/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-pop3-folder.c : class for a pop3 folder */

/* 
 * Authors:
 *   Dan Winship <danw@ximian.com>
 *   Michael Zucchi <notzed@ximian.com>
 *
 * Copyright (C) 2002 Ximian, Inc. (www.ximian.com)
 *
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of version 2 of the GNU General Public 
 * License as published by the Free Software Foundation.
 *
 * 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
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>

#include "camel-pop3-folder.h"
#include "camel-pop3-store.h"
#include "camel-exception.h"
#include "camel-stream-mem.h"
#include "camel-stream-filter.h"
#include "camel-mime-message.h"
#include "camel-operation.h"
#include "camel-data-cache.h"

#include <e-util/md5-utils.h>

#include <stdlib.h>
#include <string.h>

#define d(x)

#define CF_CLASS(o) (CAMEL_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(o)))
static CamelFolderClass *parent_class;

static void pop3_finalize (CamelObject *object);
static void pop3_refresh_info (CamelFolder *folder, CamelException *ex);
static void pop3_sync (CamelFolder *folder, gboolean expunge, CamelException *ex);
static gint pop3_get_message_count (CamelFolder *folder);
static GPtrArray *pop3_get_uids (CamelFolder *folder);
static CamelMimeMessage *pop3_get_message (CamelFolder *folder, const char *uid, CamelException *ex);
static void pop3_set_message_flags (CamelFolder *folder, const char *uid, guint32 flags, guint32 set);

static void
camel_pop3_folder_class_init (CamelPOP3FolderClass *camel_pop3_folder_class)
{
	CamelFolderClass *camel_folder_class =
		CAMEL_FOLDER_CLASS (camel_pop3_folder_class);
	
	parent_class = CAMEL_FOLDER_CLASS(camel_type_get_global_classfuncs (camel_folder_get_type ()));
	
	/* virtual method overload */
	camel_folder_class->refresh_info = pop3_refresh_info;
	camel_folder_class->sync = pop3_sync;
	
	camel_folder_class->get_message_count = pop3_get_message_count;
	camel_folder_class->get_uids = pop3_get_uids;
	camel_folder_class->free_uids = camel_folder_free_shallow;
	
	camel_folder_class->get_message = pop3_get_message;
	camel_folder_class->set_message_flags = pop3_set_message_flags;
}

CamelType
camel_pop3_folder_get_type (void)
{
	static CamelType camel_pop3_folder_type = CAMEL_INVALID_TYPE;
	
	if (!camel_pop3_folder_type) {
		camel_pop3_folder_type = camel_type_register (CAMEL_FOLDER_TYPE, "CamelPOP3Folder",
							      sizeof (CamelPOP3Folder),
							      sizeof (CamelPOP3FolderClass),
							      (CamelObjectClassInitFunc) camel_pop3_folder_class_init,
							      NULL,
							      NULL,
							      (CamelObjectFinalizeFunc) pop3_finalize);
	}
	
	return camel_pop3_folder_type;
}

void
pop3_finalize (CamelObject *object)
{
	CamelPOP3Folder *pop3_folder = CAMEL_POP3_FOLDER (object);
	CamelPOP3FolderInfo **fi = (CamelPOP3FolderInfo **)pop3_folder->uids->pdata;
	CamelPOP3Store *pop3_store = (CamelPOP3Store *)((CamelFolder *)pop3_folder)->parent_store;
	int i;

	for (i=0;i<pop3_folder->uids->len;i++,fi++) {
		if (fi[0]->cmd) {
			while (camel_pop3_engine_iterate(pop3_store->engine, fi[0]->cmd) > 0)
				;
			camel_pop3_engine_command_free(pop3_store->engine, fi[0]->cmd);
		}

		g_free(fi[0]->uid);
		g_free(fi[0]);
	}

	g_ptr_array_free(pop3_folder->uids, TRUE);
}

CamelFolder *
camel_pop3_folder_new (CamelStore *parent, CamelException *ex)
{
	CamelFolder *folder;

	d(printf("opening pop3 INBOX folder\n"));
	
	folder = CAMEL_FOLDER (camel_object_new (CAMEL_POP3_FOLDER_TYPE));
	camel_folder_construct (folder, parent, "inbox", "inbox");
	
