Source: core/create_collection.js

/*
 * This file is part of PKM (Persistent Knowledge Monitor).
 * Copyright (c) 2020 Capgemini Group, Commissariat à l'énergie atomique et aux énergies alternatives,
 *                    OW2, Sysgo AG, Technikon, Tree Technology, Universitat Politècnica de València.
 * 
 * PKM is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3 as published by
 * the Free Software Foundation.
 * 
 * PKM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with PKM.  If not, see <https://www.gnu.org/licenses/>.
 */

/**
 * Create collection
 * 
 * @memberof PKM
 * @instance
 * @param {string} dbName - database name
 * @param {string} collection_name - collection name
 * @param {Object} [collection_info] - collection info
 * 
 * @return {Promise} a promise
 */

function create_collection(dbName, collection_name, collection_info)
{
	return new Promise(function(resolve, reject)
	{
		const db = this.client.db(dbName);

		var collection_cursor = db.listCollections({ name : collection_name });
		
		let count = 0;
		
		collection_cursor.each((err, list_collections_result) =>
		{
			if(err)
			{
				reject(this.Error(err));
			}
			else if(list_collections_result)
			{
				++count;
			}
			else if(count)
			{
				reject(this.Conflict('Collection \'' + collection_name + '\' already exists in Database \'' + dbName + '\''));
			}
			else
			{
				db.createCollection(collection_name).then((collection) =>
				{
					if((collection_info === undefined) || (collection_info.index === undefined))
					{
						resolve(collection);
					}
					else
					{
						collection.createIndex(collection_info.index.key, collection_info.index.options).then(() =>
						{
							resolve(collection);
						}).catch((err) =>
						{
							reject(this.Error(err));
						});
					}
				}).catch((err) =>
				{
					reject(this.Error(err));
				});
			}
		});
	}.bind(this));
}

exports.create_collection = create_collection;