/// <summary>
/// Filters candidates for substeps, at least one with height "height"
/// </summary>
/// <param name="decomp"></param>
/// <returns> List of decompositions with ground sub-steps. </returns>
public static List <Decomposition> FilterDecompCandidates(Decomposition decomp, int height)
{
// find and replace sub-steps
var comboList = new List <List <IOperator> >();
var ID_List = new List <int>();
foreach (var substep in decomp.SubSteps)
{
ID_List.Add(substep.ID);
// each substep has ground terms that are already consistent. Composite IS-A Operator
var cndts = ConsistentSteps(substep.Action as Operator);
// If there's no cndts for this substep, then abandon this decomp.
if (cndts.Count == 0)
{
return(new List <Decomposition>());
}
comboList.Add(cndts);
}
List <Decomposition> decompList = new List <Decomposition>();
foreach (var combination in EnumerableExtension.GenerateCombinations(comboList))
{
var decompClone = decomp.Clone() as Decomposition;
var newSubsteps = new List <IPlanStep>();
var substepDict = new Dictionary <int, IPlanStep>();
var order = 0;
var hasPrerequisiteHeight = false;
foreach (var item in combination)
{
if (item.Height >= height)
{
// meets height requirement
hasPrerequisiteHeight = true;
}
var originalID = ID_List[order++];
if (item.Height > 0)
{
var newPlanStep = new CompositePlanStep(item as Composite);
substepDict[originalID] = newPlanStep;
newSubsteps.Add(newPlanStep);
}
else
{
var newPlanStep = new PlanStep(item);
substepDict[originalID] = newPlanStep;
newSubsteps.Add(newPlanStep);
}
}
// Did not meet requirements for height.
if (!hasPrerequisiteHeight)
{
continue;
}
var newSuborderings = new List <Tuple <IPlanStep, IPlanStep> >();
foreach (var subordering in decomp.SubOrderings)
{
var first = substepDict[subordering.First.ID];
var second = substepDict[subordering.Second.ID];
newSuborderings.Add(new Tuple <IPlanStep, IPlanStep>(first, second));
}
var linkWorlds = new List <List <CausalLink <IPlanStep> > >();
linkWorlds.Add(new List <CausalLink <IPlanStep> >());
var newSublinks = new List <CausalLink <IPlanStep> >();
foreach (var sublink in decomp.SubLinks)
{
var head = substepDict[sublink.Head.ID];
var tail = substepDict[sublink.Tail.ID];
var cndts = head.Effects.Where(eff => eff.IsConsistent(sublink.Predicate) && tail.Preconditions.Any(pre => pre.Equals(eff)));
if (cndts.Count() == 0)
{
// forfeit this entire subplan
linkWorlds = new List <List <CausalLink <IPlanStep> > >();
continue;
}
if (cndts.Count() == 1)
{
var cndt = cndts.First();
var dependency = cndt.Clone() as Predicate;
var newLink = new CausalLink <IPlanStep>(dependency, head, tail);
newLink.Tail.Fulfill(cndt);
foreach (var linkworld in linkWorlds)
{
linkworld.Add(newLink);
}
}
else
{
foreach (var cndt in cndts)
{
var dependency = cndt.Clone() as Predicate;
var newLink = new CausalLink <IPlanStep>(dependency, head, tail);
newLink.Tail.Fulfill(cndt);
var clonedLinks = EnumerableExtension.CloneList(newSublinks);
linkWorlds.Add(clonedLinks);
foreach (var linkworld in linkWorlds)
{
linkworld.Add(newLink);
}
}
}
}
foreach (var linkworld in linkWorlds)
{
var newDecomp = decomp.Clone() as Decomposition;
newDecomp.SubSteps = newSubsteps;
newDecomp.SubOrderings = newSuborderings;
newDecomp.SubLinks = linkworld;
decompList.Add(newDecomp);
}
}
return(decompList);
}
