Source: core/postprocess_files.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/>.
 */

/** Postprocess Files. Merge file chunk documents into file documents.
 * 
 * @memberof PKM
 * @instance
 * @param {string} dbName - Database name
 * @param {Array.<Object>} file_chunk_documents - File chunk documents
 * @param {Object} [options] - options
 * 
 * @return {Promise<Array.<Object>>} a promise
 */
function postprocess_files(file_chunk_documents, options = {})
{
	return new Promise(function(resolve, reject)
	{
		let file_documents = [];
		
		// the file chunk document may be out-of-order, so we first need to reorder the chunks for each filename
		let chunks_per_filename = new Map();
		file_chunk_documents.forEach((file_chunk_document) =>
		{
			if(chunks_per_filename.has(file_chunk_document.filename))
			{
				let chunks = chunks_per_filename.get(file_chunk_document.filename);
				if(!file_chunk_document.hasOwnProperty('chunkId'))
				{
					throw Error('File database object named ' + file_chunk_document.filename + ' has no chunk field');
				}
				if(file_chunk_document.chunkId > chunks.length)
				{
					while(file_chunk_document.chunkId > chunks.length) chunks.push(undefined); // expand chunks array with holes (holes shall vanish before the end of the process)
					chunks.push(file_chunk_document);
				}
				else
				{
					chunks[file_chunk_document.chunkId] = file_chunk_document;
				}
			}
			else
			{
				let chunks = [];
				if(file_chunk_document.hasOwnProperty('chunkId'))
				{
					while(file_chunk_document.chunkId > chunks.length) chunks.push(undefined); // expand chunks array with holes (holes shall vanish before the end of the process)
				}
				chunks.push(file_chunk_document);
				chunks_per_filename.set(file_chunk_document.filename, chunks);
			}
		});
		
		// for each filename
		Array.from(chunks_per_filename.keys()).forEach((filename) =>
		{
			let chunks = chunks_per_filename.get(filename);
			let fileFormat;
			let has_filecontent;
			
			// check that the integrity of chunks, in particular that there are no holes, that file format and content presence are coherent among the chunks
			chunks.forEach((chunk) =>
			{
				if(chunk === undefined)
				{
					throw Error('File chunks for ' + filename + ' have holes');
				}
				
				if(fileFormat === undefined)
				{
					fileFormat = chunk.fileFormat;
				}
				if(has_filecontent === undefined)
				{
					has_filecontent = (chunk.filecontent !== undefined);
				}
				
				if(chunk.fileFormat !== fileFormat)
				{
					throw Error('File chunks for ' + filename + ' have different formats');
				}
				
				if(has_filecontent ^ (chunk.filecontent !== undefined))
				{
					throw Error('some File chunks for ' + filename + ' have contents, some others have not');
				}
			});
			
			// merge content of the chunks
			let file_chunk_document = chunks[0];
			let file_document =
			{
				filecontent : ((file_chunk_document.filecontent !== undefined) ? chunks.map((chunk) => chunk.filecontent).join('') : undefined),
			};
			[ 'filename', 'fileType', 'fileMimeType', 'fileFormat', 'fileEncoding', 'gitWorkingTree', 'gitDirty', 'gitUnmerged' ].forEach((key) =>
			{
				if(file_chunk_document[key] !== undefined)
				{
					file_document[key] = file_chunk_document[key];
				}
			});
			
			file_documents.push(file_document);
		});
		
		// serve the file documents
		resolve(file_documents);
	}.bind(this));
}

module.exports.postprocess_files = postprocess_files;