#!/usr/bin/env node
'use strict';

// MODULES //

var fs = require( 'fs' );
var path = require( 'path' );
var spawn = require( 'child_process' ).spawn;
var parseArgs = require( 'minimist' );
var notifier = require( 'update-notifier' );
var pkg = require( './../package.json' );
var opts = require( './opts.json' );
var commands = require( './commands.json' );


// FUNCTIONS //

/**
* Performs initialization tasks.
*
* @private
* @example
* init();
*/
function init() {
	var opts;

	// Check if newer versions exist for this package:
	opts = {
		'pkg': pkg
	};
	notifier( opts ).notify();

	// Set the process title to allow the process to be more easily identified:
	process.title = pkg.name;
	process.stdout.on( 'error', process.exit );
} // end FUNCTION init()

/**
* Prints usage information.
*
* @private
* @example
* help();
* // => '...'
*/
function help() {
	var fpath = path.join( __dirname, 'usage.txt' );
	fs.createReadStream( fpath )
		.pipe( process.stdout )
		.on( 'close', onClose );

	function onClose() {
		process.exit( 0 );
	}
} // end FUNCTION help()

/**
* Prints the package version.
*
* @private
* @example
* version();
* // => '#.#.#'
*/
function version() {
	var msg = pkg.version.toString()+'\n';
	process.stdout.write( msg, 'utf8' );
	process.exit( 0 );
} // end FUNCTION version()

/**
* Callback invoked upon encountering an error while running a command.
*
* @private
* @param {Error} error - error object
* @throws {Error} unexpected error
*/
function onError( error ) {
	throw error;
} // end FUNCTION onError()


// VARIABLES //

var args1;
var args2;
var proc;
var cmd;
var i;


// MAIN //

init();

// Parse command-line arguments:
args1 = parseArgs( process.argv.slice( 2 ), opts );

if ( args1.version ) {
	return version();
}
cmd = args1._[ 0 ];

opts = {
	'cwd': process.cwd(),
	'env': process.env,
	'stdio': 'inherit'
};
if ( cmd === 'help' ) {
	if ( args1._[1] === void 0 ) {
		return help();
	}
	cmd = commands[ args1._[1] ];
	if ( cmd === void 0 ) {
		throw new Error( 'invalid argument. Unrecognized/unsupported command. Value: `' + cmd + '`.' );
	}
	cmd = path.resolve( __dirname, '..', cmd );
	args2 = new Array( 2 );
	args2[ 0 ] = cmd;
	args2[ 1 ] = '--help';
} else {
	if (
		cmd === 'datasets' ||
		cmd === 'ls' ||
		cmd === 'ls-tree' ||
		cmd === 'ns' ||
		cmd === 'repl'
	) {
		cmd = commands[ cmd ];
		cmd = path.resolve( __dirname, '..', cmd );
		args2 = new Array( 1 );
		args2[ 0 ] = cmd;
	}
	else {
		throw new Error( 'invalid argument. Unrecognized/unsupported command. Value: `' + cmd + '`.' );
	}
	for ( i = 1; i < args1._.length; i++ ) {
		args2.push( args1._[ i ] );
	}
}
proc = spawn( 'node', args2, opts );
proc.on( 'error', onError );