/*
 * accelerometers.c
 *
 * Accelerometer stuff
 *
 * (c) 2008-2009 Thomas White <taw@bitwiz.org.uk>
 * (c) 2008 Joachim Breitner <mail@joachim-breitner.de>
 *
 * 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 <sys/types.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <fcntl.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 EV_ABS (0x03)
#define SYN_REPORT (0x00)
#define REL_X (0x00)
#define REL_Y (0x01)
#define REL_Z (0x02)

/* Try to open the threshold sysfs file for Freerunner's accelerometers.
 * Try methods for both old and new kernels */
static FILE *accelerometer_freerunner_open_threshold(const char *mode)
{
	FILE *fh;

	/* Try 2.6.24 method */
	fh = fopen("/sys/devices/platform/lis302dl.2/threshold", mode);
	if ( fh != NULL ) {
		return fh;
	}

	/* Try 2.6.28+ method */
	fh = fopen("/sys/class/i2c-adapter/i2c-0/0-0073/lis302dl.2/threshold",
									mode);
	if ( fh != NULL ) {
		return fh;
	}

	/* Try 2.6.29-ish+ method */
	fh = fopen("/sys/devices/platform/s3c2440-i2c/i2c-adapter:i2c-0"
			"/0-0073/spi_s3c24xx_gpio.0/spi3.1/threshold", mode);
	if ( fh != NULL ) {
		return fh;
	}

	return NULL;
}

static void accelerometer_freerunner_try_threshold(AccelHandle *accel)
{
	FILE *fh;
	int rval;

	/* Save the old threshold */
	fh = accelerometer_freerunner_open_threshold("r");
	if ( fh == NULL ) {
		fprintf(stderr, "Couldn't read old accelerometer threshold.\n");
		accel->old_threshold = -1;
		return;
	}
	rval = fscanf(fh, "%i", &accel->old_threshold);
	if ( rval != 1 ) {
		/* Failed */
		fprintf(stderr, "Couldn't read old accelerometer threshold.\n");
		accel->old_threshold = -1;
	}
	printf("Old threshold was %i\n", accel->old_threshold);
	fclose(fh);

	/* Set the threshold to zero */
	fh = accelerometer_freerunner_open_threshold("w");
	if ( fh == NULL ) {
		fprintf(stderr, "Failed to disable accelerometer threshold.\n");
		return;
	}
	fprintf(fh, "0\n");
	printf("Successfully disabled accelerometer threshold.\n");
	fclose(fh);
}

static void accelerometer_freerunner_try_restore_threshold(AccelHandle *accel)
{
	FILE *fh;
	int rval;
	int new_threshold;

	if ( accel->old_threshold < 0 ) {
		printf("Not restoring threshold.\n");
	}

	fh = accelerometer_freerunner_open_threshold("r");
	if ( fh == NULL ) {
		fprintf(stderr, "Failed to restore accelerometer threshold.\n");
		return;
	}
	rval = fscanf(fh, "%i", &new_threshold);
	if ( rval != 1 ) {
		fprintf(stderr, "Couldn't read new accelerometer threshold\n");
	}
	fclose(fh);

	/* Restore only if it hasn't been altered externally */
	if ( new_threshold != 0 ) {
		printf("Threshold changed - not restoring.\n");
		return;
	}

	/* Set it back to the old value */
	fh = accelerometer_freerunner_open_threshold("w");
	if ( fh == NULL ) {
		fprintf(stderr, "Failed to restore accelerometer threshold.\n");
		return;
	}
	fprintf(fh, "%i\n", accel->old_threshold);
	printf("Successfully restored accelerometer threshold.\n");
	fclose(fh);
}

AccelHandle *accelerometer_open()
{
	AccelHandle *accel;

	/* Initialise accelerometer data structure */
	accel = malloc(sizeof(AccelHandle));
	if ( accel == NULL ) return NULL;
	accel->x = 0;
	accel->y = 0;
	accel->z = 0;
	accel->lx = 0;
	accel->ly = 0;
	accel->lz = 0;
	accel->state = 0;
	accel->type = ACCEL_UNKNOWN;

