Initial version

.gitignore

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+node_modules/

Arguments.js

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+var fs = require('fs'),
+	minimist = require('minimist');
+
+var defaults = {
+	fileSpec: [
+		{type: 'TOKEN', value: 'ARTIST'},
+		{type: 'TEXT',  value: ' - ', },
+		{type: 'TOKEN', value: 'ALBUM'},
+		{type: 'TEXT',  value: ' - '},
+		{type: 'TOKEN', value: 'TRACKNUM'} ],
+	subdirSpec: [],
+	rootDir: '.'
+}
+function assert(expr, message, ch, parts) {
+	if (!expr) {
+		console.log("ch=" + ch);
+		console.dir(parts);
+		throw message;
+	}
+}
+
+function processSpec(spec, trackInfo) {
+	var pieces;
+
+	// Loop through the parts...
+	return spec.map(function(token) {
+		// TEXT
+		if (token.type === 'TEXT') {
+			return token.value;
+		} else if (token.type === 'TOKEN') {
+			return trackInfo[token.value];
+		}
+	});
+}
+
+function parseSpec(s) {
+	var chars = s.split(''), 
+		parts = [],
+		inPercent = false,
+		part;
+
+	// Function to handle a new TEXT character...
+	function addTextChar(ch) {
+		// No part?
+		if (!part) {
+			part = { type: 'TEXT', value: ''};
+		}
+
+		// Verify that the part is TEXT
+		assert(part.type === 'TEXT', "Internal Error: Expecting part of type 'TEXT', but was '" + part.type + "'", ch, parts);
+
+		// Append to the value...
+		part.value += ch;
+	}
+
+	// Loop through each characters...
+	for (var i=0; i<chars.length; i++) {
+		// Are we "inside" a percent?
+		if (inPercent) {
+			// Verify that we are inside a TOKEN
+			assert(part && part.type === 'TOKEN', "Internal Error: Expecting part of type 'TOKEN', but was '" + part.type + "'");
+
+			// Are we looking at a percent?
+			if (chars[i] === '%') {
+				// Close the token...
+				parts.push(part);
+
+				// Delete the part...
+				part = undefined;
+
+				// No longer in percent...
+				inPercent = false;
+			} else {
+				// Add to existing part...
+				part.value += chars[i];
+			}
+		} else {
+			// Are we looking at a percent?
+			if (chars[i] === '%') {
+				// Is the next character also a percent?
+				if (i+1 < chars.length && chars[i+1] === '%') {
+					// Treat as a character...
+					addTextChar(chars[i]);
+
+					// Increment our counter...
+					i++;
+				}
+
+				// Is there a current part open?
+				else {
+					if (part) {
+						// Push the current part on the list...
+						parts.push(part);
+					}
+
+					// Create a new part
+					part = { type: 'TOKEN', value: '' };
+
+					// Indicate we are inside a percent...
+					inPercent = true;
+				}
+			}
+			else {
+				// Add character to text...
+				addTextChar(chars[i]);
+			}
+		}
+	}
+
+	// Do we have an open part?
+	if (part) {
+		// Verify that we are not inside a percent...
+		if (part.type === 'TOKEN') {
+			// Is it the last character?
+			if (part.value === '') {
+				throw "Including % at the end of a string. Please use %% to add a percent character.";
+			}
+
+			// Otherwise, some other problem...
+			throw "Missing '%' in token named: " + part.value;
+		}
+
+		// If we have an open part, it must be text...
+		assert(part.type === 'TEXT', "Internal Error: Expecting part of type 'TEXT', but was '" + part.type + "'");
+
+		// Add it!
+		parts.push(part);
+	}
+
+	return parts;
+}
+
+function parseDirSpec(s) {
+	// Parse it!
+	var parts = parseSpec(s);
+
+	// Verify that we have at least one part...
+	assert(parts.length > 0, "Internal Error: Unable to parse the string.");
+
+	// Verify each token...
+	parts.forEach(function(part) {
+		// Is a token?
+		if (part.type === 'TOKEN') {
+			// Check for valid token name...
+			// TODO Replace with Array.indexOf
+			if (!['ARTIST', 'ALBUM'].some(function(t) { return part.value === t; })) {
+				throw "Invalid token name: " + part.value;
+			}
+		}
+	});
+
+	return parts;
+}
+
+function parseFileSpec(s) {
+	// Parse it!
+	var parts = parseSpec(s);
+
+	// Verify that we have at least one part...
+	assert(parts.length > 0, "Internal Error: Unable to parse the string.");
+
+	// Verify each token...
+	parts.forEach(function(part) {
+		// Is a token?
+		if (part.type === 'TOKEN') {
+			// Check for valid token name...
+			if (!['ARTIST', 'ALBUM', 'TRACKNAME', 'TRACKNUM'].some(function(t) { return part.value === t; })) {
+				throw "Invalid token name: " + part.value;
+			}
+		}
+
+		// Is a text?
+		else if (part.type === 'TEXT') {
+			if (part.value.indexOf("/") >= 0) {
+				throw "Slashes not allowed in file specification."
+			}
+		}
+	});
+
+	return parts;
+}
+
+function Arguments(args) {
+	this.args = args;
+	this.argv = new minimist(args);
+}
+
+Arguments.prototype.usage = function() {
+	var scriptName = ((process.argv[1].split("/")).reverse())[0];
