Elep

module.exports = function (args, opts) {
    if (!opts) opts = {};

var flags = { bools : {}, strings : {} };

[].concat(opts['boolean']).filter(Boolean).forEach(function (key) {
        flags.bools[key] = true;
    });

[].concat(opts.string).filter(Boolean).forEach(function (key) {
        flags.strings[key] = true;
    });

var defaults = opts['default'] || {};

var argv = { _ : [] };
    Object.keys(flags.bools).forEach(function (key) {
        setArg(key, defaults[key] === undefined ? false : defaults[key]);
    });

var notFlags = [];

if (args.indexOf('--') !== -1) {
        notFlags = args.slice(args.indexOf('--')+1);
        args = args.slice(0, args.indexOf('--'));
    }

function setArg (key, val) {
        var value = !flags.strings[key] && isNumber(val)
            ? Number(val) : val
        ;
        setKey(argv, key.split('.'), value);

(aliases[key] || []).forEach(function (x) {
            setKey(argv, x.split('.'), value);
        });
    }

for (var i = 0; i < args.length; i++) {
        var arg = args[i];

if (/^--.+=/.test(arg)) {
            // Using [\s\S] instead of . because js doesn't support the
            // 'dotall' regex modifier. See:
            // http://stackoverflow.com/a/1068308/13216
            var m = arg.match(/^--([^=]+)=([\s\S]*)$/);
            setArg(m[1], m[2]);
        }
        else if (/^--no-.+/.test(arg)) {
            var key = arg.match(/^--no-(.+)/)[1];
            setArg(key, false);
        }
        else if (/^--.+/.test(arg)) {
            var key = arg.match(/^--(.+)/)[1];
            var next = args[i + 1];
            if (next !== undefined && !/^-/.test(next)
            && !flags.bools[key]
            && (aliases[key] ? !flags.bools[aliases[key]] : true)) {
                setArg(key, next);
                i++;
            }
            else if (/^(true|false)$/.test(next)) {
                setArg(key, next === 'true');
                i++;
            }
            else {
                setArg(key, flags.strings[key] ? '' : true);
            }
        }
        else if (/^-[^-]+/.test(arg)) {
            var letters = arg.slice(1,-1).split('');

var broken = false;
            for (var j = 0; j < letters.length; j++) {
                var next = arg.slice(j+2);

if (next === '-') {
                    setArg(letters[j], next)
                    continue;
                }

if (/[A-Za-z]/.test(letters[j])
                && /-?\d+(\.\d*)?(e-?\d+)?$/.test(next)) {
                    setArg(letters[j], next);
                    broken = true;
                    break;
                }

if (letters[j+1] && letters[j+1].match(/\W/)) {
                    setArg(letters[j], arg.slice(j+2));
                    broken = true;
                    break;
                }
                else {
                    setArg(letters[j], flags.strings[letters[j]] ? '' : true);
                }
            }

Object.keys(defaults).forEach(function (key) {
        if (!hasKey(argv, key.split('.'))) {
            setKey(argv, key.split('.'), defaults[key]);

(aliases[key] || []).forEach(function (x) {
                setKey(argv, x.split('.'), defaults[key]);
            });
        }
    });

notFlags.forEach(function(key) {
        argv._.push(key);
    });

return argv;
};

function hasKey (obj, keys) {
    var o = obj;
    keys.slice(0,-1).forEach(function (key) {
        o = (o[key] || {});
    });

var key = keys[keys.length - 1];
    return key in o;
}

function setKey (obj, keys, value) {
    var o = obj;
    keys.slice(0,-1).forEach(function (key) {
        if (o[key] === undefined) o[key] = {};
        o = o[key];
    });

function isNumber (x) {
    if (typeof x === 'number') return true;
    if (/^0x[0-9a-f]+$/i.test(x)) return true;
    return /^[-+]?(?:\d+(?:\.\d*)?|\.\d+)(e[-+]?\d+)?$/.test(x);
}

function longest (xs) {
    return Math.max.apply(null, xs.map(function (x) { return x.length }));
}