cli

#!/usr/bin/env node

/**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

'use strict';

// MODULES //

var resolve = require( 'path' ).resolve;
var readFileSync = require( '@stdlib/fs/read-file' ).sync;
var indexOf = require( '@stdlib/utils/index-of' );
var CLI = require( '@stdlib/cli/ctor' );
var namespace = require( './../lib' );


// VARIABLES //

var FIELDS = [ 'alias', 'path', 'type', 'related' ];


// FUNCTIONS //

/**
* Prints data as newline-delimited JSON (ndjson).
*
* @private
* @param {ObjectArray} data - data to print
*/
function ndjson( data ) {
	var i;

	for ( i = 0; i < data.length; i++ ) {
		console.log( JSON.stringify( data[i] ) );
	}
}

/**
* Prints data as lines of comma-separated values (CSV).
*
* @private
* @param {ObjectArray} data - data to print
* @param {StringArray} fields - output fields
*/
function csv( data, fields ) {
	var line;
	var f;
	var i;
	var j;
	var n;
	var m;

	n = fields.length;
	m = n - 1;
	line = '';
	for ( j = 0; j < n; j++ ) {
		line += '"' + fields[ j ] + '"';
		if ( j < m ) {
			line += ',';
		}
	}
	console.log( line );
	for ( i = 0; i < data.length; i++ ) {
		line = '';
		for ( j = 0; j < n; j++ ) {
			f = fields[ j ];
			line += '"' + data[ i ][ f ] + '"';
			if ( j < m ) {
				line += ',';
			}
		}
		console.log( line );
	}
}


// MAIN //

/**
* Main execution sequence.
*
* @private
* @returns {void}
*/
function main() {
	var fields;
	var flags;
	var cli;
	var err;
	var i;

	// Create a command-line interface:
	cli = new CLI({
		'pkg': require( './../package.json' ),
		'options': require( './../etc/cli_opts.json' ),
		'help': readFileSync( resolve( __dirname, '..', 'docs', 'usage.txt' ), {
			'encoding': 'utf8'
		})
	});

	// Get any provided command-line options:
	flags = cli.flags();
	if ( flags.help || flags.version ) {
		return;
	}
	if ( flags.fields ) {
		fields = flags.fields.split( ',' );
		for ( i = 0; i < fields.length; i++ ) {
			if ( indexOf( FIELDS, fields[ i ] ) === -1 ) {
				err = new Error( 'invalid option. Unrecognized/unsupported field. Option: `' + fields[ i ] + '`.' );
				return cli.error( err );
			}
		}
		return csv( namespace(), fields );
	}
	ndjson( namespace() );
}

main();