cli

#!/usr/bin/env node

/**
* @license Apache-2.0
*
* Copyright (c) 2019 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 ReadStream = require( 'tty' ).ReadStream;
var openSync = require( '@stdlib/fs/open' ).sync;
var closeSync = require( '@stdlib/fs/close' ).sync;
var readFileSync = require( '@stdlib/fs/read-file' ).sync;
var CLI = require( '@stdlib/cli/ctor' );
var stdin = require( '@stdlib/process/read-stdin' );
var stdinStream = require( '@stdlib/streams/node/stdin' );
var REPL = require( '@stdlib/repl' );
var lowercase = require( '@stdlib/string/lowercase' );
var IS_WINDOWS = require( '@stdlib/assert/is-windows' );
var Presentation = require( './../lib' ); // eslint-disable-line stdlib/no-redeclare


// MAIN //

/**
* Main execution sequence.
*
* @private
* @returns {void}
*/
function main() {
	var flags;
	var opts1;
	var opts2;
	var repl;
	var pres;
	var args;
	var cli;
	var err;

	// 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;
	}

	// Get any provided command-line arguments:
	args = cli.args();

	// Handle REPL options...
	opts1 = {};
	if ( typeof flags[ 'input-prompt' ] === 'string' ) {
		opts1.inputPrompt = flags[ 'input-prompt' ];
	}
	if ( flags.logfile ) {
		opts1.log = flags.logfile;
	}
	if ( typeof flags[ 'output-prompt' ] === 'string' ) {
		opts1.outputPrompt = flags[ 'output-prompt' ];
	}
	if ( flags.padding ) {
		opts1.padding = parseInt( flags.padding, 10 );
	}
	if ( flags.quiet ) {
		opts1.quiet = flags.quiet;
	}
	if ( flags.save ) {
		opts1.save = flags.save;
	}
	if ( flags.timeout ) {
		opts1.timeout = parseInt( flags.timeout, 10 );
	}

	// Handle presentation options...
	opts2 = {};
	if ( typeof flags[ 'border-top' ] === 'string' ) {
		opts2.borderTop = flags[ 'border-top' ];
	}
	if ( typeof flags[ 'border-bottom' ] === 'string' ) {
		opts2.borderBottom = flags[ 'border-bottom' ];
	}
	if ( typeof flags[ 'border-left' ] === 'string' ) {
		opts2.borderLeft = flags[ 'border-left' ];
	}
	if ( typeof flags[ 'border-right' ] === 'string' ) {
		opts2.borderRight = flags[ 'border-right' ];
	}
	if ( flags.width ) {
		opts2.width = parseInt( flags.width, 10 );
	}
	if ( flags.height ) {
		opts2.height = parseInt( flags.height, 10 );
	}
	if ( flags.workspace ) {
		opts2.workspace = flags.workspace;
	}
	if ( flags.counter ) {
		flags.counter = lowercase( flags.counter );
		if ( flags.counter === 'true' || flags.counter === 't' ) {
			opts2.counter = true;
		} else if ( flags.counter === 'false' || flags.counter === 'f' ) {
			opts2.counter = false;
		} else {
			opts2.counter = flags.counter;
		}
	}
	if ( flags.autoclear === false ) {
		opts2.autoClear = flags.autoclear;
	}
	if ( flags.loop ) {
		opts2.loop = flags.loop;
	}
	// Check if we are receiving data from `stdin`...
	if ( !stdinStream.isTTY ) {
		if ( IS_WINDOWS ) {
			err = new Error( 'invalid operation. Receiving data over `stdin` is not currently supported on Windows. Load a presentation from a file.' );
			return cli.error( err );
		}
		return stdin( onRead );
	}
	opts2.load = args[ 0 ];

	// Create a new REPL instance:
	repl = new REPL( opts1 );

	// Create a new REPL presentation:
	pres = new Presentation( repl, opts2 );

	// Render the first slide:
	pres.show();

	// Check whether to begin watching the source presentation file...
	if ( flags.watch ) {
		pres.on( 'change', onChange );
		pres.watch();
	}

	/**
	* Callback invoked upon a change to the source presentation file.
	*
	* @private
	*/
	function onChange() {
		pres.show();
	}

	/**
	* Callback invoked upon reading from `stdin`.
	*
	* @private
	* @param {(Error|null)} error - error object
	* @param {Buffer} text - text
	* @returns {void}
	*/
	function onRead( error, text ) {
		var repl;
		var pres;
		var fd;
		if ( error ) {
			return cli.error( error );
		}
		// Because we received input over `stdin`, we need to create a new TTY `stdin` read stream for receiving interactive user input...
		fd = openSync( '/dev/tty', 'r' );
		if ( fd instanceof Error ) {
			return cli.error( error );
		}
		opts1.input = new ReadStream( fd ); // note: instance of net.Socket

		// Create a new REPL instance:
		repl = new REPL( opts1 );
		repl.once( 'exit', onExit );

		// Create a new REPL presentation:
		pres = new Presentation( text.toString(), repl, opts2 );
		pres.show();

		/**
		* Callback invoked upon exiting a REPL.
		*
		* @private
		*/
		function onExit() {
			opts1.input.end(); // close socket to prevent the process from hanging (see https://github.com/nodejs/node-v0.x-archive/issues/7101)
			closeSync( fd );
		}
	}
}

main();