#include <stm32f0xx.h>
#include "bme680-driver-fork/bme680.h"
#include <delay.h>
#include <lcd.h>
#include <stdlib.h>

unsigned int i = 0x12345678;
unsigned char c = 2;

#define OUTPUT(pin)  (0x01U << (pin * 2))
#define PULLUP(pin)	(0x1U << (pin* 2))
#define ALTFUNC(pin) ((0x2) << (pin * 2))
#define PINMASK(pin) ((0x3) << (pin * 2))
#define SETAF(PORT,PIN,AF)  PORT->AFR[(PIN < 8 ? 0 : 1)] |= AF << ((PIN < 8 ? PIN : (PIN - 8)) * 4)

static struct bme680_dev gas_sensor;
static volatile uint8_t backlight_counter;

static uint8_t spi_transfer(uint8_t out_data)
{
	while(SPI1->SR & SPI_SR_BSY);
	SPI1->DR.DR8.DR8_1 = out_data;
	__DSB();
	while((SPI1->SR & SPI_SR_BSY) || !(SPI1->SR & SPI_SR_TXE));
	return (uint8_t)(SPI1->DR.DR8.DR8_1 & 0xFF);
}

static int8_t write_spi(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
{
	(void)dev_id;
	int i;

	GPIOA->ODR &= ~(1U<<4);

	spi_transfer(reg_addr);

	for (i = 0; i < len; i++)
		spi_transfer(reg_data[i]);

	GPIOA->ODR |= (1U<<4);

	return 0;
}


static int8_t read_spi(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
{
	(void)dev_id;
	int i;

	GPIOA->ODR &= ~(1U<<4);

	spi_transfer(reg_addr);

	for (i = 0; i < len; i++)
		reg_data[i] = spi_transfer(0x00);

	GPIOA->ODR |= (1U<<4);

	return 0;
}

uint32_t gas_res;
int16_t temp = 2000;
struct bme680_field_data data;

int main(void) {
	char display_data[20];

	RCC->AHBENR |= RCC_AHBENR_GPIOFEN | RCC_AHBENR_GPIOAEN | RCC_AHBENR_GPIOBEN;
	RCC->APB2ENR |= RCC_APB2ENR_SPI1EN;

	GPIOA->MODER |= OUTPUT(4) | ALTFUNC(5) | ALTFUNC(7) | ALTFUNC(6) | OUTPUT(0) | OUTPUT(1) | OUTPUT(2) | OUTPUT(3) | OUTPUT(9) | OUTPUT(10);
	SETAF(GPIOA, 5, 0);
	SETAF(GPIOA, 6, 0);
	SETAF(GPIOA, 7, 0);
	GPIOF->MODER |= OUTPUT(0);
	GPIOF->PUPDR |= PULLUP(1);
	GPIOF->ODR |= (1<<0);

	/* Configure Systick for 1ms interval */
	SysTick_Config(8000/*00*/);


	lcd_init();

	lcd_setcursor(0,4);
	lcd_string("Initializing...");

	GPIOB->MODER |= OUTPUT(1);
	GPIOB->ODR &= ~(1<<1);


	GPIOA->ODR |= (1<<4);
	SPI1->CR1 = SPI_CR1_BR_2 | SPI_CR1_MSTR | SPI_CR1_SSM | SPI_CR1_SSI;
	SPI1->CR1 |= SPI_CR1_SPE;

	/* You may assign a chip select identifier to be handled later */
	gas_sensor.dev_id = 0;
	gas_sensor.intf = BME680_SPI_INTF;
	gas_sensor.read = read_spi;
	gas_sensor.write = write_spi;
	gas_sensor.delay_ms = delay_ms;
	/* amb_temp can be set to 25 prior to configuring the gas sensor
	* or by performing a few temperature readings without operating the gas sensor.
	*/
	gas_sensor.amb_temp = 12;

	int8_t rslt = BME680_OK;
	rslt = bme680_init(&gas_sensor);

	uint8_t set_required_settings;

	/* Set the temperature, pressure and humidity settings */
	gas_sensor.tph_sett.os_hum = BME680_OS_8X;
	gas_sensor.tph_sett.os_pres = BME680_OS_8X;
	gas_sensor.tph_sett.os_temp = BME680_OS_8X;
	gas_sensor.tph_sett.filter = BME680_FILTER_SIZE_7;

	/* Set the remaining gas sensor settings and link the heating profile */
	gas_sensor.gas_sett.run_gas = BME680_DISABLE_GAS_MEAS;
	/* Create a ramp heat waveform in 3 steps */
	gas_sensor.gas_sett.heatr_temp = 320; /* degree Celsius */
	gas_sensor.gas_sett.heatr_dur = 150; /* milliseconds */

	/* Select the power mode */
	/* Must be set before writing the sensor configuration */
	gas_sensor.power_mode = BME680_FORCED_MODE;

	/* Set the required sensor settings needed */
	set_required_settings = BME680_OST_SEL | BME680_OSP_SEL | BME680_OSH_SEL | BME680_FILTER_SEL | BME680_GAS_SENSOR_SEL;

	/* Set the desired sensor configuration */
	rslt = bme680_set_sensor_settings(set_required_settings,&gas_sensor);

	/* Set the power mode */
	rslt = bme680_set_sensor_mode(&gas_sensor);


	uint16_t meas_period;
	uint8_t meas_gas = 0;

	do {
		bme680_get_profile_dur(&meas_period, &gas_sensor);
		delay_ms(meas_period); /* Delay till the measurement is ready */

		if (meas_gas)
			gas_sensor.gas_sett.run_gas = BME680_ENABLE_GAS_MEAS;
		else
			gas_sensor.gas_sett.run_gas = BME680_DISABLE_GAS_MEAS;


		rslt = bme680_get_sensor_data(&data, &gas_sensor);
		temp = data.temperature - 300;
		gas_sensor.amb_temp = (int8_t)(data.temperature / 100)-3;
		/* Avoid using measurements from an unstable heating setup */
		if(data.status & BME680_GASM_VALID_MSK)
			gas_res = data.gas_resistance;

		lcd_home();
		display_data[0] = 0;
		itoa((int)data.temperature, display_data, 10);
		display_data[4] = display_data[3];
		display_data[3] = display_data[2];
		display_data[2] = '.';
		display_data[5] = 0x0;
		lcd_string(display_data);

	delay_ms(1000);

		if (gas_sensor.power_mode == BME680_FORCED_MODE) {
			bme680_set_sensor_settings(set_required_settings,&gas_sensor);
			rslt = bme680_set_sensor_mode(&gas_sensor);
		}
	} while(1);

}

void HardFault_Handler(void)
{
	while(1);
}

void SysTick_Handler(void) {
	static int internal_tick = 0;
	/* Blink bad air LED */
	tick++;
	internal_tick++;

	if (!(GPIOF->IDR & (1U<<1))) {
		backlight_counter = 30;
		GPIOB->ODR |= (1U<<1);
	}

	if (internal_tick > 200) {
		internal_tick = 0;
		if (backlight_counter > 0) {
			backlight_counter--;
		} else if (backlight_counter == 0) {
			GPIOB->ODR &= ~(1U<<1);
		}
		GPIOF->ODR ^= (1<<0);
	}
}