pstlab / PLATINUm

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileOutputStream;

import java.io.OutputStreamWriter;

import java.util.Comparator;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.NoSuchElementException;

import java.util.PriorityQueue;

import java.util.Queue;

import java.util.Set;

import org.bson.Document;

import com.mongodb.client.MongoClient;

import com.mongodb.client.MongoClients;

import com.mongodb.client.MongoCollection;

import com.mongodb.client.MongoDatabase;

import it.cnr.istc.pst.platinum.ai.deliberative.solver.SearchSpaceNode;

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

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

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

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

import it.cnr.istc.pst.platinum.ai.framework.domain.knowledge.DomainKnowledge;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.FrameworkObject;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.annotation.inject.framework.PlanDataBasePlaceholder;

import it.cnr.istc.pst.platinum.ai.framework.microkernel.annotation.lifecycle.PostConstruct;

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

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

import it.cnr.istc.pst.platinum.ai.framework.microkernel.resolver.plan.Goal;

import it.cnr.istc.pst.platinum.ai.framework.utils.properties.FilePropertyReader;

/**

 * 

 * @author alessandro

 *

 */

public abstract class SearchStrategy extends FrameworkObject implements Comparator<SearchSpaceNode> {

	@PlanDataBasePlaceholder

	protected PlanDataBase pdb;												// reference to plan data-base

	protected Queue<SearchSpaceNode> fringe;								// the fringe of the search space

	protected String label;													// strategy label

	protected Map<ComponentValue, List<List<ComponentValue>>> pgraph;		// planning graph

	protected Map<DomainComponent, Set<DomainComponent>> dgraph;			// dependency graph

	protected List<DomainComponent>[] dhierarchy;							// domain hierarchy

	protected double schedulingCost;										// set scheduling cost

	protected double completionCost;										// set completion cost

	protected double planningCost;											// general planning cost

	protected double expansionCost;											// detailed planning cost

	protected double unificationCost;										// detailed unification cost

	// set client connection

	protected static MongoClient client;

	// prepare collection

	protected MongoCollection<Document> collection;

	/**

	 * 

	 * @param label

	 */

	protected SearchStrategy(String label) {

		super();

		// initialize the fringe 

		this.fringe = new PriorityQueue<SearchSpaceNode>(this);

		// set label 

		this.label = label;

		// get deliberative property file

		FilePropertyReader properties = new FilePropertyReader(

				FRAMEWORK_HOME + FilePropertyReader.DEFAULT_DELIBERATIVE_PROPERTY);

		// set operation costs from parameters

		this.planningCost = Double.parseDouble(properties.getProperty("expansion-cost"));

		this.expansionCost = Double.parseDouble(properties.getProperty("expansion-cost"));

		this.unificationCost = Double.parseDouble(properties.getProperty("unification-cost"));

		this.schedulingCost = Double.parseDouble(properties.getProperty("scheduling-cost"));

		this.completionCost = Double.parseDouble(properties.getProperty("completion-cost"));

	}

	/**

	 * 

	 */

	@PostConstruct

	protected void init() {

		// get domain knowledge

		DomainKnowledge dk = this.pdb.getDomainKnowledge();

		// get the decomposition tree from the domain theory

		this.pgraph = dk.getDecompositionGraph();

		// export decomposition graph

		this.exportDecompositionGraph(this.pgraph);

		// get dependency graph

		this.dgraph = dk.getDependencyGraph();

		// export dependency graph

		this.exportDependencyGraph(this.dgraph);

		// get domain hierarchy

		this.dhierarchy = dk.getDomainHierarchy();

		// export hierarchy

		this.exportHierarchyGraph(this.dhierarchy);

		// get deliberative property file

		FilePropertyReader properties = new FilePropertyReader(

				FRAMEWORK_HOME + FilePropertyReader.DEFAULT_DELIBERATIVE_PROPERTY);

		// get mongo

		String mongodb = properties.getProperty("mongodb");

		// check if exists

		if (mongodb != null && !mongodb.equals("")) {

			// create a collection to the DB

			if (client == null) {

				// check DB host

				String dbHost = properties.getProperty("mongodb_host");

				// create client

			}

			// get DB 

			MongoDatabase db = client.getDatabase(mongodb.trim());

			// get collection

			this.collection = db.getCollection("planner_search");

			// remove all data from the collection

			this.collection.drop();

		}

	}

	/** 

	 * Compute the (pessimistic) planning cost of a domain value by analyzing the extracted decomposition graph 

	 * 

	 * @param value

	 * @return

	 */

	private Map<DomainComponent, Double[]> computeCostProjections(ComponentValue value) {

