/*
  Linux userspace test code, simple and mose code directy from the doco.
  compile like this: gcc linux_userspace.c ../bme280.c -I ../ -o bme280
  tested: Raspberry Pi.
  Use like: ./bme280 /dev/i2c-0
*/
#include "bme280.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/i2c-dev.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <fcntl.h>

int fd;

int8_t user_i2c_read(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
{
  write(fd, &reg_addr,1);
  read(fd, data, len);
  return 0;
}

void user_delay_ms(uint32_t period)
{
  usleep(period*1000);
}

int8_t user_i2c_write(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
{
  int8_t *buf;
  buf = malloc(len +1);
  buf[0] = reg_addr;
  memcpy(buf +1, data, len);
  write(fd, buf, len +1);
  free(buf);
  return 0;
}

void print_sensor_data(struct bme280_data *comp_data)
{
#ifdef BME280_FLOAT_ENABLE
  printf("temp %0.2f, p %0.2f, hum %0.2f\r\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
#else
  printf("temp %ld, p %ld, hum %ld\r\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
#endif
}

int8_t stream_sensor_data_forced_mode(struct bme280_dev *dev)
{
  int8_t rslt;
  uint8_t settings_sel;
  struct bme280_data comp_data;

  /* Recommended mode of operation: Indoor navigation */
  dev->settings.osr_h = BME280_OVERSAMPLING_1X;
  dev->settings.osr_p = BME280_OVERSAMPLING_16X;
  dev->settings.osr_t = BME280_OVERSAMPLING_2X;
  dev->settings.filter = BME280_FILTER_COEFF_16;

  settings_sel = BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL | BME280_OSR_HUM_SEL | BME280_FILTER_SEL;

  rslt = bme280_set_sensor_settings(settings_sel, dev);

  printf("Temperature, Pressure, Humidity\r\n");
  /* Continuously stream sensor data */
  while (1) {
    rslt = bme280_set_sensor_mode(BME280_FORCED_MODE, dev);
    /* Wait for the measurement to complete and print data @25Hz */
    dev->delay_ms(40);
    rslt = bme280_get_sensor_data(BME280_ALL, &comp_data, dev);
    print_sensor_data(&comp_data);
  }
  return rslt;
}

int main(int argc, char* argv[])
{
  struct bme280_dev dev;
  int8_t rslt = BME280_OK;

  if ((fd = open(argv[1], O_RDWR)) < 0) {
    printf("Failed to open the i2c bus %s", argv[1]);
    exit(1);
  }
  if (ioctl(fd, I2C_SLAVE, 0x76) < 0) {
    printf("Failed to acquire bus access and/or talk to slave.\n");
    exit(1);
  }
  dev.dev_id = BME280_I2C_ADDR_PRIM;
  dev.intf = BME280_I2C_INTF;
  dev.read = user_i2c_read;
  dev.write = user_i2c_write;
  dev.delay_ms = user_delay_ms;

  rslt = bme280_init(&dev);
  stream_sensor_data_forced_mode(&dev);
}