#include <linux/i2c-dev.h>
#include <i2c/smbus.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "icx3.h"

/* Check an I2C device file for an ICX3 controller, returns the product id, or ICX3_PRODUCT_NONE on bad read. */
enum icx3_product_id check_for_icx3(char *i2c_dev_path)
{
	char data[I2C_SMBUS_BLOCK_MAX] = {};
	int fd, read_result;
	struct icx3_info *temp_info;
	
	fd = open_i2c_dev(i2c_dev_path);
	if (fd == -1)
		return ICX3_PRODUCT_NONE;
	
	read_result = i2c_smbus_read_i2c_block_data(fd, ICX3_REG_READINFORMATION, ICX3_READINFORMATION_SIZE, data);
	close(fd);
	if (read_result == ICX3_READINFORMATION_SIZE) {
		temp_info = (struct icx3_info*)&data;
		if (temp_info->slave_address == ICX3_I2C_ADDR)
			return temp_info->product_id;
	}

	return ICX3_PRODUCT_NONE;
}

void print_icx3_fans(char *i2c_dev_path)
{
	char data[I2C_SMBUS_BLOCK_MAX] = {};
	int fd, read_result;
	
	struct icx3_fan_control *fan_status; 
	
	/* First thing is to check for the product ID to figure out how many fans we have */
	char fans_avail[ICX3_MAX_FANS] = {0};
	get_available_fans(i2c_dev_path, fans_avail);
	
	fd = open_i2c_dev(i2c_dev_path);
	if (fd == -1)
		return;
	
	for (int i=0; i < ICX3_MAX_FANS; i++) {
		if (!fans_avail[i])
			continue;
		
		read_result = i2c_smbus_read_i2c_block_data(fd, ICX3_REG_FANCONTROL + i, ICX3_FANCONTROL_SIZE, data);
		if (read_result != ICX3_FANCONTROL_SIZE) {
			close(fd);
			return;
		}
		fan_status = (struct icx3_fan_control*) &data;
		printf("%s: %d RPM (%d/%d%%, %s)\n",
			icx3_fan_names[i],
			fan_status->rpm_status,
			fan_status->duty_status,
			fan_status->duty,
			icx3_fan_mode_names[fan_status->fanmode]
			);
	}
	
	close(fd);
}

void print_icx3_temps(char *i2c_dev_path)
{
	char data[I2C_SMBUS_BLOCK_MAX] = {};
	int fd, read_result;
	struct icx3_temp_sensors *temp_sensors;
	
	fd = open_i2c_dev(i2c_dev_path);
	if (fd == -1)
		return;
	
	read_result = i2c_smbus_read_i2c_block_data(fd, ICX3_REG_TEMPSENSOR, ICX3_TEMPSENSOR_SIZE, data);
	if (read_result != ICX3_TEMPSENSOR_SIZE) {
		close(fd);
		return;
	}
	temp_sensors = (struct icx3_temp_sensors*) &data;
	
	float cur_temp;
	short cur_data;
	
	for (int i=0; i<ICX3_NUM_TEMP_SENSORS; i++) {
		/* endian swap */
		cur_data = (short)(temp_sensors->data[2*i+1] << 8) | (short)(temp_sensors->data[2*i]);
		/* temp is reported in tenths of deg C */
		cur_temp = (float)cur_data/10;
		printf("%s: %+.1f°C\n",
		icx3_temp_sensor_names[i],
		cur_temp);
	}
}

void get_available_fans(char *i2c_dev_path, char *fans_avail)
{
	int product_id = check_for_icx3(i2c_dev_path);
	
	/* From ICX3TotalFanCtrl.cs */
	switch(product_id) {
	case ICX3_PRODUCT_E221_E222_XC3:
	case ICX3_PRODUCT_E229_XC3:
	case ICX3_PRODUCT_E222_XC3_LPC54113:
	case ICX3_PRODUCT_E229_XC3_LPC54113:
	case ICX3_PRODUCT_E221_XC3_STM32L431:
	case ICX3_PRODUCT_E229_E237_XC3_STM32L431:
	/* XC3, default plus fan 3 */
		fans_avail[0] = 1;
		fans_avail[1] = 1;
		fans_avail[2] = 1;
		break;
	case ICX3_PRODUCT_E227_E228_FTW3:
	case ICX3_PRODUCT_E230_FTW3:
	case ICX3_PRODUCT_E227_E228_FTW3_LPC54113:
	case ICX3_PRODUCT_E230_FTW3_LPC54113:
	case ICX3_PRODUCT_E230_E238_FTW3_STM32L431:
	case ICX3_PRODUCT_E250_FTW3:
	/* FTW3, default plus fan 3 and external fan */
		fans_avail[0] = 1;
		fans_avail[1] = 1;
		fans_avail[2] = 1;
		fans_avail[3] = 1;
		break;
	case ICX3_PRODUCT_E223_KINGPIN_HYBRID:
	case ICX3_PRODUCT_E227_E228_FTW3_HYBRID:
	case ICX3_PRODUCT_E251_KINGPIN_HYBRID:
	case ICX3_PRODUCT_E227_E228_FTW3_HYBRID_LPC54113:
	case ICX3_PRODUCT_E250_FTW3_HYBRID:
	/* KINGPIN, default and external */
		fans_avail[0] = 1;
		fans_avail[1] = 1;
		fans_avail[3] = 1;
		break;
	case ICX3_PRODUCT_E227_E228_FTW3_HC:
	case ICX3_PRODUCT_E223_KINGPIN_HC:
	case ICX3_PRODUCT_E251_KINGPIN_HC:
	/* External fan only */
		fans_avail[3] = 1;
		break;
	default:
	/* default fans only */
		fans_avail[0] = 1;
		fans_avail[1] = 1;
		break;
	case ICX3_PRODUCT_E221_E222_XC3_HC:
	/* Not sure what this case is for */
		break;
	}
}

