/// <summary>
/// Tries to fulfill the specified <paramref name="demand"/>. Adds the result to <see cref="Selections"/> if successful.
/// </summary>
/// <returns><c>true</c> if the demand could be met, <c>false</c> if not.</returns>
protected bool TryFulfill(SolverDemand demand)
{
var candidates = GetCompatibleCandidates(demand);
var existingSelection = Selections.GetImplementation(demand.Requirements.InterfaceUri);
if (existingSelection == null)
{ // Try to make new selection
return(TryFulfill(demand, candidates));
}
else
{ // Try to use existing selection
// Ensure existing selection is one of the compatible candidates
if (candidates.All(x => x.Implementation.ID != existingSelection.ID))
{
return(false);
}
if (!existingSelection.ContainsCommand(demand.Requirements.Command ?? Command.NameRun))
{ // Add additional command to selection if needed
var command = existingSelection.AddCommand(demand.Requirements, from: CandidateProvider.LookupOriginalImplementation(existingSelection));
return((command == null) || TryFulfill(DemandsFor(command, demand.Requirements.InterfaceUri)));
}
return(true);
}
}
/// <summary>
/// Shows a list of changes found by the update process.
/// </summary>
protected override ExitCode ShowOutput()
{
var builder = new StringBuilder();
foreach (var oldImplementation in _oldSelections.Implementations)
{
var interfaceUri = oldImplementation.InterfaceUri;
var newImplementation = Selections.GetImplementation(interfaceUri);
if (newImplementation == null)
{ // Implementation removed
builder.AppendLine(Resources.NoLongerUsed + interfaceUri);
}
else if (oldImplementation.Version != newImplementation.Version)
{ // Implementation updated
builder.AppendLine(interfaceUri + ": " + oldImplementation.Version + " -> " + newImplementation.Version);
}
}
foreach (var newImplementation in Selections.Implementations)
{
var interfaceUri = newImplementation.InterfaceUri;
if (!_oldSelections.ContainsImplementation(interfaceUri))
{ // Implementation added
builder.AppendLine(interfaceUri + ": new -> " + newImplementation.Version);
}
}
// Detect replaced feeds
try
{
var feed = FeedCache.GetFeed(Requirements.InterfaceUri);
if (feed.ReplacedBy != null)
{
builder.AppendLine(string.Format(Resources.FeedReplaced, Requirements.InterfaceUri, feed.ReplacedBy.Target));
}
}
catch (KeyNotFoundException)
{
}
if (builder.Length == 0)
{
Handler.OutputLow(Resources.NoUpdatesFound, Resources.NoUpdatesFound);
return(ExitCode.NoChanges);
}
else
{
Handler.Output(Resources.ChangesFound, builder.ToString());
return(ExitCode.OK);
}
}
private static void ApplyVersionRestrictions(Requirements requirements, Selections selections)
{
if (requirements.ExtraRestrictions.Count == 0)
{
return;
}
// TODO
Log.Warn($"You have applied a version restriction to this app. Zero Install will continue to apply this restriction to any future updates. You will need to run '0install select --customize {requirements.InterfaceUri}' to undo this.");
foreach (var restriction in requirements.ExtraRestrictions)
{
var selection = selections.GetImplementation(restriction.Key);
if (selection != null)
{
var pref = FeedPreferences.LoadForSafe(restriction.Key);
pref.Implementations.Clear();
pref[selection.ID].UserStability = Stability.Preferred;
pref.SaveFor(restriction.Key);
}
}
}
/// <inheritdoc/>
public IEnumerable <SelectionsDiffNode> GetDiff(Selections oldSelections, Selections newSelections)
{
#region Sanity checks
if (oldSelections == null)
{
throw new ArgumentNullException(nameof(oldSelections));
}
if (newSelections == null)
{
throw new ArgumentNullException(nameof(newSelections));
}
#endregion
foreach (var newImplementation in newSelections.Implementations)
{
var interfaceUri = newImplementation.InterfaceUri;
if (!oldSelections.ContainsImplementation(interfaceUri))
{ // Implementation added
yield return(new(interfaceUri, newVersion : newImplementation.Version));
}
}
foreach (var oldImplementation in oldSelections.Implementations)
{
var interfaceUri = oldImplementation.InterfaceUri;
var newImplementation = newSelections.GetImplementation(interfaceUri);
if (newImplementation == null)
{ // Implementation removed
yield return(new(interfaceUri, oldVersion : oldImplementation.Version));
}
else if (oldImplementation.Version != newImplementation.Version)
{ // Implementation updated
yield return(new(interfaceUri, oldVersion : oldImplementation.Version, newVersion : newImplementation.Version));
}
}
}
private static void ApplyVersionRestrictions(Requirements requirements, Selections selections)
{
if (requirements.ExtraRestrictions.Count == 0) return;
// TODO
Log.Warn(string.Format("You have applied a version restriction to this app. Zero Install will continue to apply this restriction to any future updates. You will need to run '0install select --customize {0}' to undo this.", requirements.InterfaceUri));
foreach (var restriction in requirements.ExtraRestrictions)
{
var selection = selections.GetImplementation(restriction.Key);
if (selection != null)
{
var pref = FeedPreferences.LoadForSafe(restriction.Key);
pref.Implementations.Clear();
pref[selection.ID].UserStability = Stability.Preferred;
pref.SaveFor(restriction.Key);
}
}
}