/* * Copyright (c) 2023 Carl Klemm <carl@uvos.xyz>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *  * Neither the name of %ORGANIZATION% nor the names of its contributors may be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#define _POSIX_C_SOURCE 199309L

#include <stdint.h>
#include "eismultiplexer.h"
#include "usbshm.h"
#include <stdlib.h>
#include <time.h>
#include <stdio.h>
#include <sys/time.h>

#ifdef WIND32
#include <synchapi.h>
#endif

typedef enum
{
	COMMAND_LED_OFF = 0,
	COMMAND_LED_ON,
	COMMAND_SET_OUTPUTS,
	COMMAND_GET_OUTPUTS,
	COMMAND_EEPROM_READ,
	COMMAND_EEPROM_WRITE,
	COMMAND_GET_GITREV,
	COMMAND_GET_CHANNEL_COUNT,
	COMMAND_GET_PROTO_VERSION,
	COMMAND_SET_TRIG,
	COMMAND_GET_TRIG,
	COMMAND_GET_TRIG_COUNT
} command_t;

static void msleep(uint64_t milliseconds)
{
#ifdef WIN32
	Sleep(milliseconds);
#else
	struct timespec ts;
	ts.tv_sec = milliseconds / 1000;
	ts.tv_nsec = (milliseconds % 1000) * 1000000;
	nanosleep(&ts, NULL);
#endif
}

uint16_t* eismultiplexer_list_available_devices(size_t* count)
{
	struct usbshm shm = {};
	*count = 0;
	unsigned char** serials;
	int ret = usbshm_find(&shm, 0xfe17, 0x07dc, &serials, count);
	usbshm_close(&shm);
	if(ret < 0 || *count == 0)
		return NULL;
	uint16_t* numeric_serials = malloc(sizeof(*numeric_serials)*(*count));
	for(size_t i = 0; i < *count; ++i) {
		numeric_serials[i] = atoi((char*)serials[i]);
	}
	return numeric_serials;
}

int eismultiplexer_connect(struct eismultiplexer* muliplexer, uint16_t serial)
{
	int ret;
	muliplexer->priv = malloc(sizeof(*muliplexer->priv));
	if(!muliplexer->priv)
		return -1;

	unsigned char serialStr[5];
	snprintf((char*)serialStr, sizeof(serialStr), "%04hu", serial);

	ret = usbshm_open(muliplexer->priv, 0xfe17, 0x07dc , serial == 0 ? NULL : serialStr);
	if(ret)
		return -3;
	return 0;
}

int eismultiplexer_connect_channel_exclusive(struct eismultiplexer* muliplexer, channel_t channel)
{
	uint16_t wValue;
	// we compile with fno-strict-aliasing
	uint8_t* wValChar = (uint8_t*)&wValue;
	wValChar[0] = channel;
	wValChar[1] = 0;
	return usbshm_write_control_transfer(muliplexer->priv, 2, NULL, 0, wValue, 0);
}

int eismultiplexer_connect_channel(struct eismultiplexer* muliplexer, channel_t channel)
{
	channel_t channels = eismultiplexer_get_connected(muliplexer);
	channels |= channel;
	return eismultiplexer_connect_channel_exclusive(muliplexer, channels);
}

int eismultiplexer_disconnect_channel(struct eismultiplexer* muliplexer, channel_t channel)
{
	channel_t channels = CHANNEL_NONE;
	if(channel != CHANNEL_NONE)
	{
		channels = eismultiplexer_get_connected(muliplexer);
		channels &= ~channel;
	}
	return eismultiplexer_connect_channel_exclusive(muliplexer, channels);
}

channel_t eismultiplexer_get_connected(struct eismultiplexer* muliplexer)
{
	uint8_t buffer[2] = {};
	usbshm_read_control_transfer(muliplexer->priv, 3, 0, 0, buffer, 1);
	return buffer[0];
}

int eismultiplexer_get_channel_count(struct eismultiplexer* muliplexer, uint16_t *count)
{
	uint8_t buffer[2] = {};
	int ret = usbshm_read_control_transfer(muliplexer->priv, 7, 0, 0, buffer, 1);
	*count = buffer[0];
	return ret;
}

int eismultiplexer_set_led(struct eismultiplexer* muliplexer, bool on)
{
	int ret;
	ret = usbshm_write_control_transfer(muliplexer->priv, on, NULL, 0, 0, 0);
	return ret;
}

int eismultiplexer_write_eeprom(struct eismultiplexer* muliplexer, uint16_t addr, uint16_t value)
{
	int ret;
	ret = usbshm_write_control_transfer(muliplexer->priv, 5, NULL, 0, value, addr);
	return ret;
}

uint16_t eismultiplexer_read_eeprom(struct eismultiplexer* muliplexer, uint16_t addr)
{
	uint8_t buffer[2] = {};
	usbshm_read_control_transfer(muliplexer->priv, 4, 0, addr, buffer, 2);
	return *((uint16_t*)buffer);
}

int eismultiplexer_set_trigger_state(struct eismultiplexer* muliplexer, uint16_t index, trigger_state_t state)
{
	int ret;
	ret = usbshm_write_control_transfer(muliplexer->priv, COMMAND_SET_TRIG, NULL, 0, state, index);
	return ret;
}

int eismultiplexer_get_trigger_state(struct eismultiplexer* muliplexer, uint16_t index, trigger_state_t* state, bool* level)
{
	uint8_t buffer[2] = {};
	int ret = usbshm_read_control_transfer(muliplexer->priv, COMMAND_GET_TRIG, 0, index, buffer, 2);
	if(ret == 2) {
		if(state)
			*state = buffer[1];
		if(level)
			*level = buffer[0];
	}
	return ret;
}

int eismultiplexer_wait_trigger(struct eismultiplexer* muliplexer, uint16_t index, trigger_wait_t wait, uint64_t timeout)
{
	bool level;
	bool prevlevel;
	int ret = eismultiplexer_get_trigger_state(muliplexer, index, NULL, &prevlevel);
	if(ret != 2)
		return ret;

	struct timeval start;
	struct timeval current;
	gettimeofday(&start, NULL);
	gettimeofday(&current, NULL);
	while((current.tv_sec - start.tv_sec)*1000 + (current.tv_usec - start.tv_usec)/1000 < timeout) {
		int ret = eismultiplexer_get_trigger_state(muliplexer, index, NULL, &level);
		if(ret != 2)
			return ret;
		switch(wait) {
			case TRIGGER_WAIT_HIGH_LEVEL:
				if(level)
					return 0;
			break;
			case TRIGGER_WAIT_LOW_LEVEL:
				if(!level)
					return 0;
			break;
			case TRIGGER_WAIT_EDGE:
				if(prevlevel != level)
					return 0;
			break;
			case TRIGGER_WAIT_HIGH:
				if(!prevlevel && level)
					return 0;
			break;
			case TRIGGER_WAIT_LOW:
				if(prevlevel && !level)
					return 0;
			break;
		}
		msleep(100);
		gettimeofday(&current, NULL);
	}
	return 1;
}

int eismultiplexer_get_trigger_count(struct eismultiplexer* muliplexer)
{
	uint8_t buffer[1] = {};
	int ret = usbshm_read_control_transfer(muliplexer->priv, COMMAND_GET_TRIG, 0, 0, buffer, 1);
	if(ret >= 0)
		return buffer[0];
	else
		return 0;
}

void eismultiplexer_disconnect(struct eismultiplexer* muliplexer)
{
	usbshm_close(muliplexer->priv);
	free(muliplexer->priv);
	muliplexer->priv = NULL;
}