'use strict';

const err_msg = 'AMG8833 is already opened. Please close old connection to use new one.';
const pig = require(`${apptool.gpio_lib}`);

let pi = -1;
let i2c_hand = -1;
exports.init = async (i2c_bus, i2c_addr, wael = null) => {
  if (wael !== null) {
    wael('beforeunload', async () => {
      await exports.stop();
    });
  }
  if (pi >= 0) { throw new Error(err_msg); return; }
  pi = await pig._rgpiod_start('', '');
  console.log('pi=' + pi);
  if (i2c_hand >= 0) { throw new Error(err_msg); return; }
  i2c_hand = await pig._i2c_open(pi, i2c_bus, i2c_addr, 0);
  console.log('i2c_hand=' + i2c_hand);
  await pig._i2c_write_byte_data(pi, i2c_hand, 0x00, 0x00); //Normal mode
  await pig._i2c_write_byte_data(pi, i2c_hand, 0x02, 0x00); //10FPS
}

exports.read_thermistor = async () => {
  let temp = await pig._i2c_read_word_data(pi, i2c_hand, 0x0e);
  return temp * 0.0625;
}

exports.read_temp_array = async () => {
  let linedata = [];
  for (let i = 0; i < 8; i++) {
    let data = await pig._i2c_read_i2c_block_data(pi, i2c_hand, 0x80 + 0x10 * i, 16);
    let oneline = [];
    for (let j = 0; j < 8; j++) {
      oneline.push(((data[2 * j + 1] & 0x07) * 256 + data[2 * j]) * 0.25);
    }
    linedata.push(oneline);
  }
  return linedata;
}

exports.stop = async () => {
  if (i2c_hand >= 0) {
    await pig._i2c_close(pi, i2c_hand);
    i2c_hand = -1;
  }
  if (pi >= 0) {
    await pig._rgpiod_stop(pi);
    pi = -1;
  }
}

/*
* This code was ported from https://www.denshi.club/pc/raspi/5raspberry-pi-zeroiot381i2c-amg8833.html
*/