	/* mt-ok, since we dont have the folder-lock for new() */
	camel_folder_refresh_info (folder, ex);/* mt-ok */
	if (camel_exception_is_set (ex)) {
		camel_object_unref (CAMEL_OBJECT (folder));
		folder = NULL;
	}
	
	return folder;
}

static CamelPOP3FolderInfo *
id_to_fi(CamelPOP3Folder *folder, guint32 id)
{
	int i;
	CamelPOP3FolderInfo **fi = (CamelPOP3FolderInfo **)folder->uids->pdata;
	int len = folder->uids->len;

	for (i=0;i<len;i++, fi++)
		if (fi[0]->id == id)
			return fi[0];

	return NULL;
}

static CamelPOP3FolderInfo *
uid_to_fi(CamelPOP3Folder *folder, const char *uid)
{
	int i;
	CamelPOP3FolderInfo **fi = (CamelPOP3FolderInfo **)folder->uids->pdata;
	int len = folder->uids->len;

	for (i=0;i<len;i++,fi++)
		if (fi[0]->uid && strcmp(fi[0]->uid, uid) == 0)
			return fi[0];

	return NULL;
}

static int
fi_to_index(CamelPOP3Folder *folder, CamelPOP3FolderInfo *fin)
{
	int i;
	CamelPOP3FolderInfo **fi = (CamelPOP3FolderInfo **)folder->uids->pdata;
	int len = folder->uids->len;

	for (i=0;i<len;i++,fi++)
		if (fi[0] == fin)
			return i;

	return -1;
}

/* create a uid from md5 of 'top' output */
static void
cmd_builduid(CamelPOP3Engine *pe, CamelPOP3Stream *stream, void *data)
{
	CamelPOP3FolderInfo *fi = data;
	MD5Context md5;
	unsigned char *start;
	unsigned int len;
	unsigned char digest[16];
	int ret;

	/* TODO; somehow work out the limit and use that for proper progress reporting
	   We need a pointer to the folder perhaps? */
	camel_operation_progress_count(NULL, fi->id);

	md5_init(&md5);
	do {
		ret = camel_pop3_stream_getd(stream, &start, &len);
		if (ret >= 0)
			md5_update(&md5, start, len);
	} while (ret > 0);
	md5_final(&md5, digest);
	fi->uid = base64_encode_simple (digest, 16);

	d(printf("building uid for id '%d' = '%s'\n", fi->id, fi->uid));
}

static void
cmd_list(CamelPOP3Engine *pe, CamelPOP3Stream *stream, void *data)
{
	int ret;
	unsigned int len, id, size;
	unsigned char *line;
	CamelFolder *folder = data;
	CamelPOP3Store *pop3_store = CAMEL_POP3_STORE (folder->parent_store);
	CamelPOP3FolderInfo *fi;

	do {
		ret = camel_pop3_stream_line(stream, &line, &len);
		if (ret>=0) {
			if (sscanf(line, "%u %u", &id, &size) == 2) {
				fi = g_malloc0(sizeof(*fi));
				fi->size = size;
				fi->id = id;
				if ((pop3_store->engine->capa & CAMEL_POP3_CAP_UIDL) == 0)
					fi->cmd = camel_pop3_engine_command_new(pe, CAMEL_POP3_COMMAND_MULTI, cmd_builduid, fi, "TOP %u 0\r\n", id);
				g_ptr_array_add(((CamelPOP3Folder *)folder)->uids, fi);
			}
		}
	} while (ret>0);
}

static void
cmd_uidl(CamelPOP3Engine *pe, CamelPOP3Stream *stream, void *data)
{
	int ret;
	unsigned int len;
	unsigned char *line;
	char uid[1025];
	unsigned int id, i=0;
	CamelPOP3FolderInfo *fi;
	CamelPOP3Folder *folder = data;
	
