module.exports = function (args, opts) {
if (!opts) opts = {};
var flags = { bools : {}, strings : {}, unknownFn: null };
if (typeof opts['unknown'] === 'function') {
flags.unknownFn = opts['unknown'];
}
if (typeof opts['boolean'] === 'boolean' && opts['boolean']) {
flags.allBools = true;
} else {
[].concat(opts['boolean']).filter(Boolean).forEach(function (key) {
flags.bools[key] = true;
});
}
var aliases = {};
Object.keys(opts.alias || {}).forEach(function (key) {
aliases[key] = [].concat(opts.alias[key]);
aliases[key].forEach(function (x) {
aliases[x] = [key].concat(aliases[key].filter(function (y) {
return x !== y;
}));
});
});
[].concat(opts.string).filter(Boolean).forEach(function (key) {
flags.strings[key] = true;
if (aliases[key]) {
flags.strings[aliases[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 argDefined(key, arg) {
return (flags.allBools && /^--[^=]+$/.test(arg)) ||
flags.strings[key] || flags.bools[key] || aliases[key];
}
function setArg (key, val, arg) {
if (arg && flags.unknownFn && !argDefined(key, arg)) {
if (flags.unknownFn(arg) === false) return;
}
var value = !flags.strings[key] && isNumber(val)
? Number(val) : val
;
setKey(argv, key.split('.'), value);
(aliases[key] || []).forEach(function (x) {
setKey(argv, x.split('.'), value);
});
}
function setKey (obj, keys, value) {
var o = obj;
keys.slice(0,-1).forEach(function (key) {
if (o[key] === undefined) o[key] = {};
o = o[key];
});
var key = keys[keys.length - 1];
if (o[key] === undefined || flags.bools[key] || typeof o[key] === 'boolean') {
o[key] = value;
}
else if (Array.isArray(o[key])) {
o[key].push(value);
}
else {
o[key] = [ o[key], value ];
}
}
function aliasIsBoolean(key) {
return aliases[key].some(function (x) {
return flags.bools[x];
});
}
for (var i = 0; i < args.length; i++) {
var arg = args[i];
if (/^--.+=/.test(arg)) {
// Using [\s\S] instead of . because js doesn't support the
// 'dotall' regex modifier. See:
// http://stackoverflow.com/a/1068308/13216
var m = arg.match(/^--([^=]+)=([\s\S]*)$/);
var key = m[1];
var value = m[2];
if (flags.bools[key]) {
value = value !== 'false';
}
setArg(key, value, arg);
}
else if (/^--no-.+/.test(arg)) {
var key = arg.match(/^--no-(.+)/)[1];
setArg(key, false, arg);
}
else if (/^--.+/.test(arg)) {
var key = arg.match(/^--(.+)/)[1];
var next = args[i + 1];
if (next !== undefined && !/^-/.test(next)
&& !flags.bools[key]
&& !flags.allBools
&& (aliases[key] ? !aliasIsBoolean(key) : true)) {
setArg(key, next, arg);
i++;
}
else if (/^(true|false)$/.test(next)) {
setArg(key, next === 'true', arg);
i++;
}
else {
setArg(key, flags.strings[key] ? '' : true, arg);
}
}
else if (/^-[^-]+/.test(arg)) {
var letters = arg.slice(1,-1).split('');
var broken = false;
for (var j = 0; j < letters.length; j++) {
var next = arg.slice(j+2);
if (next === '-') {
setArg(letters[j], next, arg)
continue;
}
if (/[A-Za-z]/.test(letters[j]) && /=/.test(next)) {
setArg(letters[j], next.split('=')[1], arg);
broken = true;
break;
}
if (/[A-Za-z]/.test(letters[j])
&& /-?\d+(\.\d*)?(e-?\d+)?$/.test(next)) {
setArg(letters[j], next, arg);
broken = true;
break;
}
if (letters[j+1] && letters[j+1].match(/\W/)) {
setArg(letters[j], arg.slice(j+2), arg);
broken = true;
break;
}
else {
setArg(letters[j], flags.strings[letters[j]] ? '' : true, arg);
}
}
var key = arg.slice(-1)[0];
if (!broken && key !== '-') {
if (args[i+1] && !/^(-|--)[^-]/.test(args[i+1])
&& !flags.bools[key]
&& (aliases[key] ? !aliasIsBoolean(key) : true)) {
setArg(key, args[i+1], arg);
i++;
}
else if (args[i+1] && /true|false/.test(args[i+1])) {
setArg(key, args[i+1] === 'true', arg);
i++;
}
else {
setArg(key, flags.strings[key] ? '' : true, arg);
}
}
}
else {
if (!flags.unknownFn || flags.unknownFn(arg) !== false) {
argv._.push(
flags.strings['_'] || !isNumber(arg) ? arg : Number(arg)
);
}
if (opts.stopEarly) {
argv._.push.apply(argv._, args.slice(i + 1));
break;
}
}
}
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]);
});
}
});
if (opts['--']) {
argv['--'] = new Array();
notFlags.forEach(function(key) {
argv['--'].push(key);
});
}
else {
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 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);
}