var DiscoveryV1 = require('watson-developer-cloud/discovery/v1');

/**
 * Queries a Watson Discovery collection
 *
 * @param   {String} username
 * @param   {String} password
 * @param   {String} environment_id
 * @param   {String} collection_id
 * @param   {String} query
 *
 * @returns {Promise}
 */

function main(params) {

  var discovery = new DiscoveryV1({
    username: params.username,
    password: params.password,
    version_date: '2017-11-07'
  });

  return new Promise(function(resolve, reject) {
    discovery.query({
      environment_id: params.environment_id,
      collection_id: params.collection_id,
      query: params.query
    }, function(err, response) {
      if (err) {
        console.error(err);
        reject(err);
      } else {
        resolve(response);
      }
    });
  });
}