	do {
		ret = camel_pop3_stream_line(stream, &line, &len);
		if (ret>=0) {			
			if (strlen(line) > 1024)
				line[1024] = 0;
			if (sscanf(line, "%u %s", &id, uid) == 2) {
				fi = id_to_fi(folder, id);
				if (fi) {
					/* fixme: dreadfully inefficient */
					i = fi_to_index(folder, fi);
					camel_operation_progress(NULL, (i+1) * 100 / folder->uids->len);
					fi->uid = g_strdup(uid);
				} else {
					g_warning("ID %u (uid: %s) not in previous LIST output", id, uid);
				}
			}
		}
	} while (ret>0);
}

static void 
pop3_refresh_info (CamelFolder *folder, CamelException *ex)
{
	CamelPOP3Store *pop3_store = CAMEL_POP3_STORE (folder->parent_store);
	CamelPOP3Folder *pop3_folder = (CamelPOP3Folder *) folder;
	CamelPOP3Command *pcl, *pcu = NULL;
	int i;

	camel_operation_start (NULL, _("Retrieving POP summary"));

	pop3_folder->uids = g_ptr_array_new ();

	pcl = camel_pop3_engine_command_new(pop3_store->engine, CAMEL_POP3_COMMAND_MULTI, cmd_list, folder, "LIST\r\n");
	if (pop3_store->engine->capa & CAMEL_POP3_CAP_UIDL) {
		pcu = camel_pop3_engine_command_new(pop3_store->engine, CAMEL_POP3_COMMAND_MULTI, cmd_uidl, folder, "UIDL\r\n");
	}
	while ((i = camel_pop3_engine_iterate(pop3_store->engine, NULL)) > 0)
		;

	if (i == -1) {
		if (errno == EINTR)
			camel_exception_setv(ex, CAMEL_EXCEPTION_USER_CANCEL, _("User cancelled"));
		else
			camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, _("Cannot get POP summary: %s"), strerror(errno));
	}

	/* TODO: check every id has a uid & commands returned OK too? */

	/* Free any commands we created along the way */
	if (pop3_store->engine->capa & CAMEL_POP3_CAP_UIDL) {
		camel_pop3_engine_command_free(pop3_store->engine, pcu);
	} else {
		for (i=0;i<pop3_folder->uids->len;i++) {
			CamelPOP3FolderInfo *fi = pop3_folder->uids->pdata[i];
			if (fi->cmd) {
				camel_pop3_engine_command_free(pop3_store->engine, fi->cmd);
				fi->cmd = NULL;
			}
		}
	}

	camel_operation_end (NULL);
	return;
}

static void
pop3_sync (CamelFolder *folder, gboolean expunge, CamelException *ex)
{
	CamelPOP3Folder *pop3_folder;
	CamelPOP3Store *pop3_store;
	int i;
	CamelPOP3FolderInfo *fi;

	if (!expunge)
		return;

	pop3_folder = CAMEL_POP3_FOLDER (folder);
	pop3_store = CAMEL_POP3_STORE (folder->parent_store);

	camel_operation_start(NULL, _("Expunging deleted messages"));
	
	for (i = 0; i < pop3_folder->uids->len; i++) {
		fi = pop3_folder->uids->pdata[i];
		/* busy already?  wait for that to finish first */
		if (fi->cmd) {
			while (camel_pop3_engine_iterate(pop3_store->engine, fi->cmd) > 0)
				;
			camel_pop3_engine_command_free(pop3_store->engine, fi->cmd);
			fi->cmd = NULL;
		}

		if (fi->flags & CAMEL_MESSAGE_DELETED) {
			fi->cmd = camel_pop3_engine_command_new(pop3_store->engine, 0, NULL, NULL, "DELE %u\r\n", fi->id);

