const _ = require( 'lodash' );

const optionDefine = {
    help: {
        type: 'boolean',
        alias: 'h',
        default: false,
        description: 'display this help'
    },
    list: {
        type: 'boolean',
        alias: 'l',
        default: false,
        description: 'display tasks'
    },
    silent: {
        type: 'boolean',
        default: false,
        description: 'log errors only'
    },
    debug: {
        type: 'boolean',
        default: false,
        description: ''
    },
    version: {
        type: 'boolean',
        alias: 'v',
        default: false,
        description: 'display version'
    }
};

optionDefine[Symbol.iterator] = function* () {
    for ( let key in this ) {
        yield [ key, this[key] ];
    }
};

function showHelp(aOptionDefine) {
    const maxLength = _
          .chain( _.keys( optionDefine ) )
          .map( name => name.length )
          .max()
          .value();

    console.log( 'Options:' );
    for ( let  [name, opts] of aOptionDefine ) {
        process.stdout.write( '  ' );

        if ( opts.alias === undefined ) {
            process.stdout.write( '   ' );
        } else {
            process.stdout.write( `-${opts.alias},` );
        }

        process.stdout.write( ` --${name}` );
        process.stdout.write( _.repeat( ' ', ( maxLength - name.length ) + 2 ) );
        process.stdout.write( opts.description );
        process.stdout.write( '\n' );
    }
}


showHelp( optionDefine );