/*****************************************************************************
 *
 * grail - Gesture Recognition And Instantiation Library
 *
 * Copyright (C) 2010 Canonical Ltd.
 * Copyright (C) 2010 Henrik Rydberg <rydberg@bitmath.org>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 ****************************************************************************/

#include "grail-recognizer.h"
#include <math.h>

static const int TAP_BEGIN = 0;
static const int TAP_END = 1;
static const int TAP_CANCEL = 2;

static const int TAP_MIN_GAP_MS = 25;
static const int TAP_MAX_GAP_MS = 300;

static const int fm_mask = 0x03;

int gru_tapping(struct grail *ge,
		const struct touch_frame *frame)
{
	struct gesture_recognizer *gru = ge->gru;
	struct tapping_model *state = &gru->tapping;
	struct move_model *move = &gru->move;
	grail_prop_t prop[DIM_GRAIL_PROP];
	if (move->ntouch) {
		if (state->status == TAP_CANCEL)
			return 0;
		state->status = TAP_BEGIN;
		if (!state->ntouch)
			state->start = move->time;
		if (move->ntouch > state->ntouch) {
			state->ntouch = move->ntouch;
			if (state->active) {
				gin_gid_discard(ge, state->gid);
				state->active = 0;
			}
		}
		if (!state->active) {
			int type = GRAIL_TYPE_TAP1 + state->ntouch - 1;
			state->gid = gin_gid_begin(ge, type, PRIO_TAP, frame);
			state->active = 1;
		}
	} else if (state->status == TAP_BEGIN && state->ntouch) {
		state->status = TAP_END;
	} else {
		state->status = TAP_BEGIN;
		state->ntouch = 0;
		return 0;
	}
	if (state->ntouch < 1 || state->ntouch > 5)
		state->status = TAP_CANCEL;
	if (move->time - state->start > TAP_MAX_GAP_MS)
		state->status = TAP_CANCEL;
	if (state->status == TAP_END &&
	    move->time - state->start < TAP_MIN_GAP_MS)
		state->status = TAP_CANCEL;
	if (move->active & fm_mask)
		state->status = TAP_CANCEL;
	if (state->status == TAP_CANCEL) {
		if (state->active) {
			gin_gid_discard(ge, state->gid);
			state->active = 0;
		}
		state->ntouch = 0;
		return 0;
	}
	if (state->status != TAP_END ||
	    move->time - state->start < TAP_MIN_GAP_MS)
		return 0;
	prop[GRAIL_PROP_TAP_DT] = move->time - state->start;
	gin_gid_event(ge, state->gid,
		      move->fm[FM_X].value, move->fm[FM_Y].value, state->ntouch,
		      prop, 1, 1);
	state->status = TAP_BEGIN;
	state->ntouch = 0;
	state->active = 0;
	return 1;
}