'use strict';

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

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

  const result = {
    _type: 'oadrRequestEvent',
    requestId: required(childAttr(o, 'requestID'), 'requestID'),
    venId: required(childAttr(o, 'venID'), 'venID'),
  };

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

  return result;
}

function serializeEiRequestEvent(requestId, venId, replyLimit) {
  const replyLimitFrag =
    replyLimit != null
      ? fragment()
        .ele(energyInteropPayloadsNs, 'pyld:replyLimit')
        .txt(replyLimit)
      : fragment();

  return fragment()
    .ele(energyInteropPayloadsNs, 'pyld:requestID')
    .txt(requestId)
    .up()
    .ele(energyInteropNs, 'ei:venID')
    .txt(venId)
    .up()
    .import(replyLimitFrag);
}

function serialize(obj) {
  const doc = createDoc()
    .ele('@oadr2b', 'oadr2b:oadrPayload')
    .ele('oadr2b:oadrSignedObject')
    .ele('oadr2b:oadrRequestEvent')
    .att(energyInteropNs, 'ei:schemaVersion', '2.0b')
    .ele('@pyld', 'pyld:eiRequestEvent')
    .import(serializeEiRequestEvent(obj.requestId, obj.venId, obj.replyLimit))
    .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['oadrRequestEvent'] != null;
}

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

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