/*
 * decaffeinate suggestions:
 * DS101: Remove unnecessary use of Array.from
 * DS102: Remove unnecessary code created because of implicit returns
 * DS103: Rewrite code to no longer use __guard__
 * DS207: Consider shorter variations of null checks
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
let OutputFileFinder;
const async = require("async");
const fs = require("fs");
const Path = require("path");
const { spawn } = require("child_process");
const logger = require("logger-sharelatex");

module.exports = (OutputFileFinder = {
	findOutputFiles(resources, directory, callback) {
		if (callback == null) { callback = function(error, outputFiles, allFiles) {}; }
		const incomingResources = {};
		for (let resource of Array.from(resources)) {
			incomingResources[resource.path] = true;
		}
			
		return OutputFileFinder._getAllFiles(directory, function(error, allFiles) {
			if (allFiles == null) { allFiles = []; }
			if (error != null) {
				logger.err({err:error}, "error finding all output files");
				return callback(error);
			}
			const outputFiles = [];
			for (let file of Array.from(allFiles)) {
				if (!incomingResources[file]) {
					outputFiles.push({
						path: file,
						type: __guard__(file.match(/\.([^\.]+)$/), x => x[1])
					});
				}
			}
			return callback(null, outputFiles, allFiles);
		});
	},

	_getAllFiles(directory, _callback) {
		if (_callback == null) { _callback = function(error, fileList) {}; }
		const callback = function(error, fileList) {
			_callback(error, fileList);
			return _callback = function() {};
		};

		// don't include clsi-specific files/directories in the output list
		const EXCLUDE_DIRS = ["-name", ".cache", "-o", "-name", ".archive","-o", "-name", ".project-*"];
		const args = [directory, "(", ...Array.from(EXCLUDE_DIRS), ")", "-prune", "-o", "-type", "f", "-print"];
		logger.log({args}, "running find command");

		const proc = spawn("find", args);
		let stdout = "";
		proc.stdout.on("data", chunk => stdout += chunk.toString());	
		proc.on("error", callback);	
		return proc.on("close", function(code) {
			if (code !== 0) {
				logger.warn({directory, code}, "find returned error, directory likely doesn't exist");
				return callback(null, []);
			}
			let fileList = stdout.trim().split("\n");
			fileList = fileList.map(function(file) {
				// Strip leading directory
				let path;
				return path = Path.relative(directory, file);
			});
			return callback(null, fileList);
		});
	}
});


function __guard__(value, transform) {
  return (typeof value !== 'undefined' && value !== null) ? transform(value) : undefined;
}