#include "pico/stdlib.h"
#include "hardware/spi.h"
#include <cstdint>
#include <stdint.h>

#include "max31856.h"

void max31856_init(max31856_t *max)
{
   // init GPIO for CS
   gpio_init(max->pin_cs);
   gpio_set_dir(max->pin_cs, GPIO_OUT);
   gpio_put(max->pin_cs, 1);

   // init SPI
   spi_init(SPI_MAX31856, SPI_MAX31856_BOUD);
   spi_set_format(SPI_MAX31856, SPI_MAX31856_BLOCK_SIZE, SPI_MAX31856_SPO, SPI_MAX31856_SPH, SPI_MAX31856_BIT_ORDER);

   max->initilzed = true;
}

void max31856_deinit(max31856_t *max)
{
   max->initilzed = false;
   spi_deinit(SPI_MAX31856);
   gpio_deinit(max->pin_cs);
}

int max31856_write8(max31856_t *max, uint8_t addr, uint8_t value)
{
   if (!(max->initilzed))
   {
      return -1;
   }
   uint8_t buff[2] = {addr | 0x80, value};
   gpio_put(max->pin_cs, 0);
   spi_write_blocking(SPI_MAX31856, &buff[0], 2);
   gpio_put(max->pin_cs, 1);

   return 0;
}

uint8_t max31856_read8(max31856_t *max, uint8_t addr)
{
   if (!(max->initilzed))
   {
      return -1;
   }
   uint8_t buff_tx = addr & 0x7F;
   uint8_t buff_rx[] = {0, 0};
   gpio_put(max->pin_cs, 0);
   spi_read_blocking(SPI_MAX31856, buff_tx, &buff_rx[0], 2);
   gpio_put(max->pin_cs, 1);

   return buff_rx[1];
}

uint16_t max31856_read16(max31856_t *max, uint8_t addr)
{
   if (!(max->initilzed))
   {
      return -1;
   }
   uint8_t buff_tx = addr & 0x7F;
   uint8_t buff_rx[] = {0, 0, 0};
   gpio_put(max->pin_cs, 0);
   spi_read_blocking(SPI_MAX31856, buff_tx, &buff_rx[0], 3);
   gpio_put(max->pin_cs, 1);

   return buff_rx[1]<<8 | buff_rx[2];
}

uint32_t max31856_read24(max31856_t *max, uint8_t addr)
{
   if (!(max->initilzed))
   {
      return -1;
   }
   uint8_t buff_tx = addr & 0x7F;
   uint8_t buff_rx[] = {0, 0, 0, 0};
   gpio_put(max->pin_cs, 0);
   spi_read_blocking(SPI_MAX31856, buff_tx, &buff_rx[0], 4);
   gpio_put(max->pin_cs, 1);

   return 0 | buff_rx[1]<<16 | buff_rx[2]<<8 | buff_rx[3];
}

max31856_temp_t max31856_convert_cj_temp_c(uint16_t row) {
   bool negarive = ((row & 0x8000) == 0) ? false : true;
   if (negarive) {
      row = (~row) + 1;
   }

   max31856_temp_t temp = {
      (int16_t)(row >> 8),
      (uint8_t)(((row & 0xFF)*100)/256)
   };

   if (negarive) {
      temp.i = -temp.i;
   }

   return temp;
}

max31856_temp_t max31856_convert_tc_temp_c(uint32_t row) {
   bool negarive = ((row & 0x800000) == 0) ? false : true;
   if (negarive) {
      row = (row^0xFFFFFF) + 1;
   }
   row &= 0xFFFFFF;

   max31856_temp_t temp = {
      (int16_t)(row >> 12),
      (uint8_t)(((row & 0xFFF)*100)/0x1000)
   };

   if (negarive) {
      temp.i = -temp.i;
   }

   return temp;
}

max31856_temp_t max31856_get_cj_temp_c(max31856_t *max) {
   return max31856_convert_cj_temp_c(max31856_read16(max, MAX31856_REG_CJTH));
}

max31856_temp_t max31856_get_tc_temp_c(max31856_t *max) {
   return max31856_convert_tc_temp_c(max31856_read24(max, MAX31856_REG_LTCBH));
}