/**
   * Modul modem-commands
   *
   * @module
   */

  const MUTEX_COMMAND = 'COMMAND';

  exports.MUTEX_COMMAND = MUTEX_COMMAND;

  const MUTEX_SUBCOMMAND = 'SUBCOMMAND';

  exports.MUTEX_SUBCOMMAND = MUTEX_SUBCOMMAND;

  /**
   * CTRL-Z string
   * @constant
   */

  const CTRLZ = '\u001a';

  exports.CTRLZ = CTRLZ;

  const pdu = require('node-pdu');

  const uuidv1 = require('uuid/v1');

  const ParserReadline = require('@serialport/parser-readline');

  const ParserRegex = require('@serialport/parser-regex');

  const ParserReady = require('@serialport/parser-ready');

  const logger = require('komodo-sdk/logger');

  const mutex = require('../mutex-common');
  const parsers = require('../serialport-parsers');
  const modemInfo = require('../modem-info');

  
  let port;
  
  function writeToPort(data) {
      return new Promise((resolve) => {

          modemInfo.lastWriteTs = new Date();

          port.write(data, (err, bytesWritten) => {
              if (err) logger.warn(`ERROR: ${err.toString()}`);

              logger.verbose('OUTGOING', { data: data.toString(), bytesWritten, err });

              resolve(bytesWritten);
          });
      });
  }

  exports.writeToPort = writeToPort;

  function writeToPortAndWaitForReadline(cmd, lockName) {

      let resolved = false;

      return new Promise(async (resolve) => {
          const parser = new ParserReadline({ delimiter: parsers.PARSER_READLINE_DELIMITER });
          parser.on('data', (data) => {

              port.unpipe(parser);
              mutex.unlock(lockName || MUTEX_COMMAND, cmd.trim());

              if (!resolved) {
                  resolved = true;
                  resolve(data);
              }

          });
  
          await mutex.lock(lockName || MUTEX_COMMAND, cmd.trim());
          port.pipe(parser);
          await writeToPort(cmd);
      });

  }
  exports.writeToPortAndWaitForReadline = writeToPortAndWaitForReadline;

  function writeToPortAndWaitForOkOrError(cmd, lockName) {

      return new Promise(async (resolve) => {

          const parser = new ParserRegex({ regex: /(?:OK|ERROR)\r
  / });

          parser.on('data', (data) => {

              port.unpipe(parser);
              mutex.unlock(lockName || MUTEX_COMMAND, cmd.trim());
              resolve(data);
          });
  
          await mutex.lock(lockName || MUTEX_COMMAND, cmd.trim());
          port.pipe(parser);
          await writeToPort(cmd);
      });

  }
  exports.writeToPortAndWaitForOkOrError = writeToPortAndWaitForOkOrError;

  function sleep(ms) {

      return new Promise((resolve) => {
          setTimeout(() => {
              resolve();
          }, ms || 0);
      });

  }
  exports.sleep = sleep;

  exports.setPort = function setPort(val) {
      port = val;
  };

  function querySignalQuality() {

      return new Promise(async (resolve) => {
          if (!mutex.tryLock(MUTEX_COMMAND, 'querySignalQuality')) {
              resolve(false);
              return;
          }
  
          await writeToPort('AT+CSQ\r');
          mutex.unlock(MUTEX_COMMAND, 'querySignalQuality');
          resolve(true);
      });

  }
  exports.querySignalQuality = querySignalQuality;

  function queryCOPS(lockName) {

      return new Promise(async (resolve) => {

          await mutex.lock(lockName || MUTEX_COMMAND, 'queryCOPS');

          await writeToPort('AT+COPS?\r');

          mutex.unlock(lockName || MUTEX_COMMAND, 'queryCOPS');
          resolve(true);
      });

  }
  exports.queryCOPS = queryCOPS;

  function queryCOPSAndSignalQuality(skipOnLocked) {

      return new Promise(async (resolve) => {

          if (!skipOnLocked) {
              await mutex.lock(MUTEX_COMMAND);
          } else if (!mutex.tryLock(MUTEX_COMMAND, 'queryCOPSAndSignalQuality')) {

              resolve(false);
              return;
          }

          await writeToPortAndWaitForOkOrError('AT+COPS?\r', MUTEX_SUBCOMMAND);
          await writeToPortAndWaitForOkOrError('AT+CSQ\r', MUTEX_SUBCOMMAND);

  
          mutex.unlock(MUTEX_COMMAND, 'queryCopsAndSignalQuality');

          resolve(true);
      });