			/* also remove from cache */
			if (pop3_store->cache && fi->uid)
				camel_data_cache_remove(pop3_store->cache, "cache", fi->uid, NULL);
		}
	}

	for (i = 0; i < pop3_folder->uids->len; i++) {
		fi = pop3_folder->uids->pdata[i];
		/* wait for delete commands to finish */
		if (fi->cmd) {
			while (camel_pop3_engine_iterate(pop3_store->engine, fi->cmd) > 0)
				;
			camel_pop3_engine_command_free(pop3_store->engine, fi->cmd);
			fi->cmd = NULL;
		}
		camel_operation_progress(NULL, (i+1) * 100 / pop3_folder->uids->len);
	}

	camel_operation_end(NULL);

	camel_pop3_store_expunge (pop3_store, ex);
}

static void
cmd_tocache(CamelPOP3Engine *pe, CamelPOP3Stream *stream, void *data)
{
	CamelPOP3FolderInfo *fi = data;
	char buffer[2048];
	int w = 0, n;

	/* What if it fails? */

	/* We write an '*' to the start of the stream to say its not complete yet */
	/* This should probably be part of the cache code */
	if ((n = camel_stream_write(fi->stream, "*", 1)) == -1)
		goto done;

	while ((n = camel_stream_read((CamelStream *)stream, buffer, sizeof(buffer))) > 0) {
		n = camel_stream_write(fi->stream, buffer, n);
		if (n == -1)
			break;

		w += n;
		if (w > fi->size)
			w = fi->size;
		camel_operation_progress(NULL, (w * 100) / fi->size);
	}

	/* it all worked, output a '#' to say we're a-ok */
	if (n != -1) {
		camel_stream_reset(fi->stream);
		n = camel_stream_write(fi->stream, "#", 1);
	}
done:
	if (n == -1) {
		fi->err = errno;
		g_warning("POP3 retrieval failed: %s", strerror(errno));
	} else {
		fi->err = 0;
	}
	
	camel_object_unref((CamelObject *)fi->stream);
	fi->stream = NULL;
}

static CamelMimeMessage *
pop3_get_message (CamelFolder *folder, const char *uid, CamelException *ex)
{
	CamelMimeMessage *message = NULL;
	CamelPOP3Store *pop3_store = CAMEL_POP3_STORE (folder->parent_store);
	CamelPOP3Folder *pop3_folder = (CamelPOP3Folder *)folder;
	CamelPOP3Command *pcr;
	CamelPOP3FolderInfo *fi;
	char buffer[1];
	int ok, i, last;
	CamelStream *stream = NULL;

	fi = uid_to_fi(pop3_folder, uid);
	if (fi == NULL) {
		camel_exception_setv (ex, CAMEL_EXCEPTION_FOLDER_INVALID_UID,
				      _("No message with uid %s"), uid);
		return NULL;
	}

	/* Sigh, most of the crap in this function is so that the cancel button
	   returns the proper exception code.  Sigh. */

	camel_operation_start_transient(NULL, _("Retrieving POP message %d"), fi->id);

	/* If we have an oustanding retrieve message running, wait for that to complete
	   & then retrieve from cache, otherwise, start a new one, and similar */

	if (fi->cmd != NULL) {
		while ((i = camel_pop3_engine_iterate(pop3_store->engine, fi->cmd)) > 0)
			;

		if (i == -1)
			fi->err = errno;

		/* getting error code? */
		ok = fi->cmd->state == CAMEL_POP3_COMMAND_DATA;
		camel_pop3_engine_command_free(pop3_store->engine, fi->cmd);
		fi->cmd = NULL;

		if (fi->err != 0) {
			if (fi->err == EINTR)
				camel_exception_setv(ex, CAMEL_EXCEPTION_USER_CANCEL, _("User cancelled"));
			else
				camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, _("Cannot get message %s: %s"), uid, strerror(fi->err));
			goto fail;
		}
	}
	
	/* check to see if we have safely written flag set */
	if (pop3_store->cache == NULL
	    || (stream = camel_data_cache_get(pop3_store->cache, "cache", fi->uid, NULL)) == NULL
	    || camel_stream_read(stream, buffer, 1) != 1
	    || buffer[0] != '#') {

		/* Initiate retrieval, if disk backing fails, use a memory backing */
		if (pop3_store->cache == NULL
		    || (stream = camel_data_cache_add(pop3_store->cache, "cache", fi->uid, NULL)) == NULL)
			stream = camel_stream_mem_new();

