#ifndef MPU6000_H
#define MPU6000_H

#include <spi/spi.h>
#include <gpio/gpio.h>
#include <os/time.h>

class MPU6000 {
	private:
		Pin cs;
		SPI_t& spi;
		uint8_t raw_data[14];
		
		void read_register(uint8_t reg, uint8_t len, uint8_t *data) {
			cs.off();
			spi.transfer_byte(reg | (1 << 7)); // Read bit
			while(len--) {
				*data++ = spi.transfer_byte();
			}
			cs.on();
		}
		
		void write_register(uint8_t reg, uint8_t data) {
			cs.off();
			spi.transfer_byte(reg);
			spi.transfer_byte(data);
			cs.on();
		}
		
	public:
		MPU6000(Pin cs_pin, SPI_t& spi_bus) : cs(cs_pin), spi(spi_bus) {}
		float gyro [3] = {0,0,0}; //X Y Z
		float accel [3] = {0,0,0}; //X Y Z
		
		void init() {
			spi.reg.CR1 = (1 << 9) | (1 << 8) | (1 << 6) | (2 << 3) | (1 << 2) | (1 << 1) | (1 << 0); // SSM On | SSI 1 | SPE On | BR /8 | CPOL CK 1 Idle | CPHA Second clock data capture
			spi.reg.CR2 = (1 << 12) | ( 7 << 8); // FRXTH RXNE if FIFO >= 8bit | DS 8-bit
			write_register(0x6B, (1 << 7)); // Device Reset
			Time::sleep(150);
			uint8_t who_am_i = 0x00;
			while (who_am_i != 0x68) {
				read_register(0x75, 1, &who_am_i); //WHO_AM_I register
			}
			write_register(0x19, 4); // SAMPLE DIV 4
			Time::sleep(1);
			write_register(0x1A, (3 << 0)); // CONFIG - DLPF_CFG 42hz
			Time::sleep(1);
			write_register(0x1B, (3 << 3)); // GYRO_CFG, 2000 deg/s
			Time::sleep(1);
			write_register(0x1C, (3 << 3)); // ACCEL_CFG, +-16g
			Time::sleep(1);
			write_register(0x6A, (1 << 4)); // USER_CTRL - I2C Off
			Time::sleep(1);
			write_register(0x6B, (3 << 0)); // PWR_MGMT_1 - CLKSEL PLL_Z
			Time::sleep(1);
			write_register(0x6C, 0); // PWR_MGMT_2
			Time::sleep(150);
		}
		
		
		void update() {
			int16_t temp;
			spi.reg.CR1 = (1 << 9) | (1 << 8) | (1 << 6) | (2 << 3) | (1 << 2) | (1 << 1) | (1 << 0); // SSM On | SSI 1 | SPE On | BR /8 | CPOL CK 1 Idle | CPHA Second clock data capture
			spi.reg.CR2 = (1 << 12) | ( 7 << 8); // FRXTH RXNE if FIFO >= 8bit | DS 8-bit
			
			read_register(0x3B, 14, raw_data); // Accel 0-5, Temp 6-7, Gyro 8-13
			
			temp = raw_data[0] << 8;
			temp |= raw_data[1];
			accel[0] = float(temp) * 2 / 32768.0f;
			temp = raw_data[2] << 8;
			temp |= raw_data[3];
			accel[1] = float(temp) * 2 / 32768.0f;
			temp = raw_data[4] << 8;
			temp |= raw_data[5];
			accel[2] = float(temp) * 2 / 32768.0f;
			
			temp = raw_data[8] << 8;
			temp |= raw_data[9];
			gyro[0] = float(temp) * 2000 / 32768.0f;
			temp = raw_data[10] << 8;
			temp |= raw_data[11];
			gyro[1] = float(temp) * 2000 / 32768.0f;
			temp = raw_data[12] << 8;
			temp |= raw_data[13];
			gyro[2] = float(temp) * 2000 / 32768.0f;
		}
};

#endif