  }
  exports.queryCOPSAndSignalQuality = queryCOPSAndSignalQuality;

  function queryIMEI(lockName) {

      return new Promise(async (resolve) => {
          const parser = new ParserRegex({ regex: parsers.PARSER_WAIT_FOR_OK_OR_ERROR_REGEX });
          parser.on('data', (data) => {

              logger.verbose('INCOMING', { data: data.toString(), parser: 'parserIMEI' });

              port.unpipe(parser);

              mutex.unlock(lockName || MUTEX_COMMAND, 'queryIMEI');

              modemInfo.imei = data.toString().trim() || null;

              logger.info('IMEI extracted', { imei: modemInfo.imei });

              resolve(modemInfo.imei);

          });

          await mutex.lock(lockName || MUTEX_COMMAND, 'queryIMEI');

  
          port.pipe(parser);
          await writeToPort('AT+CGSN\r');

      });

  }
  exports.queryIMEI = queryIMEI;

  function queryIMSI(lockName) {

      return new Promise(async (resolve) => {
          const parser = new ParserRegex({ regex: parsers.PARSER_WAIT_FOR_OK_OR_ERROR_REGEX });
          parser.on('data', (data) => {

              logger.verbose('INCOMING', { data: data.toString(), parser: 'parserIMSI' });

              port.unpipe(parser);

              mutex.unlock(lockName || MUTEX_COMMAND, 'queryIMSI');

              modemInfo.imsi = data.toString().trim() || null;

              logger.info('IMSI extracted', { imsi: modemInfo.imsi });

              resolve(modemInfo.imsi);
          });

          await mutex.lock(lockName || MUTEX_COMMAND, 'queryIMSI');

  
          port.pipe(parser);
          await writeToPort('AT+CIMI\r');
      });

  }
  exports.queryIMSI = queryIMSI;

  
  exports.queryIMEIAndIMSI = async function queryIMEIAndIMSI() {
      await mutex.lock(MUTEX_COMMAND, 'queryIMEIAndIMSI');

      const imei = await queryIMEI(MUTEX_SUBCOMMAND);
      const imsi = await queryIMSI(MUTEX_SUBCOMMAND);

      await mutex.unlock(MUTEX_COMMAND, 'queryIMEIAndIMSI');

      return { imei, imsi };

  };

  exports.queryManufacturer = function queryManufacturer(lockName) {
      return new Promise(async (resolve) => {
          const parser = new ParserRegex({ regex: parsers.PARSER_WAIT_FOR_OK_OR_ERROR_REGEX });
          parser.on('data', (data) => {
              logger.verbose('INCOMING', { data: data.toString(), parser: 'parserManufacturer' });
              port.unpipe(parser);
              mutex.unlock(lockName || MUTEX_COMMAND, 'parserManufacturer');
              modemInfo.manufacturer = data.toString().trim() || null;
              logger.info('Manufacturer extracted', { manufacturer: modemInfo.manufacturer });
              resolve(modemInfo.manufacturer);
          });
  
          await mutex.lock(lockName || MUTEX_COMMAND, 'queryManufacturer');
  
          port.pipe(parser);
          await writeToPort('AT+CGMI\r');
      });
  };
  
  exports.queryModel = function queryModel(lockName) {
      return new Promise(async (resolve) => {
          const parser = new ParserRegex({ regex: parsers.PARSER_WAIT_FOR_OK_OR_ERROR_REGEX });
          parser.on('data', (data) => {
              logger.verbose('INCOMING', { data: data.toString(), parser: 'parserModel' });
              port.unpipe(parser);
              mutex.unlock(lockName || MUTEX_COMMAND, 'parserModel');
              modemInfo.model = data.toString().trim() || null;
              logger.info('Model extracted', { model: modemInfo.model });
              resolve(modemInfo.model);
          });
  
          await mutex.lock(lockName || MUTEX_COMMAND, 'queryModel');
  
          port.pipe(parser);
          await writeToPort('AT+CGMM\r');
      });
  };

  async function sendCtrlZ() {
      await writeToPort(CTRLZ);
  }
  exports.sendCtrlZ = sendCtrlZ;

  async function initATCommands() {

      await mutex.lock(MUTEX_COMMAND, 'INIT MODEM');

      await this.writeToPortAndWaitForOkOrError(`${CTRLZ}ATE0\r`, MUTEX_SUBCOMMAND);

      await this.writeToPortAndWaitForOkOrError('AT+CMGF=0\r', MUTEX_SUBCOMMAND);
      await this.writeToPortAndWaitForOkOrError('AT+CNMI=1,2,0,1,0\r', MUTEX_SUBCOMMAND);
      mutex.unlock(MUTEX_COMMAND, 'INIT MODEM');

