const InboundCallSession = require('./inbound-call-session');
const {createSipRecPayload} = require('../utils/siprec-utils');
const {CallStatus} = require('../utils/constants');
const {parseSiprecPayload} = require('../utils/siprec-utils');
const {JAMBONES_HOLD_UNHOLD_EVENTS} = require('../config');
/**
 * @classdesc Subclass of InboundCallSession.  This represents a CallSession that is
 * established for an inbound SIPREC call.
 * @extends InboundCallSession
 */
class SipRecCallSession extends InboundCallSession {
  constructor(req, res) {
    super(req, res);

    const {sdp1, sdp2, metadata} = req.locals.siprec;
    this.sdp1 = sdp1;
    this.sdp2 = sdp2;
    this.metadata = metadata;
  }

  async _onReinvite(req, res) {
    try {
      this.logger.info(req.payload, 'SipRec Re-INVITE payload');
      const {sdp1: reSdp1, sdp2: reSdp2, metadata: reMetadata} = await parseSiprecPayload(req, this.logger);
      this.sdp1 = reSdp1;
      this.sdp2 = reSdp2;
      this.metadata = reMetadata;

      if (this.ep && this.ep2) {
        let remoteSdp = this.sdp1.replace(/sendonly/, 'sendrecv');
        const newSdp1 = await this.ep.modify(remoteSdp);
        remoteSdp = this.sdp2.replace(/sendonly/, 'sendrecv');
        const newSdp2 = await this.ep2.modify(remoteSdp);
        const combinedSdp = await createSipRecPayload(newSdp1, newSdp2, this.logger);
        res.send(200, {body: combinedSdp});
        this.logger.info({offer: req.body, answer: combinedSdp}, 'SipRec handling reINVITE');
        this._notifySipRecReinvite(req, this.sdp1, this.sdp2);
      }
      else {
        this.logger.info('got SipRec reINVITE but no endpoint and media has not been released');
        res.send(488);
      }
    } catch (err) {
      this.logger.error(err, 'Error handling reinvite');
    }
  }

  /**
   * Notify the application of a SIPREC re-INVITE. SIPREC recording streams are
   * sendonly by nature, so a stream flipping to a=inactive is treated as the
   * (best-effort) hold signal; the full multipart body (SDP + rs-metadata) is
   * always forwarded so the app can determine hold from the metadata itself.
   * Delivered over the existing sipRequestWithinDialogHook channel; also emits
   * a local 'hold'/'unhold' on transition (for optional transcribe auto-pause).
   * Opt-in: only runs when JAMBONES_HOLD_UNHOLD_EVENTS is set.
   */
  _notifySipRecReinvite(req, sdp1, sdp2) {
    if (!JAMBONES_HOLD_UNHOLD_EVENTS) return;
    const onHold = /a=inactive/.test(sdp1 || '') || /a=inactive/.test(sdp2 || '');
    const changed = onHold !== !!this._onHold;
    this._onHold = onHold;
    if (changed) {
      const event = onHold ? 'hold' : 'unhold';
      this.logger.info({event, callSid: this.callSid}, 'SipRecCallSession: hold state changed');
      this.emit(event);
    }
    // Delivered via requestor.request('verb:hook', ...) — task-independent, so
    // the event survives even if the current task has ended (e.g. transcribe
    // failed on a speech-credential error). callInfo.toJSON() merged in manually.
    if (this.sipRequestWithinDialogHook && this.requestor) {
      const params = {
        ...(this.callInfo.toJSON()),
        sip_method: 'INVITE',
        siprec: true,
        event: changed ? (onHold ? 'hold' : 'unhold') : 'reinvite',
        on_hold: onHold,
        sip_body: req.body,        // full multipart: SDP parts + rs-metadata XML
        sip_headers: req.headers
      };
      this.requestor.request('verb:hook', this.sipRequestWithinDialogHook, params)
        .catch((err) => this.logger.error({err}, 'SipRecCallSession:_notifySipRecReinvite - hook error'));
    }
  }

  async answerSipRecCall() {
    try {
      let remoteSdp = this.sdp1.replace(/sendonly/, 'sendrecv');
      this.ep = await this._createMediaEndpoint({remoteSdp});
      //this.logger.debug({remoteSdp, localSdp: this.ep.local.sdp}, 'SipRecCallSession - allocated first endpoint');
      remoteSdp = this.sdp2.replace(/sendonly/, 'sendrecv');
      this.ep2 = await this._createMediaEndpoint({remoteSdp});
      //this.logger.debug({remoteSdp, localSdp: this.ep2.local.sdp}, 'SipRecCallSession - allocated second endpoint');
      await this.ep.bridge(this.ep2);
      const combinedSdp = await createSipRecPayload(this.ep.local.sdp, this.ep2.local.sdp, this.logger);
      /*
      this.logger.debug({
        combinedSdp
      }, 'SipRecCallSession:_answerSipRecCall - created SIPREC payload');
      */
      this.dlg = await this.srf.createUAS(this.req, this.res, {
        headers: {
          'Content-Type': 'application/sdp',
          'X-Trace-ID': this.req.locals.traceId,
          'X-Call-Sid': this.req.locals.callSid,
          ...(this.applicationSid && {'X-Application-Sid': this.applicationSid})
        },
        localSdp: combinedSdp
      });
      this.dlg.on('destroy', this._callerHungup.bind(this));
      this.wrapDialog(this.dlg);
      this.dlg.callSid = this.callSid;
      this.emit('callStatusChange', {sipStatus: 200, sipReason: 'OK', callStatus: CallStatus.InProgress});

      this.dlg.on('modify', this._onReinvite.bind(this));
      this.dlg.on('refer', this._onRefer.bind(this));
    } catch (err) {
      this.logger.error({err}, 'SipRecCallSession:_answerSipRecCall error:');
      if (this.res && !this.res.finalResponseSent) this.res.send(500);
      this._callReleased();
    }
  }
}

module.exports = SipRecCallSession;