#include "aio.h"
#include "log.h"

#include <math.h>
#include <stdio.h>
#include <string.h>

static constexpr uint16_t usb_timeout = 250;
static constexpr uint8_t buf_size = 32; // needs 32 bc of overflow issue on these aios?
static constexpr uint8_t max_curve_points = 7;

static uint8_t req[buf_size], resp[buf_size];

static const struct curve_point_t fan_curve[] = {
	{ .temp = 37, .duty = 15 },
	{ .temp = 40, .duty = 40 },
	{ .temp = 46, .duty = 60 },
	{ .temp = 50, .duty = 100 }
};

static void aio_usb_claim(libusb_device_handle *dev) {
	int ret = libusb_claim_interface(dev, 0);
	if (ret != 0) {
		applog(LOG_ERR, "failed to claim AIO device: %s", libusb_error_name(ret));
		return;
	}
	ret = libusb_control_transfer(dev, (LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE), 0x02, 0x02, 0, nullptr, 0, usb_timeout);
	if (ret < 0)
		applog(LOG_ERR, "AIO clear-to-send failed: %s", libusb_error_name(ret));
}

static void aio_usb_release(libusb_device_handle *dev) {
	libusb_release_interface(dev, 0);
}

static int aio_post(libusb_device_handle *dev, const int req_len, const int resp_len) {
	// applog(LOG_DBG, "writing to aio reg 0x%02x", req[0]);
	int ret = 0;
	ret += libusb_bulk_transfer(dev, 0x01, req, req_len, nullptr, usb_timeout);
	ret += libusb_bulk_transfer(dev, 0x81, resp, resp_len, nullptr, usb_timeout);
	return ret;
}

static float aio_get_water_temp(libusb_device_handle *dev) {
	req[0] = 0xa9;
	aio_post(dev, 1, 6);
	return (float)resp[3] + (float)resp[4] / 10.0f;
}

static uint16_t aio_get_pump_speed(libusb_device_handle *dev) {
	req[0] = 0x31;
	if (aio_post(dev, 1, 5) != 0)
		return UINT16_MAX;
	return (uint16_t)(resp[3] << 8 | resp[4]);
}

static enum aio_pump_mode_t aio_get_pump_mode(libusb_device_handle *dev) {
	req[0] = 0x33;
	if (aio_post(dev, 1, 4) != 0)
		return AIO_PUMP_MODE_UNKNOWN;
	return (enum aio_pump_mode_t)resp[3];
}

static void aio_get_fan_speed(libusb_device_handle *dev, uint16_t *speeds) {
	for (uint8_t i = 0; i < 2; i++) {
		req[0] = 0x41;
		req[1] = i;
		if (aio_post(dev, 2, 6) != 0)
			speeds[i] = UINT16_MAX;
		speeds[i] = (uint16_t)(resp[4] << 8 | resp[5]);
	}
}

static void aio_set_fan_duty(libusb_device_handle *dev, const uint8_t *duty) {
	if (duty == nullptr)
		return;
	static uint8_t last_duty = 255;
	if (duty[0] == last_duty)
		return;
	req[0] = 0x42;
	for (uint8_t i = 0; i < 2; i++) {
		req[1] = i;
		req[2] = MIN(MAX(duty[i], 0), 100);
		if (aio_post(dev, sizeof(req), buf_size) == 0)
			last_duty = req[2];
	}
}

static char *aio_get_firmware_version(libusb_device_handle *dev, char *buf) {
	req[0] = 0xaa;
	aio_post(dev, 1, buf_size);
	sprintf(buf, "%d.%d.%d.%d", resp[3], resp[4], resp[5], resp[6]);
	return buf;
}

static void aio_set_pump_mode(libusb_device_handle *dev, const enum aio_pump_mode_t mode) {
	static enum aio_pump_mode_t last_mode = AIO_PUMP_MODE_UNKNOWN;
	if (mode == last_mode)
		return;
	applog(LOG_DBG, "setting pump to %u", mode);
	req[0] = 0x32;
	req[1] = (uint8_t)mode;
	if (aio_post(dev, 2, 6) == 0)
		last_mode = mode;
}

static void aio_set_color(libusb_device_handle *dev, const enum aio_color_mode_t mode, const uint8_t speed, const struct rgb_t *colors, const uint8_t color_count) {
	if (colors == nullptr) // NOLINT no its not
		return;

	constexpr uint8_t modes[] = {0x52, 0x55, 0x55, 0x58};


	req[0] = 0x56;
	req[1] = color_count;

	// sort out and send color table
	memcpy(&req[2], colors, color_count * 3);
	if (color_count < 2 || mode == AIO_COLOR_FIXED) {
		memcpy(&req[5], colors, 3); // copy the same color to the 2nd pos in the table
		req[1] = 2;
	}
	aio_post(dev, 2 + req[1] * 3, buf_size);

	// send speed, skip if fixed color
	if (mode != AIO_COLOR_FIXED) {
		constexpr uint8_t speed_shift[] = {0x46, 0x28, 0x0F};
		constexpr uint8_t speed_pulse[] = {0x50, 0x37, 0x1E};
		req[0] = 0x53;
		req[1] = mode == AIO_COLOR_SHIFT ? speed_shift[speed] : speed_pulse[speed];
		aio_post(dev,2,  buf_size);
	}

