/* $Id: pop3.c,v 1.11 2011/02/21 01:31:18 khorben Exp $ */
/* Copyright (c) 2011 Pierre Pronchery <khorben@defora.org> */
/* This file is part of DeforaOS Desktop Mailer */
/* 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 3 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, see <http://www.gnu.org/licenses/>. */



#include <sys/socket.h>
#include <stdlib.h>
#ifdef DEBUG
# include <stdio.h>
#endif
#include <string.h>
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "Mailer.h"


/* POP3 */
/* private */
/* types */
typedef struct _POP3
{
	int fd;
	guint source;

	GIOChannel * channel;
	char * rd_buf;
	size_t rd_buf_cnt;
	guint rd_source;
	char * wr_buf;
	size_t wr_buf_cnt;
	guint wr_source;

	AccountFolder inbox;
	AccountFolder trash;
	GtkTextBuffer * tbuf;
} POP3;


/* variables */
static char const _pop3_type[] = "POP3";
static char const _pop3_name[] = "POP3 server";

static AccountConfig _pop3_config[] =
{
	{ "username",	"Username",		ACT_STRING,	NULL },
	{ "password",	"Password",		ACT_PASSWORD,	NULL },
	{ "hostname",	"Server hostname",	ACT_STRING,	NULL },
	{ "port",	"Server port",		ACT_UINT16,	NULL },
	{ "ssl",	"Use SSL",		ACT_BOOLEAN,	NULL },
	{ "delete",	"Delete read mails on server",
						ACT_BOOLEAN,	NULL },
	{ NULL,		NULL,			ACT_NONE,	NULL }
};

static const AccountFolder _pop3_folder_inbox =
{
	AFT_INBOX, "Inbox", NULL, NULL
};

static const AccountFolder _pop3_folder_trash =
{
	AFT_TRASH, "Trash", NULL, NULL
};


/* prototypes */
static int _pop3_init(AccountPlugin * plugin, GtkTreeStore * store,
		GtkTreeIter * parent, GtkTextBuffer * buffer);
static int _pop3_destroy(AccountPlugin * plugin);
static GtkTextBuffer * _pop3_select(AccountPlugin * plugin,
		AccountFolder * folder, AccountMessage * message);

/* callbacks */
static gboolean _on_idle(gpointer data);
static gboolean _on_watch_can_read(GIOChannel * source, GIOCondition condition,
		gpointer data);
static gboolean _on_watch_can_write(GIOChannel * source, GIOCondition condition,
		gpointer data);


/* public */
/* variables */
AccountPlugin account_plugin =
{
	NULL,
	_pop3_type,
	_pop3_name,
	NULL,
	_pop3_config,
	_pop3_init,
	_pop3_destroy,
	_pop3_select,
	NULL,
	NULL
};


/* private */
/* functions */
/* pop3_init */
static int _pop3_init(AccountPlugin * plugin, GtkTreeStore * store,
		GtkTreeIter * parent, GtkTextBuffer * buffer)
{
	POP3 * pop3;
	GdkPixbuf * pixbuf;
	GtkTreeIter iter;

	if((pop3 = malloc(sizeof(*pop3))) == NULL)
		return -1;
	plugin->priv = pop3;
	pop3->fd = -1;
	pop3->source = g_idle_add(_on_idle, plugin);
	pop3->channel = NULL;
	pop3->rd_buf = NULL;
	pop3->rd_buf_cnt = 0;
	pop3->rd_source = 0;
	pop3->wr_buf = NULL;
	pop3->wr_buf_cnt = 0;
	pop3->wr_source = 0;
	memcpy(&pop3->inbox, &_pop3_folder_inbox, sizeof(pop3->inbox));
	memcpy(&pop3->trash, &_pop3_folder_trash, sizeof(pop3->trash));
	pop3->tbuf = gtk_text_buffer_new(NULL);
	/* inbox */
	pixbuf = gtk_icon_theme_load_icon(plugin->helper->theme, "mailer-inbox",
			16, 0, NULL);
	gtk_tree_store_append(store, &iter, parent);
	gtk_tree_store_set(store, &iter, MF_COL_ACCOUNT, NULL, MF_COL_FOLDER,
			&pop3->inbox, MF_COL_ICON, pixbuf, MF_COL_NAME,
			pop3->inbox.name, -1);
	/* trash */
	pixbuf = gtk_icon_theme_load_icon(plugin->helper->theme,
			"stock_trash_full", 16, 0, NULL);
	gtk_tree_store_append(store, &iter, parent);
	gtk_tree_store_set(store, &iter, MF_COL_ACCOUNT, NULL, MF_COL_FOLDER,
			&pop3->trash, MF_COL_ICON, pixbuf, MF_COL_NAME,
			pop3->trash.name, -1);
	return 0;
}


/* pop3_destroy */
static int _pop3_destroy(AccountPlugin * plugin)
{
	POP3 * pop3 = plugin->priv;
	GError * error = NULL;

