/*
 * accelerometers.c
 *
 * Accelerometer stuff
 *
 * (c) 2008 Thomas White <taw27@srcf.ucam.org>
 *
 * This file is part of OpenMooCow - accelerometer moobox simulator
 *
 * OpenMooCow 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.
 *
 * OpenMooCow 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 OpenMooCow.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

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

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>

#include "types.h"
#include "audio.h"

struct input_event {
	struct timeval time;
	uint16_t type;
	uint16_t code;
	int32_t value;
};
#define EV_SYN (0x00)
#define EV_REL (0x02)
#define SYN_REPORT (0x00)
#define REL_X (0x00)
#define REL_Y (0x01)
#define REL_Z (0x02)

AccelHandle *accelerometer_open() {

	AccelHandle *accel;
	
	accel = malloc(sizeof(AccelHandle));
	if ( accel == NULL ) return NULL;
	
	accel->fh1 = fopen("/dev/input/event2", "rb");
	accel->fh2 = fopen("/dev/input/event3", "rb");
	accel->ax = 0;
	accel->ay = 0;
	accel->az = 0;
	accel->bx = 0;
	accel->by = 0;
	accel->bz = 0;
	
	return accel;

}

void accelerometer_update(AccelHandle *accel) {

	if ( accel->fh1 != NULL ) {
	
		int i;
		
		for ( i=1; i<=4; i++ ) {
		
			struct input_event ev;
			size_t rval;
		
			rval = fread(&ev, sizeof(struct input_event), 1, accel->fh1);
			if ( rval != 1 ) {
				fprintf(stderr, "Couldn't read accelerometer data");
				return;
			}
	
			if ( ev.type == EV_REL ) {
				if ( ev.code == REL_X ) {
					accel->lax = ev.value;
				}
				if ( ev.code == REL_Y ) {
					accel->lay = ev.value;
				}
				if ( ev.code == REL_Z ) {
					accel->laz = ev.value;
				}
			}
	
			if ( ev.type == EV_SYN ) {
				if ( ev.code == SYN_REPORT ) {
					accel->ax = accel->lax;
					accel->ay = accel->lay;
					accel->az = accel->laz;
					accel->lval = accel->ax + accel->ay;
				}
			}
		
		}
		
	}
	
	if ( accel->fh2 != NULL ) {
	
		struct input_event ev;
		size_t rval;
		
		rval = fread(&ev, sizeof(struct input_event), 1, accel->fh2);
		if ( rval != 1 ) {
			fprintf(stderr, "Couldn't read accelerometer data");
			return;
		}
	
		if ( ev.type == EV_REL ) {
			if ( ev.code == REL_X ) {
				accel->lbx = ev.value;
			}
			if ( ev.code == REL_Y ) {
				accel->lby = ev.value;
			}
			if ( ev.code == REL_Z ) {
				accel->lbz = ev.value;
			}
		}
	
		if ( ev.type == EV_SYN ) {
			if ( ev.code == SYN_REPORT ) {
				accel->bx = accel->lbx;
				accel->by = accel->lby;
				accel->bz = accel->lbz;
			}
		}
	}


}

/* The accelerometer work thread */
static void *accel_work(void *data) {

	AccelHandle *accel;
	int pos = 0;
	
	accel = accelerometer_open();
	audio_setup();
	
	while ( 1 ) {
	
		accelerometer_update(accel);
		
		if ( accel->lval > 1000 ) pos = 1000;
		if ( (accel->lval < -1000) && (pos == 1000) ) {
			pos = 0;
			audio_trigger_moo();
		}
		
		usleep(25000);
	}
	
	audio_shutdown();
	
	return NULL;

}

void accelerometer_start() {

	GThread *work_thread;
	
	work_thread = g_thread_create(accel_work, NULL, TRUE, NULL);	
	
}