// Get information about MSI-installed products that match a specified product name regex.
// If no products match, or no regex is specified, set errorlevel 1.
//
// An older version of this script would list all MSI-installed products if no regex was
// supplied. Given that the motivation for this script was to help with software deletion,
// this proved dangerous when the match regex was a computed value. To match all products
// with this version, use an explicit . regex.
//
// Stephen Thomas <flabdablet@fastmail.fm>
// Last updated 19-Jun-2015
//
// This is free software. Do whatever you like with it except
// hold me accountable for any grief it causes you.



// Getting at the registry from jscript requires bizarre contortions: see
// http://msdn.microsoft.com/en-us/library/aa392722
// http://msdn.microsoft.com/en-us/library/aa389294
// http://msdn.microsoft.com/en-us/library/aa392730
// http://msdn.microsoft.com/en-us/library/aa394616

reg = (function() {
	var registry = GetObject('winmgmts:{impersonationLevel=impersonate}!root/default:StdRegProv');
	return {
		HKCR: 0x80000000,
		HKCU: 0x80000001,
		HKLM: 0x80000002,
		HKU:  0x80000003,
		HKCC: 0x80000005,

		enumKey: function (hive, key) {
			var method = registry.Methods_.Item('EnumKey');
			var inParam = method.InParameters.SpawnInstance_();
			inParam.hDefKey = hive;
			inParam.sSubKeyName = key;
			var outParam = registry.ExecMethod_(method.Name, inParam);
			if (outParam.ReturnValue == 0) {
				return outParam.sNames.toArray();
			}
			else return [];
		},

		getStringValue: function (hive, key, name) {
			var method = registry.Methods_.Item('GetStringValue');
			var inParam = method.InParameters.SpawnInstance_();
			inParam.hDefKey = hive;
			inParam.sSubKeyName = key;
			inParam.sValueName = name;
			var outParam = registry.ExecMethod_(method.Name, inParam);
			if (outParam.ReturnValue == 0) {
				return outParam.sValue;
			}
			else return null;
		}
	}
})();



// Squished GUIDs are extremely little-endian (low nybble first) hex dumps of raw GUID structs: see
// http://support.microsoft.com/kb/976220
// http://msdn.microsoft.com/en-us/library/windows/desktop/aa373931
// http://www.symantec.com/connect/articles/brief-note-installer-guids

function unsquish(squishedGuid) {
	return '{76543210-BA98-FEDC-HGJI-LKNMPORQTSVU}'.replace(/[0-Z]/g, function(d) {
		return squishedGuid.charAt(parseInt(d, 36));
	});
}



// Main

productsKey = 'SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Installer\\UserData\\S-1-5-18\\Products';
results = [];

if (WScript.Arguments.length) {
	filter = new RegExp(WScript.Arguments(0), 'i');
	products = reg.enumKey(reg.HKLM, productsKey);
	for (i = 0; i < products.length; ++i) {
		installPropertiesKey = productsKey + '\\' + products[i] + '\\InstallProperties';
		name = reg.getStringValue(reg.HKLM, installPropertiesKey, 'DisplayName');
		if (filter.test(name)) {
			package = reg.getStringValue(reg.HKLM, installPropertiesKey, 'LocalPackage');
			results.push([products[i], unsquish(products[i]), package, name].join('\t'));
		}
	}
}

if (results.length) {
	WScript.Echo(results.join('\r\n'));
} else {
	WScript.Quit(1);
}