public bool buildtree(joshstatetree start, List <joshstatetree> tree, HashSet <joshgoapaction> usableactionset, HashSet <KeyValuePair <string, object> > goal)
{
bool pathfound = false;
foreach (joshgoapaction item in usableactionset)
{
bool temp = containsstate(start.worldstate, item.preconditions, false);//item.target!=null&&start.parent==null);
//Debug.Log(item+" "+temp);
if (temp)
{
HashSet <KeyValuePair <string, object> > alteredState = applystate(start.worldstate, item.effects);
joshstatetree node = new joshstatetree(start, start.totalcost + item.basecost, alteredState, item);
if (containsstate(alteredState, goal, false))
{
tree.Add(node);
pathfound = true;
}
else
{
// recursively look through states below this one
// todo figure out the logic behind stopping an action from being run several times
HashSet <joshgoapaction> subset = actionSubset(usableactionset, item);
//subset.Remove(item);
bool found = buildtree(node, tree, subset, goal);
if (found)
{
pathfound = true;
}
}
}
}
return(pathfound);
}
public joshstatetree(joshstatetree root, float total, HashSet <KeyValuePair <string, object> > state, joshgoapaction act)
{
parent = root;
totalcost = total;
worldstate = state;
action = act;
}
public Queue <joshgoapaction> MakePlan(HashSet <joshgoapaction> availableActions, HashSet <KeyValuePair <string, object> > goal, HashSet <KeyValuePair <string, object> > worldstate)
{
HashSet <joshgoapaction> usableactions = new HashSet <joshgoapaction>();
foreach (joshgoapaction item in availableActions)
{
if (item.CheckPreconditions())
{
usableactions.Add(item);
}
}
List <joshstatetree> validpaths = new List <joshstatetree>();
joshstatetree start = new joshstatetree(null, 0, worldstate, null);
bool succeeded = buildtree(start, validpaths, usableactions, goal);
if (!succeeded)
{
Debug.Log("no valid plan found to goal");
return(null);
}
// get the cheapest path
joshstatetree cheapest = null;
foreach (joshstatetree path in validpaths)
{
//Debug.Log(path.action);
//Debug.Log(path.parent.action);
//Debug.Log(path.parent.parent?.action);
//Debug.Log(path.parent.action);
if (cheapest == null)
{
cheapest = path;
}
else
{
if (path.totalcost < cheapest.totalcost)
{
cheapest = path;
}
}
}
// get a finished path and go back through it's parents
List <joshgoapaction> result = new List <joshgoapaction> ();
joshstatetree n = cheapest;
while (n != null)
{
//Debug.Log(n.action);
if (n.action != null)
{
result.Insert(0, n.action); // insert the action in the front
}
n = n.parent;
}
Queue <joshgoapaction> queue = new Queue <joshgoapaction> ();
foreach (joshgoapaction a in result)
{
//Debug.Log(a);
queue.Enqueue(a);
}
// hooray we have a plan!
return(queue);
}