  }
  exports.initATCommands = initATCommands;
  
  function sendCMGSPdu(pduLength) {
      return new Promise((resolve) => {
          const parser = new ParserReady({ delimiter: '>' });
          parser.on('data', () => {
              logger.verbose('Got ">" message prompt, gonna to write PDU message');
              port.unpipe(parser);
              mutex.unlock(MUTEX_SUBCOMMAND, 'sendSmsPduCommand');
              resolve(true);
          });
  
          mutex.lock(MUTEX_SUBCOMMAND, 'sendSmsPduCommand');
          port.pipe(parser);
          writeToPort(`AT+CMGS=${pduLength}\r`);
      });
  }
  
  exports.sendSMS = function sendSMS(destination, msg) {
      return new Promise(async (resolve) => {

          async function responseHandler(data) {
              logger.verbose('SMS sent callback called', { data });

  
              if (data.indexOf('ERROR') >= 0 || data.indexOf('+CMS ERROR') >= 0 || data.indexOf('+CMGS') >= 0) {
                  logger.verbose('SMS sent');
                  parsers.setSmsSentCallback(null);
                  mutex.unlock(MUTEX_COMMAND, 'sendSMS');
                  resolve(data.indexOf('ERROR') >= 0 ? null : data.toString().trim());
              }

          }

          await mutex.lock(MUTEX_COMMAND, 'sendSMS');
  
          if (!destination || !destination.trim()) {
              resolve(false);
              return;
          }
  
          if (!msg || !msg.trim()) {
              resolve(false);
              return;
          }
  
          const correctedDestination = `+${destination.replace(/^0/, '62')}`.replace(/^\++/, '+');
          logger.verbose(`Sending sms to ${correctedDestination}`, { msg });
  
          await this.writeToPortAndWaitForOkOrError('AT+CMGF=0\r', MUTEX_SUBCOMMAND);
  
          const submit = pdu.Submit();
          submit.setAddress(correctedDestination);
          submit.setData(msg.trim());
          submit.getType().setSrr(0);
  
          await sendCMGSPdu(Math.floor(submit.toString().length / 2) - 1);

          // await writeToPortAndWaitForOkOrError(`${submit.toString()}${CTRLZ}`, MUTEX_SUBCOMMAND);

          parsers.setSmsSentCallback(responseHandler);
          await writeToPort(`${submit.toString()}${CTRLZ}`, MUTEX_SUBCOMMAND);

      });
  };
  
  exports.executeUSSD = function executeUSSD(code, _includeCUSD2, _sessionId) {
      return new Promise(async (resolve) => {
          const includeCUSD2 = _includeCUSD2 || 0;
          const sessionId = _sessionId || uuidv1();
  
          async function responseHandler(data) {
              logger.verbose('Processing USSD response', { data });
              parsers.setUssdCallback(null);
  
              if (includeCUSD2 === 1 || includeCUSD2 === 2) {
                  await writeToPortAndWaitForOkOrError('AT+CUSD=2\r', MUTEX_SUBCOMMAND);
              }
  
              mutex.unlock(MUTEX_COMMAND, `executeUSSD ${sessionId}`);
              resolve(data);
          }
  
          mutex.lock(MUTEX_COMMAND, `executeUSSD ${sessionId}`);
          parsers.setUssdCallback(responseHandler);
  
          await this.writeToPortAndWaitForOkOrError(`${CTRLZ}AT+CMGF=0\r`, MUTEX_SUBCOMMAND);
  
          if (includeCUSD2 === -1 || includeCUSD2 === 2) {
              await this.writeToPortAndWaitForOkOrError('AT+CUSD=2\r', MUTEX_SUBCOMMAND);
          }
  
          await writeToPort(`AT+CUSD=1,"${code}",15\r`, MUTEX_SUBCOMMAND);
      });

  };