'use strict';

const { parseXML, childAttr } = require('../parser');
const {
  createDoc,
  energyInteropNs,
  parseEiResponse,
  serializeEiResponse,
} = require('../shared');
const { fragment } = require('xmlbuilder2');

async function parse(input) {
  const json = await parseXML(input);
  const o =
    json['oadrPayload']['$$']['oadrSignedObject'][0]['$$']['oadrResponse'][0][
      '$$'
    ];

  const { code, description, requestId } = parseEiResponse(
    o['eiResponse'][0]['$$'],
  );

  const result = {
    _type: 'oadrResponse',
    responseCode: code,
    responseRequestId: requestId,
  };

  if (description != null) result.responseDescription = description;

  if (code < 200 || code >= 300) {
    return result;
  }

  const venId = childAttr(o, 'venID');
  if (venId != null) result.venId = venId;

  return result;
}

function validate(obj) {
  if (!obj.responseCode) {
    throw new Error('Missing responseCode');
  }
}

function serialize(obj) {
  validate(obj);

  const venId =
    obj.venId != null
      ? fragment()
        .ele(energyInteropNs, 'ei:venID')
        .txt(obj.venId)
      : fragment();

  const doc = createDoc()
    .ele('@oadr2b', 'oadr2b:oadrPayload')
    .ele('oadr2b:oadrSignedObject')
    .ele('oadr2b:oadrResponse')
    .att('@ei', 'ei:schemaVersion', '2.0b')
    .import(serializeEiResponse(obj))
    .import(venId)
    .doc();
  return doc.end({ headless: true, prettyPrint: false });
}

async function canParse(input) {
  const json = await parseXML(input);
  const o = json['oadrPayload']['$$']['oadrSignedObject'][0]['$$'];
  return o['oadrResponse'] != null;
}

function canSerialize(message) {
  return message._type === 'oadrResponse';
}

module.exports = {
  parse,
  serialize,
  canParse,
  canSerialize,
};