const MUTEX_COMMAND = 'COMMAND';

  exports.MUTEX_COMMAND = MUTEX_COMMAND;

  const MUTEX_SUBCOMMAND = 'SUBCOMMAND';

  exports.MUTEX_SUBCOMMAND = MUTEX_SUBCOMMAND;

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

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

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

  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.writeToPortAndWaitForReadline = 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.writeToPortAndWaitForOkOrError = 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.sleep = function sleep(ms) {
      return new Promise((resolve) => {
          setTimeout(() => {
              resolve();
          }, ms || 0);
      });
  };

  exports.setPort = function setPort(val) {
      port = val;
  };
  
  exports.querySignalQuality = 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.queryCOPS = 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.queryCOPSAndSignalQuality = 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 this.writeToPortAndWaitForOkOrError('AT+COPS?\r', MUTEX_SUBCOMMAND);
          await this.writeToPortAndWaitForOkOrError('AT+CSQ\r', MUTEX_SUBCOMMAND);

  
          mutex.unlock(MUTEX_COMMAND, 'queryCopsAndSignalQuality');

          resolve(true);
      });
  };

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

      const imei = await this.queryIMEI(MUTEX_SUBCOMMAND);
      const imsi = await this.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');
      });
  };
  
  exports.sendSMS = function sendSMS(destination, msg) {
      return new Promise(async (resolve) => {
          
      });
  };

  exports.initATCommands = async function initATCommands() {
      await mutex.lock(MUTEX_COMMAND, 'INIT MODEM');

      await this.writeToPortAndWaitForOkOrError('\rATE0\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');
  };