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

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

static const uint16_t usb_timeout = 1000;
static const uint8_t buf_size = 32; // needs 32 bc of overflow issue on these aios?

// posts cmd to the aio, puts n bytes of response inside resp buffer
#define POST_AND_GET_RESP(cmd, n) uint8_t req = cmd; uint8_t resp[buf_size]; aio_post(dev, &req, 1, resp, n)

// posts 2 bytes of cmd to aio, puts n bytes of response inside resp buffer
#define POST_AND_GET_RESP2(cmd1, cmd2, n) uint8_t req[2] = {cmd1, cmd2}; uint8_t resp[buf_size]; aio_post(dev, req, 2, resp, n)

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, NULL, 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 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, usb_timeout);
	libusb_bulk_transfer(dev, 0x81, resp, resp_len, NULL, usb_timeout);
}

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

static uint16_t aio_get_pump_speed(libusb_device_handle* dev) {
	POST_AND_GET_RESP(0x31, 5);
	return resp[3] << 8 | resp[4];
}

static enum aio_pump_mode_t aio_get_pump_mode(libusb_device_handle* dev) {
	POST_AND_GET_RESP(0x33, 4);
	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++) {
		POST_AND_GET_RESP2(0x41, i, 6);
		speeds[i] = resp[4] << 8 | resp[5];
	}
}

static char* aio_get_firmware_version(libusb_device_handle* dev, char* buf) {
	POST_AND_GET_RESP(0xaa, 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) {
	POST_AND_GET_RESP2(0x32, mode, 6);
}

void aio_detect(struct aio_t *aio) {
	libusb_init(NULL);
	aio->handle = libusb_open_device_with_vid_pid(NULL, AIO_USB_VID, AIO_USB_PID);
	if (aio->handle == NULL) {
		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);
	aio_set_pump_mode(aio->handle, QUIET); // needed for init ig?
	aio_usb_release(aio->handle);
	applog(LOG_INF, "found Corsair AIO device at %04x:%04x, fw %s", AIO_USB_VID, AIO_USB_PID, aio_get_firmware_version(aio->handle, (char[16]){0}));
}

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

	if (aio->water_temp > 36.0f && aio->pump_mode != BALANCED)
		aio_set_pump_mode(aio->handle, BALANCED);

	if (aio->water_temp < 34.0f && aio->pump_mode != QUIET)
		aio_set_pump_mode(aio->handle, QUIET);

	aio_usb_release(aio->handle);
}

void aio_close(const struct aio_t *aio) {
	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");
}