#ifdef DEBUG
	fprintf(stderr, "DEBUG: %s()\n", __func__);
#endif
	if(pop3 == NULL) /* XXX _pop3_destroy() may be called uninitialized */
		return 0;
	if(pop3->rd_source != 0)
		g_source_remove(pop3->rd_source);
	free(pop3->rd_buf);
	if(pop3->wr_source != 0)
		g_source_remove(pop3->wr_source);
	free(pop3->wr_buf);
	if(pop3->source != 0)
		g_source_remove(pop3->source);
	if(pop3->channel != NULL)
	{
		g_io_channel_shutdown(pop3->channel, TRUE, &error);
		g_io_channel_unref(pop3->channel);
	}
	if(pop3->fd >= 0)
		close(pop3->fd);
	free(pop3);
	return 0;
}


/* pop3_select */
static GtkTextBuffer * _pop3_select(AccountPlugin * plugin,
		AccountFolder * folder, AccountMessage * message)
{
	POP3 * pop3 = plugin->priv;

#ifdef DEBUG
	fprintf(stderr, "DEBUG: %s()\n", __func__);
#endif
	return pop3->tbuf;
}


/* callbacks */
/* on_idle */
static gboolean _idle_connect(AccountPlugin * plugin);
static gboolean _idle_channel(AccountPlugin * plugin);

static gboolean _on_idle(gpointer data)
{
	gboolean ret = FALSE;
	AccountPlugin * plugin = data;
	POP3 * pop3 = plugin->priv;

#ifdef DEBUG
	fprintf(stderr, "DEBUG: %s()\n", __func__);
#endif
	if(pop3->fd < 0)
		ret = _idle_connect(plugin);
	else if(pop3->channel == NULL)
		ret = _idle_channel(plugin);
	if(ret == FALSE)
		pop3->source = 0;
	return ret;
}

static gboolean _idle_connect(AccountPlugin * plugin)
{
	POP3 * pop3 = plugin->priv;
	char const * p;
	struct hostent * he;
	unsigned short port;
	struct sockaddr_in sa;

#ifdef DEBUG
	fprintf(stderr, "DEBUG: %s()\n", __func__);
#endif
	/* FIXME report errors */
	if((p = plugin->config[2].value) == NULL)
		return FALSE;
	if((he = gethostbyname(p)) == NULL)
	{
		plugin->helper->error(NULL, hstrerror(h_errno), 1);
		return FALSE;
	}
	if((p = plugin->config[3].value) == NULL)
		return FALSE;
	port = (unsigned long)p;
	if((pop3->fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
	{
		plugin->helper->error(NULL, strerror(errno), 1);
		return FALSE;
	}
	sa.sin_family = AF_INET;
	sa.sin_port = htons(port);
	sa.sin_addr.s_addr = *((uint32_t*)he->h_addr_list[0]);
#ifdef DEBUG
	fprintf(stderr, "DEBUG: %s() connecting to %s:%u\n", __func__,
			inet_ntoa(sa.sin_addr), port);
#endif
	if(connect(pop3->fd, (struct sockaddr *)&sa, sizeof(sa)) != 0)
	{
		plugin->helper->error(NULL, strerror(errno), 1);
		close(pop3->fd);
		pop3->fd = -1;
		return FALSE;
	}
	return TRUE;
}

static gboolean _idle_channel(AccountPlugin * plugin)
{
	POP3 * pop3 = plugin->priv;
	GError * error = NULL;

	pop3->channel = g_io_channel_unix_new(pop3->fd);
	g_io_channel_set_encoding(pop3->channel, NULL, &error);
	g_io_channel_set_buffered(pop3->channel, FALSE);
	pop3->rd_source = g_io_add_watch(pop3->channel, G_IO_IN,
			_on_watch_can_read, plugin);
	return TRUE;
}


/* on_watch_can_read */
static gboolean _on_watch_can_read(GIOChannel * source, GIOCondition condition,
		gpointer data)
{
	AccountPlugin * plugin = data;
	POP3 * pop3 = plugin->priv;
	char * p;
	gsize cnt = 0;
	GError * error = NULL;
	GIOStatus status;

	if(condition != G_IO_IN || source != pop3->channel)
		return FALSE; /* should not happen */
	if((p = realloc(pop3->rd_buf, pop3->rd_buf_cnt + 256)) == NULL)
		return TRUE; /* XXX retries immediately (delay?) */
	pop3->rd_buf = p;
	status = g_io_channel_read_chars(source,
			&pop3->rd_buf[pop3->rd_buf_cnt], 256, &cnt, &error);
#ifdef DEBUG
	fprintf(stderr, "%s", "DEBUG: POP3 SERVER: ");
	fwrite(&pop3->rd_buf[pop3->rd_buf_cnt], sizeof(*p), cnt, stderr);
#endif
	pop3->rd_buf_cnt += cnt;
	switch(status)
	{
		case G_IO_STATUS_NORMAL:
			break;
		case G_IO_STATUS_ERROR:
			plugin->helper->error(NULL, error->message, 1);
		case G_IO_STATUS_EOF:
		default: /* XXX find a way to recover */
			pop3->rd_source = 0;
			return FALSE;
	}
	/* FIXME implement the rest */
	return TRUE;
}


/* on_watch_can_write */
static gboolean _on_watch_can_write(GIOChannel * source, GIOCondition condition,
		gpointer data)
{
	AccountPlugin * plugin = data;
	POP3 * pop3 = plugin->priv;

	/* FIXME implement */
	pop3->wr_source = 0;
	return FALSE;
}