+
+	console.log("Usage: %s [options]\n", scriptName);
+	console.log("--watch-dir WD:         Monitor directory 'WD' for .emx files that are added to it.");
+	console.log("                        No default--must be specified.\n");
+	console.log("--root-dir RD:          Save downloaded music files into root directory 'RD'.");
+	console.log("                        If omitted, defaults to the current working directory.\n");
+	console.log("--sub-dir-spec DIRSPEC: Specifies how directories under the root directory are")
+	console.log("                        created, based on dynamic tags, such as Album name or");
+	console.log("                        Artist name. See 'Subdirectory Specification' for details.");
+	console.log("                        If omitted, no subdirectories are created. All music files");
+	console.log("                        are saved into the root directory.\n");
+	console.log("--file-spec FILESPEC:   Specifies how music files under the subdirectories are")
+	console.log("                        created, based on dynamic tags, such as Track Name, Track");
+	console.log("                        Number, or other static text. See 'File Naming Specification'");
+	console.log("                        for details.");
+	console.log("                        If omitted, defaults to '%ARTIST% - %ALBUM% - %TRACKNUM%'\n");
+	console.log("For more details, see https://github.com/gboysko/emusic-dlm");
+
+	// Exit!
+	process.exit();
+};
+
+Arguments.prototype.process = function() {
+	// No command line arguments? 
+	if (this.args.length === 0) {
+		this.usage();
+	}
+
+	// Check for validity of the watch directory...
+	if (!this.argv["watch-dir"]) {
+		console.log("--watch-dir is omitted.");
+		this.usage();
+	}
+	try {
+		// Get stats for the argument...
+		var stats = fs.statSync(this.argv["watch-dir"]);
+
+		// Is it a directory?
+		if (!stats.isDirectory()) {
+			console.log("The value to --watch-dir is not a directory: %s", this.argv["watch-dir"]);
+			this.usage();
+		}
+
+		// Remove it...
+		this.watchDir = this.argv["watch-dir"];
+		delete this.argv["watch-dir"];
+	} catch (err) {
+		console.log("--watch-dir does not refer to an existing directory: %s", this.argv["watch-dir"]);
+		this.usage();
+	}
+
+	// Check for validity of the root directory...
+	if (this.argv["root-dir"]) {
+		try {
+			// Get stats for the argument...
+			var stats = fs.statSync(this.argv["root-dir"]);
+
+			// Is it a directory?
+			if (!stats.isDirectory()) {
+				console.log("The value to --root-dir is not a directory: %s", this.argv["root-dir"]);
+				this.usage();
+			}
+
+			// Remove it...
+			this.rootDir = this.argv["root-dir"];
+			delete this.argv["root-dir"];
+		} catch (err) {
+			console.log("--root-dir does not refer to an existing directory: %s", this.argv["root-dir"]);
+			this.usage();
+		}
+	}
+
+	// Check for validity of the subdirectory specification...
+	if (this.argv["sub-dir-spec"]) {
+		try {
+			// Parse the argument into parts...
+			this.subDirSpec = parseDirSpec(this.argv["sub-dir-spec"]);
+
+			// Remove it...
+			delete this.argv["sub-dir-spec"];
+		} catch (err) {
+			console.log("--sub-dir-spec is invalid:", err);
+			this.usage();
+		}
+	}
+
+	// Check for validity of the file specification...
+	if (this.argv["file-spec"]) {
+		try {
+			// Parse the argument into parts...
+			this.fileSpec = parseFileSpec(this.argv["file-spec"]);
+
+			// Remove it...
+			delete this.argv["file-spec"];
+		} catch (err) {
+			console.log("--file-spec is invalid:", err);
+			this.usage();
+		}
+	}
+
+	// Any remaining arguments?
+	if (this.argv._.length > 0) {
+		console.log("Extra command line arguments:", this.argv._.join(" "));
+		this.usage();
+	}
+
+	// Remove array...
+	delete this.argv._;
+
+	// Any other arguments?
+	for (var n in this.argv) {
+		console.log("Unexpected flags:", Object.keys(this.argv).join(", "));
+		this.usage();
+	}
+};
+
+Arguments.prototype.getRootDir = function() {
+	return this.rootDir || defaults.rootDir;
+};
+
+Arguments.prototype.getWatchDir = function() {
+	return this.watchDir;
+};
+
+Arguments.prototype.getFileSpec = function() {
+	return this.fileSpec || defaults.fileSpec;
+};
+
+Arguments.prototype.getSubdirSpec = function() {
+	return this.subDirSpec || defaults.subdirSpec;
+};
+
+Arguments.prototype.getFileName = function(trackInfo) {
+	return processSpec(this.getFileSpec(), trackInfo).concat(trackInfo.EXTENSION).join("");
+};
+
+Arguments.prototype.getSubdirName = function(trackInfo) {
+	return [this.getRootDir(), processSpec(this.getSubdirSpec(), trackInfo).join("")].join("/");
+}
+
+module.exports = Arguments;