		// set cost

		Map<DomainComponent, Double[]> cost = new HashMap<>();

		// check if leaf

		if (!this.pgraph.containsKey(value) || 

				this.pgraph.get(value).isEmpty()) {

			// set cost

			cost.put(value.getComponent(), new Double[] {

					this.unificationCost,

					this.unificationCost

			});

		} else {

			// get possible decompositions

				// decomposition costs

				Map<DomainComponent, Double[]> dCosts = new HashMap<>();

				for (ComponentValue subgoal : decomposition) {

					// compute planning cost of the subgoal

					Map<DomainComponent, Double[]> update = this.computeCostProjections(subgoal);

						if (!dCosts.containsKey(c)) {

							// set cost

							dCosts.put(c, new Double[] {

									update.get(c)[0],

									update.get(c)[1]

							});

						} else {

							// update cost

							dCosts.put(c, new Double[] {

									dCosts.get(c)[0] + update.get(c)[0],

									dCosts.get(c)[1] + update.get(c)[1]

							});

						}

					}

				}

				// update pessimistic and optimistic projections

					if (!cost.containsKey(c)) {

						// set cost

						cost.put(c, new Double[] {

							dCosts.get(c)[0],

							dCosts.get(c)[1]

						});

					} else {

						// get min and max

						cost.put(c, new Double[] {

								Math.min(cost.get(c)[0], dCosts.get(c)[0]),

								Math.max(cost.get(c)[1], dCosts.get(c)[1])

						});

					}

				}

			}

			// set cost associated to the value

			if (!cost.containsKey(value.getComponent())) {

				// set cost

				cost.put(value.getComponent(), new Double[] {

						this.unificationCost,

						this.unificationCost

				});

			} else {

				// weight cost according to the hierarchical value

				cost.put(value.getComponent(), new Double[] {

						this.unificationCost + cost.get(value.getComponent())[0],

						this.unificationCost + cost.get(value.getComponent())[1]

				});

			}

		}

		// get cost

		return cost;

	}

	/**

	 * Compute the (pessimistic) makespan projection by analyzing the extracted decomposition graph starting 

	 * from a given value of the domain

	 * 

	 * @param value

	 * @return

	 */

	private Map<DomainComponent, Double[]> computeMakespanProjections(ComponentValue value)

	{

		// set data structure

		Map<DomainComponent, Double[]> makespan = new HashMap<>();

		// check if leaf

		if (!this.pgraph.containsKey(value) || 

				this.pgraph.get(value).isEmpty()) {

			// set value expected minimum duration

			makespan.put(value.getComponent(), new Double[] {

					(double) value.getDurationLowerBound(),

					(double) value.getDurationUpperBound()

			});

		} else {

			// check possible decompositions

				// set decomposition makespan 

				Map<DomainComponent, Double[]> dMakespan = new HashMap<>();

				// check subgoals

				for (ComponentValue subgoal : decomposition) {

					// recursive call to compute (pessimistic) makespan estimation

					Map<DomainComponent, Double[]> update = this.computeMakespanProjections(subgoal);

					// increment decomposition makespan

						// check decomposition  makespan 

						if (!dMakespan.containsKey(c)) {

							// add entry 

							dMakespan.put(c, new Double[] {

									update.get(c)[0],

									update.get(c)[1]

							});

						} else {

							// increment component's makespan 

							dMakespan.put(c, new Double[] {

									dMakespan.get(c)[0] + update.get(c)[0],

									dMakespan.get(c)[1] + update.get(c)[1]

							});

						}

					}

				}

				// update resulting makespan by taking into account the maximum value

					// check makespan

					if (!makespan.containsKey(c)) {

						// add entry

						makespan.put(c, new Double[] {

								dMakespan.get(c)[0],

								dMakespan.get(c)[1]

						});

					} else {

						// set the pessimistic and optimistic projections

						makespan.put(c, new Double[] {

								Math.min(makespan.get(c)[0], dMakespan.get(c)[0]),

								Math.max(makespan.get(c)[1], dMakespan.get(c)[1])

						});

					}

				}

			}

			// set cost associated to the value

			if (!makespan.containsKey(value.getComponent())) {

				// set cost

				makespan.put(value.getComponent(), new Double[] {

						(double) value.getDurationLowerBound(),

						(double) value.getDurationLowerBound()

				});

			} else {

				// increment makespan

				makespan.put(value.getComponent(), new Double[] {

						makespan.get(value.getComponent())[0] + ((double) value.getDurationLowerBound()),

						makespan.get(value.getComponent())[1] + ((double) value.getDurationLowerBound())

				});

