Webhook.js

/*
 * This is a Webhook End-point for Watson Workspace. You will need to modify the credentials below
 * to contain the actual credentials for your Watson Workspace App.
 *
 * This action will perform all the necesary validation and hand-shaking to Watson Work Services.
 * Actual events will be published on the EventTrigger trigger
 * The following package parameters are used:
 * WWAppId - The Watson Workspace appId
 * WWAppSecret - The Watson Workspace App AppSecret
 * WWWebhookSecret - The Watson Workspace Webhook Secret
 * WWEventTopic - The name of the topic to send events to
 */

var crypto = require("crypto");
var openwhisk = require("openwhisk");
var util = require("util");
var _ = require("lodash");
var mustache = require("mustache");
var annotationGQL = {
    GraphQLExpansion: `
   query {
     message(id: "{{messageId}}") {
       content
       id
       created
       createdBy {
         displayName
         id
         emailAddresses
         photoUrl
       }
     }
   }`
};

var expansion = {
    "message-annotation-added": annotationGQL,
    "message-annotation-edited": annotationGQL,
    "message-annotation-removed": annotationGQL,
};

function samePackage(action) {
  return (process.env.__OW_ACTION_NAME.replace(/\/[^\/]+$/,"") + "/" + action).replace(/^\/[^\/]+\//,"");
}

async function expandEvent(body, params, ow) {
  // Check to see if there is an expansion GraphQL expression to run
  if (body.hasOwnProperty("type") && expansion.hasOwnProperty(body.type)) {
    var exp = expansion[body.type];
    var resp = await ow.actions.invoke({
      name: samePackage("GraphQL"),
      blocking: true,
      result: true,
      params: {
          string: mustache.render(exp.GraphQLExpansion, body)
      }
    });
    // If annotation, mark it as generated by my app if it was
    /* istanbul ignore else  */
    if (body.type.startsWith("message-annotation"))
      body.appEvent = resp.data.message.createdBy.id === params.AppId;

    return _.merge(body, resp.data);
  } else {
    return body;
  }
}

function cleanUpEvent(event, params) {
    // expand annotationPayload into JSON obejct if it exists.
    if (event.hasOwnProperty("annotationPayload") && typeof event.annotationPayload === "string")
        event.annotationPayload = JSON.parse(event.annotationPayload);

    // Was this event generated by my app?
    if (_.get(event,"annotationPayload.targetAppId"))
        event.appEvent = event.annotationPayload.targetAppId === params.AppId;
    else
        event.appEvent = event.userId === params.AppId;

    // Cleanup time field
    /* istanbul ignore else  */
    if (event.hasOwnProperty("time"))
        event.time = Date(event.time).toString();
}

function closeAction(annotation, params, ow) {
  var card = {
    type: 'INFORMATION',
    title: 'Action Completed',
    text: "You can close this action.",
    buttons: []
  };

  /* istanbul ignore else  */
  if (_.has(annotation,"annotationPayload.actionId.response")) {
    _.merge(card, annotation.annotationPayload.actionId.response);
  }

  ow.actions.invoke ({
    name: samePackage("TargetedMessage"),
    params: {cards: card, annotation: annotation}
  });
}

async function main(params) {
  var ow = openwhisk(
    _.get(params,"WatsonWorkspace.OWArgs",{})
  );
  var rawBody =Buffer.from(params.__ow_body, "base64").toString();
  var req = {
    rawBody: rawBody,
    body: JSON.parse(rawBody),
    headers: params.__ow_headers
  };

  // separate Workspace paramaters
  var workspaceParams = params.WatsonWorkspace;
  _.omit(params,"WatsonWorkspace");

  if (!validateSender(params, req)) {
    return Promise.reject({
      statusCode: 401,
      body: "Invalid Request Signature"
    });
  }
  if (_.get(req.body, "type") === "verification") {
    var body = {
      response: req.body.challenge
    };
    var strBody = JSON.stringify(body);
    var validationToken = crypto.createHmac("sha256", workspaceParams.WebhookSecret).update(strBody).digest("hex");
    return {
      statusCode: 200,
      headers: {
        "Content-Type": "text/plain; charset=utf-8",
        "X-OUTBOUND-TOKEN": validationToken
      },
      body: strBody
    };
  } else {

    // Clean up the event
    cleanUpEvent(req.body,workspaceParams);

    if (_.get(req.body, "annotationType") === "actionSelected" && req.body.appEvent) {
      var triggerName = "WWActionSelected";
      var prefix = "BUTTON_SELECTED: ";
      if (req.body.annotationPayload.actionId.startsWith(prefix)) {
        triggerName = "WWButtonSelected";
        var action = req.body.annotationPayload.actionId.substr(prefix.length)
        try {
          req.body.annotationPayload.actionId = JSON.parse(action);
        }
        catch (err) {
          req.body.annotationPayload.actionId = action;
        }
        closeAction(req.body, params.workspaceParams,ow);
      }
      // Send event to topic
      ow.triggers.invoke({
        name: triggerName,
        params: req.body
      })
      return {
        statusCode: 200,
        headers: {
          "Content-Type": "application/json"
        },
        body: {
          status: "OK!"
        }
      };
    }
    else {
      // Expand Event
      var body = await expandEvent(req.body, workspaceParams, ow);

      // Send event to topic
      /* istanbul ignore next */
      const target = body.appEvent ? "WWApplicationEvents" : "WWWebhookEvents";
      ow.triggers.invoke({
        name: target,
        params: body
      });
      return {
        statusCode: 200,
        headers: {
          "Content-Type": "application/json"
        },
        body: {
          status: "OK!"
        }
      };
    }
  }
}


function validateSender(params, req) {
    var ob_token = req.headers["x-outbound-token"];
    var calculated = crypto.createHmac("sha256", params.WatsonWorkspace.WebhookSecret).update(req.rawBody).digest("hex");
    return ob_token == calculated;
}

exports.main = main;
exports.setOpenwhisk = function(obj) {
  openwhisk = obj;
}