/***************************************************************************\
*                                                                           *
*  BitlBee - An IRC to IM gateway                                           *
*  libpurple module - File transfer stuff                                   *
*                                                                           *
*  Copyright 2009-2010 Wilmer van der Gaast <wilmer@gaast.net>              *
*                                                                           *
*  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.,  *
*  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.              *
*                                                                           *
\***************************************************************************/

/* This code tries to do direct file transfers, i.e. without caching the file
   locally on disk first. Since libpurple can only do this since version 2.6.0
   and even then very unreliably (and not with all IM modules), I'm canning
   this code for now. */

#include "bitlbee.h"
#include "bpurple.h"

#include <stdarg.h>

#include <glib.h>
#include <purple.h>

struct prpl_xfer_data {
	PurpleXfer *xfer;
	file_transfer_t *ft;
	gint ready_timer;
	char *buf;
	int buf_len;
};

static file_transfer_t *next_ft;

struct im_connection *purple_ic_by_pa(PurpleAccount *pa);

/* Glorious hack: We seem to have to remind at least some libpurple plugins
   that we're ready because this info may get lost if we give it too early.
   So just do it ten times a second. :-/ */
static gboolean prplcb_xfer_write_request_cb(gpointer data, gint fd, b_input_condition cond)
{
	struct prpl_xfer_data *px = data;

	purple_xfer_ui_ready(px->xfer);

	return purple_xfer_get_type(px->xfer) == PURPLE_XFER_RECEIVE;
}

static gboolean prpl_xfer_write_request(struct file_transfer *ft)
{
	struct prpl_xfer_data *px = ft->data;

	px->ready_timer = b_timeout_add(100, prplcb_xfer_write_request_cb, px);
	return TRUE;
}

static gboolean prpl_xfer_write(struct file_transfer *ft, char *buffer, unsigned int len)
{
	struct prpl_xfer_data *px = ft->data;

	px->buf = g_memdup(buffer, len);
	px->buf_len = len;

	//purple_xfer_ui_ready( px->xfer );
	px->ready_timer = b_timeout_add(0, prplcb_xfer_write_request_cb, px);

	return TRUE;
}

static void prpl_xfer_accept(struct file_transfer *ft)
{
	struct prpl_xfer_data *px = ft->data;

	purple_xfer_request_accepted(px->xfer, NULL);
	prpl_xfer_write_request(ft);
}

static void prpl_xfer_canceled(struct file_transfer *ft, char *reason)
{
	struct prpl_xfer_data *px = ft->data;

	purple_xfer_request_denied(px->xfer);
}

static gboolean prplcb_xfer_new_send_cb(gpointer data, gint fd, b_input_condition cond)
{
	PurpleXfer *xfer = data;
	struct im_connection *ic = purple_ic_by_pa(xfer->account);
	struct prpl_xfer_data *px = g_new0(struct prpl_xfer_data, 1);
	PurpleBuddy *buddy;
	const char *who;

	buddy = purple_find_buddy(xfer->account, xfer->who);
	who = buddy ? purple_buddy_get_name(buddy) : xfer->who;

	/* TODO(wilmer): After spreading some more const goodness in BitlBee,
	   remove the evil cast below. */
	px->ft = imcb_file_send_start(ic, (char *) who, xfer->filename, xfer->size);
	px->ft->data = px;
	px->xfer = data;
	px->xfer->ui_data = px;

	px->ft->accept = prpl_xfer_accept;
	px->ft->canceled = prpl_xfer_canceled;
	px->ft->write_request = prpl_xfer_write_request;

	return FALSE;
}

static void prplcb_xfer_new(PurpleXfer *xfer)
{
	if (purple_xfer_get_type(xfer) == PURPLE_XFER_RECEIVE) {
		/* This should suppress the stupid file dialog. */
		purple_xfer_set_local_filename(xfer, "/tmp/wtf123");

		/* Sadly the xfer struct is still empty ATM so come back after
		   the caller is done. */
		b_timeout_add(0, prplcb_xfer_new_send_cb, xfer);
	} else {
		struct prpl_xfer_data *px = g_new0(struct prpl_xfer_data, 1);

		px->ft = next_ft;
		px->ft->data = px;
		px->xfer = xfer;
		px->xfer->ui_data = px;

		purple_xfer_set_filename(xfer, px->ft->file_name);
		purple_xfer_set_size(xfer, px->ft->file_size);

		next_ft = NULL;
	}
}

static void prplcb_xfer_progress(PurpleXfer *xfer, double percent)
{
	fprintf(stderr, "prplcb_xfer_dbg 0x%p %f\n", xfer, percent);
}

static void prplcb_xfer_dbg(PurpleXfer *xfer)
{
	fprintf(stderr, "prplcb_xfer_dbg 0x%p\n", xfer);
}

static gssize prplcb_xfer_write(PurpleXfer *xfer, const guchar *buffer, gssize size)
{
	struct prpl_xfer_data *px = xfer->ui_data;
	gboolean st;

	fprintf(stderr, "xfer_write %d %d\n", size, px->buf_len);

	b_event_remove(px->ready_timer);
	px->ready_timer = 0;

	st = px->ft->write(px->ft, (char *) buffer, size);

	if (st && xfer->bytes_remaining == size) {
		imcb_file_finished(px->ft);
	}

	return st ? size : 0;
}

gssize prplcb_xfer_read(PurpleXfer *xfer, guchar **buffer, gssize size)
{
	struct prpl_xfer_data *px = xfer->ui_data;

	fprintf(stderr, "xfer_read %d %d\n", size, px->buf_len);

	if (px->buf) {
		*buffer = px->buf;
		px->buf = NULL;

		px->ft->write_request(px->ft);

		return px->buf_len;
	}

	return 0;
}

PurpleXferUiOps bee_xfer_uiops =
{
	prplcb_xfer_new,           /* new_xfer */
	prplcb_xfer_dbg,           /* destroy */
	prplcb_xfer_dbg,           /* add_xfer */
	prplcb_xfer_progress,      /* update_progress */
	prplcb_xfer_dbg,           /* cancel_local */
	prplcb_xfer_dbg,           /* cancel_remote */
	prplcb_xfer_write,         /* ui_write */
	prplcb_xfer_read,          /* ui_read */
	prplcb_xfer_dbg,           /* data_not_sent */
};

static gboolean prplcb_xfer_send_cb(gpointer data, gint fd, b_input_condition cond);

void purple_transfer_request(struct im_connection *ic, file_transfer_t *ft, char *handle)
{
	struct purple_data *pd = ic->proto_data;
	struct prpl_xfer_data *px;

	/* xfer_new() will pick up this variable. It's a hack but we're not
	   multi-threaded anyway. */
	next_ft = ft;
	serv_send_file(purple_account_get_connection(pd->account), handle,
	               ft->file_name);

	ft->write = prpl_xfer_write;

	px = ft->data;
	imcb_file_recv_start(ft);

	px->ready_timer = b_timeout_add(100, prplcb_xfer_send_cb, px);
}

static gboolean prplcb_xfer_send_cb(gpointer data, gint fd, b_input_condition cond)
{
	struct prpl_xfer_data *px = data;

	if (px->ft->status & FT_STATUS_TRANSFERRING) {
		fprintf(stderr, "The ft, it is ready...\n");
		px->ft->write_request(px->ft);

		return FALSE;
	}

	return TRUE;
}
