pstlab / PLATINUm

import java.util.ArrayList;

import java.util.List;

import it.cnr.istc.pst.platinum.ai.deliberative.heuristic.pipeline.PipelineFlawSelectionHeuristic;

import it.cnr.istc.pst.platinum.ai.deliberative.strategy.CostDepthSearchStrategy;

import it.cnr.istc.pst.platinum.ai.deliberative.strategy.ex.EmptyFringeException;

import it.cnr.istc.pst.platinum.ai.framework.domain.component.PlanElementStatus;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.annotation.cfg.deliberative.FlawSelectionHeuristicsConfiguration;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.annotation.cfg.deliberative.SearchStrategyConfiguration;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.lang.ex.ConsistencyCheckException;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.lang.ex.NoFlawFoundException;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.lang.ex.NoSolutionFoundException;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.lang.ex.PlanRefinementException;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.lang.flaw.Flaw;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.resolver.ex.UnsolvableFlawException;

/**

 * 

 * @author anacleto

 *

 */

@FlawSelectionHeuristicsConfiguration(

		heuristics = PipelineFlawSelectionHeuristic.class

)

@SearchStrategyConfiguration(

		strategy = CostDepthSearchStrategy.class

)

public class PseudoControllabilityAwareSolver extends Solver 

{

	/**

	 * 

	 * @param timeout

	 */

	protected PseudoControllabilityAwareSolver(long timeout) {

		super("PseudoControllabilityAwareSolver", timeout);

	}

	/**

	 * 

	 */

	@Override

	public SearchSpaceNode solve() 

			throws NoSolutionFoundException 

	{

		// set solving start time

		long start = System.currentTimeMillis();

		// set solving step counter

		this.stepCounter = 0;

		// last extracted node

		SearchSpaceNode last = null, node = null;

		// search condition

		boolean search = true;

		// search a solution

		while (search) 

		{

			try 

			{

				// update step counter

				this.stepCounter++;

				// get time passed from the start 

				long now = System.currentTimeMillis() - start;

				// check timeout

				if (this.timeout > 0 && now > this.timeout) 

				{

					// no solution found stop search

					search = false;

					// set solving time

					this.time = System.currentTimeMillis() - start;

					// backtrack from the last propagated node

					this.backtrack(last);

					// timeout exception

					throw new NoSolutionFoundException("Timeout: no solution found after " + this.time + " msecs and " + this.stepCounter + " solving steps");

				}

				// extract a node from the fringe

				node = this.fringe.dequeue();

				// info message

				String info = "Extracted node [step = " + this.stepCounter + "]:\n"

						+ "node: " + node + "\n";

				// check operators 

				if (last != null) {

					// print last node operations

					for (Operator op : node.getOperators()) {

					}

				}

				// info log 

				info(info);

				// propagate extracted node

				this.contextSwitch(last, node);

				// updated last propagated node

				last = node;

				// check consistency of the resulting partial plan

				this.pdb.verify();

				// context switch done

				info("Context switch successfully done [step = " + this.stepCounter + "]:\n"

						+ "Plan: " + last.getPartialPlan() + "\n");

				// print information concerning current partial plan	

				debug("Detailed plan after propagation: "  + node.getGenerator() + "\n"

							+ "\tplan:\n"

							+ "\t\tdecisions= " + this.pdb.getPlan().getDecisions() + "\n"

							+ "\t\trelations= " + this.pdb.getPlan().getRelations() + "\n\n"

							+ "\tpending plan (agenda):\n"

							+ "\t\tdecisions= " + this.pdb.getPlan(PlanElementStatus.PENDING).getDecisions() + "\n"

							+ "\t\trelations= " + this.pdb.getPlan(PlanElementStatus.PENDING).getRelations() + "\n\n"

							+ "\tsilent plan:\n"

							+ "\t\tdecisions= " + this.pdb.getPlan(PlanElementStatus.SILENT).getDecisions() + "\n"

							+ "\t\trelations= " + this.pdb.getPlan(PlanElementStatus.SILENT).getRelations() + "\n\n");

 				// choose the best flaws to solve

				List<Flaw> flaws = new ArrayList<>(this.heuristic.choose());

				// create a branch for each "equivalent" flaw to solve next

				for (Flaw flaw : flaws)

				{

					// expand the search space with the available solutions of the flaw

					for (SearchSpaceNode child : this.expand(node, flaw)) {

						// add the node to the fringe

						this.fringe.enqueue(child);

						// expand the search space

						info("Search tree expansion:\n"

								+ "node: " + child + "\n"

								+ "generator: " + child.getGenerator() + "\n");

					}

				}

			}

			catch (PlanRefinementException ex) {

				// refinement error

				warning("Refinement error [step = " + this.stepCounter + "]:\n"

						+ "message: " + ex.getMessage() + "\n"

						+ "Plan:\n" + last.getPartialPlan() + "\n");

			}

			catch (UnsolvableFlawException ex) {

				// refinement error

				warning("Unsolvable flaw found  [step = " + this.stepCounter + "]:\n"

						+ "message: " + ex.getMessage() + "\n"

						+ "Plan:\n" + last.getPartialPlan() + "\n");

			}

			catch (ConsistencyCheckException ex) 

			{

				// context switch failure

				warning("Context switch failure [step = " + this.stepCounter + "]:\n"

						+ "message: " + ex.getMessage() + "\n"

						+ "Plan:\n" + last.getPartialPlan() + "\n");

			}

			catch (NoFlawFoundException ex)

			{

				// solution found stop search

				search = false;

				// set solving time

				this.time = System.currentTimeMillis() - start;

				// pseudo-controllable solution found

				info("Pseudo-controllable solution found after " + (this.time / 1000) + " (secs) and " + this.stepCounter + " solving steps\n");

			}

			catch (EmptyFringeException ex) 

			{

				// no solution found stop search

				search = false;

				// set solving time

				this.time = System.currentTimeMillis() - start;

				// backtrack from the last propagated node

				this.backtrack(last);

				// throw exception

				throw new NoSolutionFoundException("No pseudo-controllable solution found after " + (this.time / 1000) + " (secs) and " + this.stepCounter + " solving steps\n");

			}

			// close connection

			finally 

			{

				// check if stop

				if (!search)  {

					// clear data structures

					this.clear();

				}

			}

		} // end while

		// get last expanded node

		return last;

	}

	/**

	 * 

	 */

}