0);
	
	return cache->last_access;
}

gint msgcache_get_memory_usage(MsgCache *cache)
{
	g_return_val_if_fail(cache != NULL, 0);

	return cache->memusage;
}

/*
 *  Cache saving functions
 */

#define READ_CACHE_DATA(data, fp) \
{ \
	if (msgcache_read_cache_data_str(fp, &data) < 0) { \
		procmsg_msginfo_free(msginfo); \
		error = TRUE; \
		break; \
	} \
}

#define READ_CACHE_DATA_INT(n, fp) \
{ \
	guint32 idata; \
 \
	if (fread(&idata, sizeof(idata), 1, fp) != 1) { \
		g_warning("Cache data is corrupted\n"); \
		procmsg_msginfo_free(msginfo); \
		error = TRUE; \
		break; \
	} else \
		n = idata;\
}

#define WRITE_CACHE_DATA_INT(n, fp)		\
{						\
	guint32 idata;				\
						\
	idata = (guint32)n;			\
	fwrite(&idata, sizeof(idata), 1, fp);	\
}

#define WRITE_CACHE_DATA(data, fp) \
{ \
	size_t len; \
	if (data == NULL) \
		len = 0; \
	else \
		len = strlen(data); \
	WRITE_CACHE_DATA_INT(len, fp); \
	if (len > 0) { \
		fwrite(data, len, 1, fp); \
	} \
}

static FILE *msgcache_open_data_file(const gchar *file, gint version,
				     DataOpenMode mode,
				     gchar *buf, size_t buf_size)
{
	FILE *fp;
	gint data_ver;

	g_return_val_if_fail(file != NULL, NULL);

	if (mode == DATA_WRITE) {
		if ((fp = fopen(file, "wb")) == NULL) {
			FILE_OP_ERROR(file, "fopen");
			return NULL;
		}
		if (change_file_mode_rw(fp, file) < 0)
			FILE_OP_ERROR(file, "chmod");

		WRITE_CACHE_DATA_INT(version, fp);
		return fp;
	}

	/* check version */
	if ((fp = fopen(file, "rb")) == NULL)
		debug_print("Mark/Cache file not found\n");
	else {
		if (buf && buf_size > 0)
			setvbuf(fp, buf, _IOFBF, buf_size);
		if (fread(&data_ver, sizeof(data_ver), 1, fp) != 1 ||
			 version != data_ver) {
			debug_print("Mark/Cache version is different (%d != %d). "
				    "Discarding it.\n", data_ver, version);
			fclose(fp);
			fp = NULL;
		}
	}

	if (mode == DATA_READ)
		return fp;

	if (fp) {
		/* reopen with append mode */
		fclose(fp);
		if ((fp = fopen(file, "ab")) == NULL)
			FILE_OP_ERROR(file, "fopen");
	} else {
		/* open with overwrite mode if mark file doesn't exist or
		   version is different */
		fp = msgcache_open_data_file(file, version, DATA_WRITE, buf,
					    buf_size);
	}

	return fp;
}

static gint msgcache_read_cache_data_str(FILE *fp, gchar **str)
{
	gchar buf[BUFFSIZE];
	gint ret = 0;
	guint32 len;

	if (fread(&len, sizeof(len), 1, fp) == 1) {
		if (len > G_MAXINT)
			ret = -1;
		else {
			gchar *tmp = NULL;

			while (len > 0) {
				size_t size = MIN(len, BUFFSIZE - 1);

				if (fread(buf, size, 1, fp) != 1) {
					ret = -1;
					if (tmp) g_free(tmp);
					*str = NULL;
					break;
				}

				buf[size] = '\0';
				if (tmp) {
					*str = g_strconcat(tmp, buf, NULL);
					g_free(tmp);
					tmp = *str;
				} else
					tmp = *str = g_strdup(buf);

				len -= size;
			}
		}
	} else
		ret = -1;

	if (ret < 0)
		g_warning("Cache data is corrupted\n");

	return ret;
}

MsgCache *msgcache_read_cache(FolderItem *item, const gchar *cache_file)
{
	MsgCache *cache;
	FILE *fp;
	MsgInfo *msginfo;
	MsgTmpFlags tmp_flags = 0;
	gchar file_buf[BUFFSIZE];
	guint num;
	gboolean error = FALSE;

	g_return_val_if_fail(cache_file != NULL, NULL);
	g_return_val_if_fail(item != NULL, NULL);

	if ((fp = msgcache_open_data_file
		(cache_file, CACHE_VERSION, DATA_READ, file_buf, sizeof(file_buf))) == NULL)
		return NULL;

	debug_print("\tReading message cache from %s...\n", cache_file);

	if (item->stype == F_QUEUE) {
		tmp_flags |= MSG_QUEUED;
	} else if (item->stype == F_DRAFT) {
		tmp_flags |= MSG_DRAFT;
	}

	cache = msgcache_new();

	g_hash_table_freeze(cache->msgnum_table);

	while (fread(&num, sizeof(num), 1, fp) == 1) {
		msginfo = procmsg_msginfo_new();
		msginfo->msgnum = num;
		READ_CACHE_DATA_INT(msginfo->size, fp);
		READ_CACHE_DATA_INT(msginfo->mtime, fp);
		READ_CACHE_DATA_INT(msginfo->date_t, fp);
		READ_CACHE_DATA_INT(msginfo->flags.tmp_flags, fp);

		READ_CACHE_DATA(msginfo->fromname, fp);