int open_i2c_dev(char *i2c_dev_path)
{
	int fd = open(i2c_dev_path, O_RDONLY);
	
	/* Error silently here because we should have already checked we can read the i2c in check_for_icx3() */
	if (fd == -1)
		return -1;
	
	if (ioctl(fd, I2C_SLAVE, ICX3_I2C_ADDR) < 0) {
		close(fd);
		return -1;
	}
	return fd;
}

void enable_write(int enable, char *i2c_dev_path)
{
	int fd = open_i2c_dev(i2c_dev_path);
	if (fd == -1)
		return;
	
	unsigned char *data;
	if (enable)
		data = icx3_write_enable;
	else
		data = icx3_write_disable;
	/* Enable or disable write */
    i2c_smbus_write_i2c_block_data(fd, ICX3_REG_ENABLEWRITE, ICX3_ENABLEWRITE_SIZE, data);
	
	/* Read back the result to verify */
	unsigned char read_result[ICX3_ENABLEWRITE_SIZE];
	int write_ok = 0;
	i2c_smbus_read_i2c_block_data(fd, ICX3_REG_ENABLEWRITE, ICX3_ENABLEWRITE_SIZE, read_result);
	if (enable)
		write_ok = (read_result[1] == 0xFC);
	else
		write_ok = (read_result[1] == 0xFE);
	
	if (!write_ok)
		printf("Unable to enable/disable write on %s\n", i2c_dev_path);

}

/* Sets a given fan on the GPU according to a string setting
'auto' resets the fan to default (fans 1-2 go to GPU control, 3-4 to +0 RPM offset from GPU control)
A number without a sign (e.g. 50) manually sets the fan to a given % duty cycle
A number with a sign (e.g. +500) sets the fan to run at an RPM offset from GPU control */
void set_fan(int fan, char *setting, char *i2c_dev_path)
{
	char fans_avail[ICX3_MAX_FANS] = {0};
	
	struct icx3_fan_control fan_control = {};
	struct icx3_fan_control fan_readback = {};
	char reg = ICX3_REG_FANCONTROL + fan;

	int write_result;
	
	/* Check to make sure we're setting a valid fan */
	get_available_fans(i2c_dev_path, fans_avail);
	if (fans_avail[fan] == 0) {
		printf("Fan %d does not exist on this card \n", fan);
		return;
	}

	int fp = open_i2c_dev(i2c_dev_path);
	if (fp == -1)
		return;
	
	fan_control.length = ICX3_FANCONTROL_SIZE - 1;
	if (strcmp(setting, "auto") == 0) {
		/* auto setting */
		fan_control.rpm_offset = 0;
		if (fan <= 1) 
			fan_control.fanmode = ICX3_FANMODE_GPU_CONTROL;
		else
			fan_control.fanmode = ICX3_FANMODE_GPU_RPM_OFFSET;
	} else if (setting[0] == '+' || setting[0] == '-') {
		/* RPM offset */
		fan_control.fanmode = ICX3_FANMODE_GPU_RPM_OFFSET;
		fan_control.rpm_offset = atoi(setting);
	} else {
		fan_control.fanmode = ICX3_FANMODE_RPM;
		fan_control.duty = atoi(setting);
	}

	enable_write(1, i2c_dev_path);
	
    i2c_smbus_write_i2c_block_data(fp, reg, ICX3_FANCONTROL_SIZE, (char *)&fan_control);

	/* Read back data and verify we set the fan properly */
    i2c_smbus_read_i2c_block_data(fp, reg, ICX3_FANCONTROL_SIZE, (char *)&fan_readback);
	if (fan_readback.fanmode    != fan_control.fanmode ||
		fan_readback.rpm_offset != fan_control.rpm_offset ||
		fan_readback.duty       != fan_control.duty)
		printf("Error setting fan %d on %s\n", fan, i2c_dev_path);
	close(fp);
}