		/* ref it, the cache storage routine unref's when done */
		camel_object_ref((CamelObject *)stream);
		fi->stream = stream;
		fi->err = EIO;
		pcr = camel_pop3_engine_command_new(pop3_store->engine, CAMEL_POP3_COMMAND_MULTI, cmd_tocache, fi, "RETR %u\r\n", fi->id);

		/* Also initiate retrieval of some of the following messages, assume we'll be receiving them */
		if (pop3_store->cache != NULL) {
			/* This should keep track of the last one retrieved, also how many are still
			   oustanding incase of random access on large folders */
			i = fi_to_index(pop3_folder, fi)+1;
			last = MIN(i+10, pop3_folder->uids->len);
			for (;i<last;i++) {
				CamelPOP3FolderInfo *pfi = pop3_folder->uids->pdata[i];
				
				if (pfi->uid && pfi->cmd == NULL) {
					pfi->stream = camel_data_cache_add(pop3_store->cache, "cache", pfi->uid, NULL);
					if (pfi->stream) {
						pfi->err = EIO;
						pfi->cmd = camel_pop3_engine_command_new(pop3_store->engine, CAMEL_POP3_COMMAND_MULTI,
											 cmd_tocache, pfi, "RETR %u\r\n", pfi->id);
					}
				}
			}
		}

		/* now wait for the first one to finish */
		while ((i = camel_pop3_engine_iterate(pop3_store->engine, pcr)) > 0)
			;

		if (i == -1)
			fi->err = errno;

		/* getting error code? */
		ok = pcr->state == CAMEL_POP3_COMMAND_DATA;
		camel_pop3_engine_command_free(pop3_store->engine, pcr);
		camel_stream_reset(stream);

		/* Check to see we have safely written flag set */
		if (fi->err != 0) {
			if (fi->err == EINTR)
				camel_exception_setv(ex, CAMEL_EXCEPTION_USER_CANCEL, _("User cancelled"));
			else
				camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, _("Cannot get message %s: %s"), uid, strerror(fi->err));
			goto done;
		}

		if (camel_stream_read(stream, buffer, 1) != 1
		    || buffer[0] != '#') {
			camel_exception_setv(ex, CAMEL_EXCEPTION_FOLDER_INVALID_UID,
					     _("Cannot get message %s: %s"), uid, _("Unknown reason"));
			goto done;
		}
	}

	message = camel_mime_message_new ();
	if (camel_data_wrapper_construct_from_stream((CamelDataWrapper *)message, stream) == -1) {
		if (errno == EINTR)
			camel_exception_setv(ex, CAMEL_EXCEPTION_USER_CANCEL, _("User cancelled"));
		else
			camel_exception_setv(ex, CAMEL_EXCEPTION_SYSTEM, _("Cannot get message %s: %s"), uid, strerror(errno));
		camel_object_unref((CamelObject *)message);
		message = NULL;
	}
done:
	camel_object_unref((CamelObject *)stream);
fail:
	camel_operation_end(NULL);

	return message;
}

static void
pop3_set_message_flags (CamelFolder *folder, const char *uid, guint32 flags, guint32 set)
{
	CamelPOP3Folder *pop3_folder = CAMEL_POP3_FOLDER (folder);
	CamelPOP3FolderInfo *fi;

	fi = uid_to_fi(pop3_folder, uid);
	if (fi)
		fi->flags = (fi->flags & ~flags) | (set & flags);
}

static gint
pop3_get_message_count (CamelFolder *folder)
{
	CamelPOP3Folder *pop3_folder = CAMEL_POP3_FOLDER (folder);
	
	return pop3_folder->uids->len;
}

static GPtrArray *
pop3_get_uids (CamelFolder *folder)
{
	CamelPOP3Folder *pop3_folder = CAMEL_POP3_FOLDER (folder);
	GPtrArray *uids = g_ptr_array_new();
	CamelPOP3FolderInfo **fi = (CamelPOP3FolderInfo **)pop3_folder->uids->pdata;
	int i;

	for (i=0;i<pop3_folder->uids->len;i++,fi++) {
		if (fi[0]->uid)
			g_ptr_array_add(uids, fi[0]->uid);
	}
	
	return uids;
}