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

#include <unistd.h>

static const uint8_t buf_size = 32; // needs 32 bc of overflow issue on these aios?

static void aio_post(libusb_device_handle *dev, uint8_t *req, const int req_len, uint8_t *resp, const int resp_len) {
	libusb_bulk_transfer(dev, 0x01, req, req_len, NULL, 1000);
	libusb_bulk_transfer(dev, 0x81, resp, resp_len, NULL, 1000);
}

static float aio_get_water_temp(libusb_device_handle* aio) {
	uint8_t req = 0xa9;
	uint8_t resp[buf_size];
	aio_post(aio, &req, sizeof(req), resp, 6);
	return (float)resp[3] + (float)resp[4] / 10.0f;
}

static uint16_t aio_get_pump_speed(libusb_device_handle* aio) {
	uint8_t req = 0x31;
	uint8_t resp[buf_size];
	aio_post(aio, &req, sizeof(req), resp, 5);
	return resp[3] << 8 | resp[4];
}

static enum aio_pump_mode_t aio_get_pump_mode(libusb_device_handle* aio) {
	uint8_t req = 0x33;
	uint8_t resp[buf_size];
	aio_post(aio, &req, sizeof(req), resp, 4);
	return (enum aio_pump_mode_t)resp[3];
}

static void aio_get_fan_speed(libusb_device_handle* aio, uint16_t *speeds) {
	uint8_t req[2] = {0x41};
	uint8_t resp[buf_size];

	for (uint8_t i = 0; i < 2; i++) {
		req[1] = i;
		aio_post(aio, req, sizeof(req), resp, 6);
		speeds[i] = resp[4] << 8 | resp[5];
	}
}

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

	/* detach kernel driver if attached */
	if (libusb_kernel_driver_active(aio->handle, 0))
		libusb_detach_kernel_driver(aio->handle, 0);

	const int ret = libusb_claim_interface(aio->handle, 0);
	if (ret == 0)
		applog(LOG_INF, "found Corsair AIO device at %04x:%04x", CORSAIR_VID, AIO_PID);
	else
		applog(LOG_ERR, "failed to claim AIO device");
}

void aio_update(struct aio_t *aio) {
	if (aio->handle == NULL)
		return;
	aio->water_temp = aio_get_water_temp(aio->handle);
	aio->pump_speed = aio_get_pump_speed(aio->handle);
	aio->mode = aio_get_pump_mode(aio->handle);
	aio_get_fan_speed(aio->handle, aio->fan_speed);
}

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