/**
 * @file bme280.h
 * @author marisa (marisa@fwmari.net)
 * @brief BME280 helper
 * @version 0.1
 * @date 2024-05-06
 *
 * @copyright Copyright (c) 2024
 *
 */

#pragma once

#include <driver/i2c_master.h>
#include <stdint.h>

enum BME280Regs {
  // Start of first calibration data registers
  REG_CALIB00 = 0x88,

  // Temperature calibration data registers
  REG_T1 = 0x88,
  REG_T2 = 0x8A,
  REG_T3 = 0x8C,

  // Pressure calibration data registers
  REG_P1 = 0x8E,
  REG_P2 = 0x90,
  REG_P3 = 0x92,
  REG_P4 = 0x94,
  REG_P5 = 0x96,
  REG_P6 = 0x98,
  REG_P7 = 0x9A,
  REG_P8 = 0x9C,
  REG_P9 = 0x9E,

  // Humidity calibration data registers
  REG_H1 = 0xA1,
  REG_H2 = 0xE1,
  REG_H3 = 0xE3,
  REG_E4 = 0xE4,
  REG_E5 = 0xE5,
  REG_E6 = 0xE6,
  REG_H6 = 0xE7,

  // Start of second calibration data registers
  REG_CALIB26 = 0xE1,

  // System registers
  REG_CHIP_ID   = 0xD0,
  REG_RESET     = 0xE0,
  REG_CTRL_HUM  = 0xF2,
  REG_STATUS    = 0xF3,
  REG_CTRL_MEAS = 0xF4,
  REG_CONFIG    = 0xF5,

  // Start of raw data registers
  REG_RAWDATA = 0xF7,
  REG_P_MSB   = 0xF7,
  REG_P_LSB   = 0xF8,
  REG_P_XLSB  = 0xF9,
  REG_T_MSB   = 0xFA,
  REG_T_LSB   = 0xFB,
  REG_T_XLSB  = 0xFC,
  REG_H_MSB   = 0xFD,
  REG_H_LSB   = 0xFE,
};

struct BME280CalibParams {
  // Temperature trimming parameters
  uint16_t t1;
  int16_t  t2, t3;

  // Pressure trimming parameters
  uint16_t p1;
  int16_t  p2, p3, p4, p5, p6, p7, p8, p9;

  // Humidity trimming params
  uint8_t h1;
  int16_t h2;
  int8_t  h3, h4, h5, h6;
};

struct BME280Reading {
  double tempC, humidity, pressurehPa;
};

enum BME280Oversampling {
  OVSP_X1 = 1,
  OVSP_X2,
  OVSP_X4,
  OVSP_X8,
  OVSP_X16,
};

struct BME280 {
  struct BME280CalibParams calibParams;
  enum BME280Oversampling  oversampling;
  i2c_master_dev_handle_t  i2cHandle;
};

/**
 * @brief Initializes BME280 struct. Creates i2c handle, sets oversampling and calibParams
 *
 * @param bme
 */
void BME280Init(struct BME280 *bme, enum BME280Oversampling oversampling);

struct BME280Reading BME280Read(struct BME280 *bme);