	/* Determine accelerometer type */
	accel->fd = open("/dev/input/by-path/platform-hdaps-event-joystick",
							O_RDONLY, O_NONBLOCK);
	if ( accel->fd != -1 ) {
		accel->type = ACCEL_HDAPS;
		printf("ThinkPad HDAPS detected\n");
		return accel;
	}

	accel->fd = open("/dev/input/event3", O_RDONLY, 0);
	if ( accel->fd != -1 ) {

		accel->type = ACCEL_FREERUNNER;
		printf("Neo Freerunner detected\n");
		accelerometer_freerunner_try_threshold(accel);

		return accel;
	}

	/* Try other types here */

	fprintf(stderr, "Couldn't determine accelerometer type\n");
	return accel;
}

static void accelerometer_shutdown(AccelHandle *accel)
{
	if ( accel->type == ACCEL_FREERUNNER ) {
		accelerometer_freerunner_try_restore_threshold(accel);
	}
}

int accelerometer_moo_hdaps(AccelHandle *accel)
{
	struct input_event ev;
	size_t rval;

	rval = read(accel->fd, &ev, sizeof(ev));
	if ( rval != sizeof(ev) ) {
		fprintf(stderr, "Couldn't read accelerometer data");
		return 0;
	}
	if (ev.type == EV_ABS && ev.code == REL_Y) {
		if (accel->state == 0 && abs(ev.value)>100) {
			// Laptop tilted far enough
			accel->state=1;
			return 0;
		}

		if (accel->state == 1 && abs(ev.value)<70) {
			// Laptop tilted back, play sound
			accel->state=2;
			return 1;
		}

		if (accel->state == 2 && abs(ev.value)<20) {
			// Laptop almost at center, enable another round
			accel->state=0;
			return 0;
		}
	}

	return 0;

	/*
 	fprintf(stderr, "Event: time %ld.%06ld, type %s, code %d, value %d\n",
		       ev.time.tv_sec, ev.time.tv_usec,
		       ev.type == EV_REL ? "REL" :
                       ev.type == EV_ABS ? "ABS" : "Other" ,
		       ev.code, ev.value);
	*/
}

int accelerometer_moo_freerunner(AccelHandle *accel)
{
	struct input_event ev;
	size_t rval;
	fd_set fds;
	struct timeval t;

	FD_ZERO(&fds);
	FD_SET(accel->fd, &fds);
	t.tv_sec = 0;
	t.tv_usec = 0;
	select(1+accel->fd, &fds, NULL, NULL, &t);

	if ( FD_ISSET(accel->fd, &fds) ) {

		rval = read(accel->fd, &ev, sizeof(ev));
		if ( rval != sizeof(ev) ) {
			fprintf(stderr, "Couldn't read accelerometer data");
			return 0;
		}

	} else {
		return 0;	/* No data */
	}

	/* Nasty, but the event type has changed.
	 * For now, we must support both types. */
	if ( (ev.type == EV_REL) || (ev.type == EV_ABS) ) {
		if ( ev.code == REL_X ) {
			accel->lx = ev.value;
		}
		if ( ev.code == REL_Y ) {
			accel->ly = ev.value;
		}
		if ( ev.code == REL_Z ) {
			accel->lz = ev.value;
		}
	}

	if ( ev.type == EV_SYN ) {
		if ( ev.code == SYN_REPORT ) {
			accel->x = accel->lx;
			accel->y = accel->ly;
			accel->z = accel->lz;
		}
	}

	if ( (accel->y < -500) && (accel->state > -1000) ) {
		accel->state = -1000;
		return 1;
	}

	if ( (accel->y > 500) && (accel->state < 1000) ) {
		accel->state = 1000;
		return 1;
	}

	return 0;
}

int accelerometer_moo(AccelHandle *accel)
{
	switch ( accel->type ) {
		case ACCEL_UNKNOWN : {
			return 0;
		}
		case ACCEL_FREERUNNER : {
			return accelerometer_moo_freerunner(accel);
		}
		case ACCEL_HDAPS : {
			return accelerometer_moo_hdaps(accel);
		}
		/* Add other types here. */
	}

	return 0;
}

/* The accelerometer work thread */
static void *accel_work(void *data)
{
	AccelHandle *accel;
	int *finished = data;

	accel = accelerometer_open();
	audio_setup();

	while ( !(*finished) ) {

		if (accelerometer_moo(accel))
			audio_trigger_moo();

		usleep(25000);

	}

	accelerometer_shutdown(accel);
	audio_shutdown();

	return NULL;
}

GThread *accelerometer_start(int *finished)
{
	return g_thread_create(accel_work, finished, TRUE, NULL);
}