	// actually set the aio to desired mode
	req[0] = modes[mode];
	req[1] = 0x01;
	aio_post(dev, 2, buf_size);
}

static void aio_set_fan_curve(libusb_device_handle *dev, const struct curve_point_t *curve, const uint8_t count) {
	if (curve == nullptr)
		return;

	if (count < 1 || count > max_curve_points) {
		applog(LOG_ERR, "aio: curve must have 1-%d points", max_curve_points);
		return;
	}

	struct curve_point_t padded[max_curve_points];
	for (int i = 0; i < max_curve_points; i++)
		padded[i] = (i < count) ? curve[i] : curve[count - 1];

	// uint8_t req[16], resp[32];
	req[0] = 0x40;

	// setup request
	for (int i = 0; i < max_curve_points; i++)
		req[2 + i] = padded[i].temp;
	for (int i = 0; i < max_curve_points; i++)
		req[9 + i] = padded[i].duty;

	// set curve for both fans
	for (uint8_t i = 0; i < 2; i++) {
		req[1] = i;
		aio_post(dev, sizeof(req), sizeof(resp));
	}
	applog(LOG_INF, "set up AIO fan curve");
}

void aio_detect(struct aio_t *aio) {
	libusb_init(nullptr);
	aio->handle = libusb_open_device_with_vid_pid(nullptr, AIO_USB_VID, AIO_USB_PID);
	if (aio->handle == nullptr) {
		applog(LOG_ERR, "Can't open AIO USB device %x:%x", AIO_USB_VID, AIO_USB_PID);
		return;
	}

	/* detaches other software that might take the device? */
	if (libusb_kernel_driver_active(aio->handle, 0))
		libusb_detach_kernel_driver(aio->handle, 0);

	aio_usb_claim(aio->handle);
	applog(LOG_INF, "found Corsair AIO device at %04x:%04x, fw ver: %s", AIO_USB_VID, AIO_USB_PID, aio_get_firmware_version(aio->handle, (char[16]){0}));
	aio_set_fan_duty(aio->handle, nullptr); // so it doenst complain the func is unused
	aio_set_fan_curve(aio->handle, fan_curve, sizeof(fan_curve) / sizeof(fan_curve[0]));
	aio_set_pump_mode(aio->handle, AIO_PUMP_MODE_QUIET); // needed for init ig?
	aio_set_color(aio->handle, AIO_COLOR_FIXED, 0, nullptr, 0); // so it doenst complain the func is unused
	aio_usb_release(aio->handle);
}

void aio_update(struct aio_t *aio) {
	if (aio->handle == nullptr)
		return;

	aio_usb_claim(aio->handle);

	aio->water_temp = aio_get_water_temp(aio->handle);
	aio->pump_speed = aio_get_pump_speed(aio->handle);
	aio->pump_mode = aio_get_pump_mode(aio->handle);
	aio_get_fan_speed(aio->handle, aio->fan_speed);

	const uint16_t avg_rpm = (uint16_t)((aio->fan_speed[0] + aio->fan_speed[1]) / 2);
	switch (aio->pump_mode) {
		case AIO_PUMP_MODE_QUIET:
			if (avg_rpm >= 500)
				aio->pump_counter++;
			else
				aio->pump_counter = 0;

			if (aio->pump_counter >= 300) {
				aio->pump_counter = 0;
				aio_set_pump_mode(aio->handle, AIO_PUMP_MODE_BALANCED);
			}
		break;
		case AIO_PUMP_MODE_BALANCED:
			if (avg_rpm >= 700)
				aio->pump_counter++;
			else if (avg_rpm <= 400)
				aio->pump_counter--;
			else
				aio->pump_counter = 0;

			if (aio->pump_counter >= 300) {
				aio->pump_counter = 0;
				aio_set_pump_mode(aio->handle, AIO_PUMP_MODE_EXTREME);
			}
			if (aio->pump_counter <= -300) {
				aio->pump_counter = 0;
				aio_set_pump_mode(aio->handle, AIO_PUMP_MODE_QUIET);
			}
		break;
		case AIO_PUMP_MODE_EXTREME:
			if (avg_rpm <= 500)
				aio->pump_counter--;
			else
				aio->pump_counter = 0;

			if (aio->pump_counter <= -300) {
				aio->pump_counter = 0;
				aio_set_pump_mode(aio->handle, AIO_PUMP_MODE_BALANCED);
			}
		break;
		case AIO_PUMP_MODE_UNKNOWN:
		break;
	}

	aio_usb_release(aio->handle);
}

void aio_close(const struct aio_t *aio) {
	aio_set_pump_mode(aio->handle, AIO_PUMP_MODE_BALANCED);
	libusb_attach_kernel_driver(aio->handle, 0); // reattach so liquidctl still works
	libusb_close(aio->handle);
	libusb_exit(nullptr);
	applog(LOG_INF, "AIO device closed");
}