		READ_CACHE_DATA(msginfo->date, fp);
		READ_CACHE_DATA(msginfo->from, fp);
		READ_CACHE_DATA(msginfo->to, fp);
		READ_CACHE_DATA(msginfo->cc, fp);
		READ_CACHE_DATA(msginfo->newsgroups, fp);
		READ_CACHE_DATA(msginfo->subject, fp);
		READ_CACHE_DATA(msginfo->msgid, fp);
		READ_CACHE_DATA(msginfo->inreplyto, fp);
		READ_CACHE_DATA(msginfo->references, fp);
		READ_CACHE_DATA(msginfo->xref, fp);

		msginfo->folder = item;
		msginfo->flags.tmp_flags |= tmp_flags;

		g_hash_table_insert(cache->msgnum_table, &msginfo->msgnum, msginfo);
		if(msginfo->msgid)
			g_hash_table_insert(cache->msgid_table, msginfo->msgid, msginfo);
		cache->memusage += procmsg_msginfo_memusage(msginfo);
	}
	fclose(fp);
	g_hash_table_thaw(cache->msgnum_table);

	if(error) {
		msgcache_destroy(cache);
		return NULL;
	}

	cache->last_access = time(NULL);

	debug_print("done. (%d items read)\n", g_hash_table_size(cache->msgnum_table));
	debug_print("Cache size: %d messages, %d byte\n", g_hash_table_size(cache->msgnum_table), cache->memusage);

	return cache;
}

void msgcache_read_mark(MsgCache *cache, const gchar *mark_file)
{
	FILE *fp;
	MsgInfo *msginfo;
	MsgPermFlags perm_flags;
	guint num;

	if ((fp = msgcache_open_data_file(mark_file, MARK_VERSION, DATA_READ, NULL, 0)) == NULL)
		return;

	debug_print("\tReading message marks from %s...\n", mark_file);

	while (fread(&num, sizeof(num), 1, fp) == 1) {
		if (fread(&perm_flags, sizeof(perm_flags), 1, fp) != 1) break;

		msginfo = g_hash_table_lookup(cache->msgnum_table, &num);
		if(msginfo) {
			msginfo->flags.perm_flags = perm_flags;
		}
	}
	fclose(fp);
}

void msgcache_write_cache(MsgInfo *msginfo, FILE *fp)
{
	MsgTmpFlags flags = msginfo->flags.tmp_flags & MSG_CACHED_FLAG_MASK;

	WRITE_CACHE_DATA_INT(msginfo->msgnum, fp);
	WRITE_CACHE_DATA_INT(msginfo->size, fp);
	WRITE_CACHE_DATA_INT(msginfo->mtime, fp);
	WRITE_CACHE_DATA_INT(msginfo->date_t, fp);
	WRITE_CACHE_DATA_INT(flags, fp);

	WRITE_CACHE_DATA(msginfo->fromname, fp);

	WRITE_CACHE_DATA(msginfo->date, fp);
	WRITE_CACHE_DATA(msginfo->from, fp);
	WRITE_CACHE_DATA(msginfo->to, fp);
	WRITE_CACHE_DATA(msginfo->cc, fp);
	WRITE_CACHE_DATA(msginfo->newsgroups, fp);
	WRITE_CACHE_DATA(msginfo->subject, fp);
	WRITE_CACHE_DATA(msginfo->msgid, fp);
	WRITE_CACHE_DATA(msginfo->inreplyto, fp);
	WRITE_CACHE_DATA(msginfo->references, fp);
	WRITE_CACHE_DATA(msginfo->xref, fp);
}

static void msgcache_write_flags(MsgInfo *msginfo, FILE *fp)
{
	MsgPermFlags flags = msginfo->flags.perm_flags;

	WRITE_CACHE_DATA_INT(msginfo->msgnum, fp);
	WRITE_CACHE_DATA_INT(flags, fp);
}

struct write_fps
{
	FILE *cache_fp;
	FILE *mark_fp;
};

static void msgcache_write_func(gpointer key, gpointer value, gpointer user_data)
{
	MsgInfo *msginfo;
	struct write_fps *write_fps;

	msginfo = (MsgInfo *)value;
	write_fps = user_data;

	msgcache_write_cache(msginfo, write_fps->cache_fp);
	msgcache_write_flags(msginfo, write_fps->mark_fp);
}

gint msgcache_write(const gchar *cache_file, const gchar *mark_file, MsgCache *cache)
{
	struct write_fps write_fps;

	g_return_val_if_fail(cache_file != NULL, -1);
	g_return_val_if_fail(mark_file != NULL, -1);
	g_return_val_if_fail(cache != NULL, -1);

	write_fps.cache_fp = msgcache_open_data_file(cache_file, CACHE_VERSION,
		DATA_WRITE, NULL, 0);
	if (write_fps.cache_fp == NULL)
		return -1;

	write_fps.mark_fp = msgcache_open_data_file(mark_file, MARK_VERSION,
		DATA_WRITE, NULL, 0);
	if (write_fps.mark_fp == NULL) {
		fclose(write_fps.cache_fp);
		return -1;
	}

	debug_print("\tWriting message cache to %s and %s...\n", cache_file, mark_file);

	if (change_file_mode_rw(write_fps.cache_fp, cache_file) < 0)
		FILE_OP_ERROR(cache_file, "chmod");

	g_hash_table_foreach(cache->msgnum_table, msgcache_write_func, (gpointer)&write_fps);

	fclose(write_fps.cache_fp);
	fclose(write_fps.mark_fp);

	cache->last_access = time(NULL);

	debug_print("done.\n");
	return 0;
}