			}

		}

		// get the makespan 

		return makespan;

	}

	/**

	 * 

	 * @return

	 */

	public String getLabel() {

		return this.label;

	}

	/**

	 * 

	 * @return

	 */

	public int getFringeSize() {

		return this.fringe.size();

	}

	/**

	 * 

	 * @param node

	 */

	public abstract void enqueue(SearchSpaceNode node);

	/**

	 * 

	 */

	@Override

	public abstract int compare(SearchSpaceNode n1, SearchSpaceNode n2);

	/**

	 * 

	 * @return

	 * @throws EmptyFringeException

	 */

	public SearchSpaceNode dequeue() 

			throws EmptyFringeException 

	{

		// set next node of the fringe

		SearchSpaceNode next = null;

		try 

		{

			// extract the "best" node from the fringe

			next = this.fringe.remove();

			// store search data record

			this.registerSearchChoice(next);

		}

		catch (NoSuchElementException ex) {

			// empty fringe

			throw new EmptyFringeException("No more nodes in the fringe");

		}

		// get extracted node

		return next;

	}

	/**

	 * Clear the internal data structures of a search strategy

	 */

	public void clear() {

		// clear queue

		this.fringe.clear();

		// close DB connection if necessary 

		if (client != null) {

			client.close();

			this.collection = null;

		}

	}

	/**

	 * 

	 */

	public String toString() {

		// JSON like object description

		return "{ \"label\": \"" + this.label + "\" }";

	}

	/**

	 * 

	 * @param node

	 */

	protected void registerSearchChoice(SearchSpaceNode node) 

	{

		// check db collection

		if (this.collection != null) {

			// create solving statistic record

			Document doc = new Document("step", node.getId());

			doc.append("fringe-size", this.fringe.size());

			doc.append("node-number-of-flaws", node.getNumberOfFlaws());

			doc.append("node-depth", node.getDepth());

			// consolidated values of metrics

			doc.append("node-plan-cost", node.getPlanCost());

			doc.append("node-plan-makespan-min", node.getPlanMakespan()[0]);

			doc.append("node-plan-makespan-max", node.getPlanMakespan()[1]);

			// heuristic estimation of metrics

			doc.append("node-heuristic-plan-cost-min", node.getPlanHeuristicCost()[0]);

			doc.append("node-heuristic-plan-cost-max", node.getPlanHeuristicCost()[1]);

			doc.append("node-heuristic-plan-makespan-min", node.getPlanHeuristicMakespan()[0]);

			doc.append("node-heuristic-plan-makespan-max", node.getPlanHeuristicMakespan()[1]);

			// insert data into the collection

			this.collection.insertOne(doc);

		}

	}

	/**

	 * This method computes an evaluation concerning the (planning) distance of 

	 * a given node from a solution plan. 

	 * 

	 * Namely the method computes the expected cost the planner should "pay" to refine 

	 * the given node and obtain a valid solution. The cost takes into account both planning 

	 * and scheduling decisions. Also, the cost considers possible "gaps" on timelines and 

	 * tries to estimates the planning effort needed to complete the behaviors of 

	 * related timelines.

	 * 

	 * The heuristics computes a cost for each component of the domain and 

	 * takes into account timeline projections and therefore computes a pessimistic 

	 * and optimistic evaluation.

	 * 

	 * @param node

	 * @return

	 */

	/**

	 * 

	 * This method provides an heuristic evaluation of the makespan of domain components.

	 * 

	 * Namely, the method considesrs planning subgoals of a given partial plan and computes 

	 * a projection of the makespan. The evalution takes into account optmistic and pessimistic

	 * projections of timelines

	 * 

	 * @param node

	 * @return

	 */

	protected Map<DomainComponent, Double[]> computeHeuristicMakespan(SearchSpaceNode node)

	{

		// initialize makespan projects

		Map<DomainComponent, Double[]> projections = new HashMap<>();

		// check node flaws and compute heuristic estimation

		for (Flaw flaw : node.getFlaws()) 

		{

			// check planning goals

			if (flaw.getType().equals(FlawType.PLAN_REFINEMENT)) 

			{

				// get planning goal

				Goal goal = (Goal) flaw;

				// compute optimistic and pessimistic projections of makespan from goals

				Map<DomainComponent, Double[]> update = this.computeMakespanProjections(

						goal.getDecision().getValue());

				// update plan projections

				{

					// check projection

					if (!projections.containsKey(c)) {

						// set projection

						projections.put(c, 

							new Double[] {

									update.get(c)[0],

									update.get(c)[1]

							});

					}

					else {

						// update projection

						projections.put(c, 

							new Double[] {

									projections.get(c)[0] + update.get(c)[0],

									projections.get(c)[1] + update.get(c)[1]

