/**************************************************************************\
* Pinoccio Library                                                         *
* https://github.com/Pinoccio/library-pinoccio                             *
* Copyright (c) 2012-2014, Pinoccio Inc. All rights reserved.              *
* Derived from Jim Lindblom @ SparkFun, licensed (CC BY-SA 3.0)            *
* ------------------------------------------------------------------------ *
*  This program is free software; you can redistribute it and/or modify it *
*  under the terms of the BSD License as described in license.txt.         *
\**************************************************************************/
#include "halFuelGauge.h"
#include <Wire.h>
#include <Arduino.h>

int HAL_FuelGaugeVoltage() {
  unsigned int vcell;

  vcell = HAL_FuelGaugei2cRead16(0x02);
  vcell = vcell >> 4;  // last 4 bits of vcell are nothing
  return (vcell / 805.0f * 100);
}

int HAL_FuelGaugePercent() {
  unsigned int soc;
  float percent;

  soc = HAL_FuelGaugei2cRead16(0x04);  // Read SOC register of MAX17048G
  percent = (byte) (soc >> 8);  // High byte of SOC is percentage
  percent += ((float)((byte)soc))/256;  // Low byte is 1/256%

  return round(percent);
}

void HAL_FuelGaugeConfig(byte percent) {
  if ((percent >= 32)||(percent == 0)) { // Anything 32 or greater will set to 32%
    HAL_FuelGaugei2cWrite16(0x9700, 0x0C);
  } else {
    byte percentBits = 32 - percent;
    HAL_FuelGaugei2cWrite16((0x9700 | percentBits), 0x0C);
  }

  // VALERT min and max voltage setting of 3.1V and 4.3V respectively (20mV per LSb)
  HAL_FuelGaugei2cWrite16(0x9BD7, 0x14);
}

void HAL_FuelGaugeQuickStart() {
  HAL_FuelGaugei2cWrite16(0x4000, 0x06);  // Write a 0x4000 to the MODE register
}

byte HAL_FuelGaugeGetAlertReason() {
  return HAL_FuelGaugei2cRead16(0x1A >> 8);
}

void HAL_FuelGaugeClearAlert() {
  //TODO
}

unsigned int HAL_FuelGaugei2cRead16(unsigned char address) {
  int data = 0;

  Wire.beginTransmission(MAX17048G_ADDRESS);
  Wire.write(address);
  Wire.endTransmission();

  Wire.requestFrom(MAX17048G_ADDRESS, 2);
  while (Wire.available() < 2)
    ;
  data = ((int) Wire.read()) << 8;
  data |= Wire.read();

  return data;
}

void HAL_FuelGaugei2cWrite16(unsigned int data, unsigned char address) {
  Wire.beginTransmission(MAX17048G_ADDRESS);
  Wire.write(address);
  Wire.write((byte)((data >> 8) & 0x00FF));
  Wire.write((byte)(data & 0x00FF));
  Wire.endTransmission();
}