internal void UndoPackageComposition()
{
var rulesThatISuperceed = InstalledPackageFeed.Instance.FindPackages(CanonicalName.AllPackages)
.Except(this.SingleItemAsEnumerable())
.OrderBy(each => each, new Toolkit.Extensions.Comparer <Package>((packageA, packageB) => GeneralPackageSettings.Instance.WhoWins(packageA, packageB)))
.Where(WinsVersus)
.SelectMany(package => package.ResolvedRules.Select(rule => new { package, rule }))
.WhereDistinct(each => each.rule.Destination)
.ToArray();
var rulesThatSuperceedMine = InstalledPackageFeed.Instance.FindPackages(CanonicalName.AllPackages).Where(package => !WinsVersus(package)).SelectMany(package => package.ResolvedRules).ToArray();
foreach (var rule in ResolvedRules)
{
// there are three possibilities
if (rule.Action == CompositionAction.DownloadFile || rule.Action == CompositionAction.InstallCommand)
{
//skip these types of rules.
continue;
}
// never supercede RemoveCommand.
if (rule.Action != CompositionAction.RemoveCommand)
{
// 1. my rule was already superceded by another rule: do nothing.
if (rulesThatSuperceedMine.Any(each => each.Destination.Equals(rule.Destination, StringComparison.CurrentCultureIgnoreCase)))
{
continue;
}
// 2. my rule was superceding another: run that rule.
var runRule = rulesThatISuperceed.FirstOrDefault(each => each.rule.Destination.Equals(rule.Destination, StringComparison.CurrentCultureIgnoreCase));
if (runRule != null)
{
runRule.package.ApplyRule(runRule.rule);
continue;
}
}
// 3. my rule should be the current rule, let's undo it.
switch (rule.Action)
{
case CompositionAction.Shortcut:
if (ShellLink.PointsTo(rule.Destination, rule.Source))
{
rule.Destination.TryHardToDelete();
}
break;
case CompositionAction.SymlinkFile:
if (File.Exists(rule.Destination) && Symlink.IsSymlink(rule.Destination) && Symlink.GetActualPath(rule.Destination).Equals(rule.Source))
{
Symlink.DeleteSymlink(rule.Destination);
}
break;
case CompositionAction.SymlinkFolder:
if (Symlink.IsSymlink(rule.Destination) && Symlink.GetActualPath(rule.Destination).Equals(rule.Source))
{
Symlink.DeleteSymlink(rule.Destination);
}
break;
case CompositionAction.Registry:
if (CanonicalName.Architecture == Architecture.x64 && Environment.Is64BitOperatingSystem)
{
RegistryView.System["SOFTWARE"][rule.Key].StringValue = null;
}
else
{
RegistryView.System["SOFTWARE\\Wow6432Node"][rule.Key].StringValue = null;
}
break;
case CompositionAction.EnvironmentVariable:
// not implemented yet.
break;
case CompositionAction.RemoveCommand:
ExecuteCommand(rule.Source, rule.Destination);
break;
}
}
}