							});

					}

				}

			}

		}

		// finalize data structure

		for (DomainComponent c : this.pdb.getComponents()) {

			if (!projections.containsKey(c)) {

				projections.put(c, new Double[] {

						(double) 0, 

						(double) 0

				});

			}

		}

		// get projections

		return projections;

	}

	/**

	 * 

	 * @param graph

	 */

	private void exportHierarchyGraph(List<DomainComponent>[] graph)

	{

		// export graph

		String str = "digraph hierarhcy_graph {\n";

		str += "\trankdir=TB;\n";

		str += "\tnode [fontsize=11, style=filled, fillcolor=azure, shape = box]\n";

		// check dependencies

		for (int index = 0; index < graph.length - 1; index++) {

			// get components at current level

			List<DomainComponent> currlist = graph[index];

			// get components at next level

			List<DomainComponent> nextlist = graph[index + 1];

			for (DomainComponent curr : currlist) {

				for (DomainComponent next : nextlist) {

					// add an edge to the graph

				}

			}

		}

		// close 

		str += "\n}\n\n";

		try 

		{

			File pdlFile = new File(FRAMEWORK_HOME + "hierarchy_graph.dot");

			try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(pdlFile), "UTF-8"))) {

				// write file

				writer.write(str);

			}

		}

		catch (Exception ex) {

		}

	}

	/**

	 * 

	 * @param graph

	 */

	private void exportDependencyGraph(Map<DomainComponent, Set<DomainComponent>> graph)

	{

		// export graph

		String str = "digraph dependency_graph {\n";

		str += "\trankdir=TB;\n";

		str += "\tnode [fontsize=11, style=filled, fillcolor=azure, shape = box]\n";

		// check dependencies

			// check dependencies

			for (DomainComponent dep : graph.get(comp)) {

				// add an edge to the graph

			}

		}

		// close 

		str += "\n}\n\n";

		try 

		{

			File pdlFile = new File(FRAMEWORK_HOME + "dependency_graph.dot");

			try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(pdlFile), "UTF-8"))) {

				// write file

				writer.write(str);

			}

		}

		catch (Exception ex) {

		}

	}

	/**

	 * 

	 * @param graph

	 */

	private void exportDecompositionGraph(Map<ComponentValue, List<List<ComponentValue>>> graph) 

	{

		// export graph

		String str = "digraph decomposition_graph {\n";

		str += "\trankdir=TB;\n";

		str += "\tnode [fontsize=11, style=filled, fillcolor=azure, shape = box]\n";

		// node id

		int counter = 0;

		// create AND nodes

		int andCounter = 0;

		// check the graph

		{

			// check number of disjunctions

			List<List<ComponentValue>> disjunctions = graph.get(value);

			if (disjunctions.size() == 1) 

			{

				String andNode = "AND_" + andCounter;

						" -> " + andNode + ";\n";

				// set weight of the edge

				Map<ComponentValue, Integer> wc = new HashMap<>();

				for (ComponentValue child : disjunctions.get(0)) {

					if (!wc.containsKey(child)) {

						wc.put(child, 1);

					}

					else {

						// increment

						int v = wc.get(child);

						wc.put(child, ++v);

					}

				}

				// no disjunctions

					// add edge

				}

				// increment and node counter

				andCounter++;

			}

			else 

			{

				// add OR node label

				String orLabel = "OR_" + counter;

				// add an edge to the OR node

						" -> " + orLabel + ";\n";

				// add disjunctions

				for (List<ComponentValue> conjunctions : disjunctions) 

				{

					// set AND node label

					String andLabel = "AND_" + andCounter;

					// set weight of the edge

					Map<ComponentValue, Integer> wc = new HashMap<>();

					for (ComponentValue child : conjunctions) {

						if (!wc.containsKey(child)) {

							wc.put(child, 1);

						}

						else {

							// increment

							int v = wc.get(child);

							wc.put(child, ++v);

						}

					}

					// add and edge to the AND node

						// add edge from AND node to the value

								" -> " + child.getComponent().getName() + "_" +child.getLabel().replace("-", "_") + " [label= \"" + wc.get(child) + "\"];\n";

					}

					// increment and node counter

					andCounter++;

				}

				counter++;

			}

		}

		// close 

		str += "\n}\n\n";

		try 

		{

			File pdlFile = new File(FRAMEWORK_HOME + "decomposition_graph.dot");

			try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(pdlFile), "UTF-8"))) {

				// write file

				writer.write(str);

			}

		}

		catch (Exception ex) {

		}

	}

}