pstlab / PLATINUm

import java.util.ArrayList;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

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.DomainComponentType;

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

/**

 * 

 * @author alessandro

 *

 */

	protected List<StateVariableValue> values;							

	// SV's transition function

	protected Map<StateVariableValue, Map<StateVariableValue, Transition>> transitions;

	protected Map<StateVariableValue, Map<StateVariableValue, Transition>> inverseTransitions;

	/**

	 * 

	 * @param name

	 * @param type

	 */

	protected StateVariable(String name, DomainComponentType type) {

		super(name, type);

		// initialize the list of values

		this.values = new ArrayList<StateVariableValue>();

		// initialize transition function

		this.transitions = new HashMap<>();

		// initialize transition function

		this.inverseTransitions = new HashMap<>();

	}

	/**

	 * 

	 * @param label

	 * @param duration

	 * @param controllable

	 * @return

	 */

	public StateVariableValue addStateVariableValue(String label, long[] duration, boolean controllable) {

		// create and add value

		StateVariableValue value = new StateVariableValue(label, duration, controllable, this);

		// add to available values

		this.values.add(value);

		// initialize transition data structure

		this.transitions.put(value, new HashMap<>());

		// initialize inverse transition data structure

		this.inverseTransitions.put(value, new HashMap<>());

		// get value

		return value;

	}

	/**

	 * State variable values without duration bounds are implicitly treated as controllable

	 * 

	 * @param label

	 * @return

	 */

	public StateVariableValue addStateVariableValue(String label) {

		return this.addStateVariableValue(label, new long [] {1l, this.tdb.getHorizon()}, true);

	}

	/**

	 * 

	 * @param reference

	 * @param target

	 * @return

	 */

	public Transition addValueTransition(StateVariableValue reference, StateVariableValue target) {

		// check values

		if (!this.values.contains(reference) || !this.values.contains(target)) {

		}

		// create transition

		Transition t = new Transition(reference, target);

		// check transition

		if (!this.transitions.containsKey(reference)) {

			this.transitions.put(reference, new HashMap<>());

		}

		// add transition

		this.transitions.get(reference).put(target, t);

		// check inverse transition

		if (!this.inverseTransitions.containsKey(target) ) {

			this.inverseTransitions.put(target, new HashMap<>());

		}

		// add inverse transition

		this.inverseTransitions.get(target).put(reference, t);

		// get transition

		return t;

	}

	/**

	 * 

	 * @param reference

	 * @param target

	 * @return

	 */

	public Transition getTransition(ComponentValue reference, ComponentValue target)  throws TransitionNotFoundException {

		// check if transition exists

		if (!this.transitions.containsKey(reference) || !this.transitions.get(reference).containsKey(target)) {

			// transition not found

			throw new TransitionNotFoundException("No transition found between values [reference= " + reference + " target= " + target + "]");

		}

		// check transitions

		return this.transitions.get(reference).get(target);

	}

	/**

	 * Returns the direct successors of the value according to

	 * the transition function of the State Variable

	 * 

	 * @param value

	 * @return

	 */

	public List<ComponentValue> getDirectSuccessors(ComponentValue value) {

		// get successors as a list

		return new ArrayList<>(this.transitions.get(value).keySet());

	}

	/**

	 * Returns the direct predecessors of the value according to 

	 * the transition function of the State Variable

	 * 

	 * @param value

	 * @return

	 */

	/**

	 * Analyze the state machine of the SV to extract the shortest acyclic path between two values.

	 * 

	 * @param source

	 * @param target

	 * @return

	 */

	public ValuePath getShortestPath(ComponentValue source, ComponentValue target) {

		// call recursive method to unfold state variable description and build possible paths

		ValuePath path = this.bfs(source, target);

		// get the shortest path

		return path;

	}

	/**

	 * Compute the shortest path from a source to the target through Breadth-First search

	 * 

	 * @param source

	 * @param target

	 * @param path

	 * @param fringe

	 * @return

	 */

	private ValuePath bfs(ComponentValue source, ComponentValue target) {

		// initialize fringe

		List<ComponentValue> fringe = new ArrayList<>();

		// visited values

		Set<ComponentValue> visited = new HashSet<>();

		// initialize the associative map to keep track of parents

		Map<ComponentValue, ComponentValue> parents = new HashMap<>();

		// set the fringe

		for (ComponentValue succ : this.getDirectSuccessors(source) ) {

			// add to fringe

			fringe.add(succ);

			// update parent index

			parents.put(succ, source);

		}

		// add the first step

		visited.add(source);

		// initialize parent map

		parents.put(source, null);

		// set last value

		ComponentValue last = source;

		// explore the fringe

		while (!fringe.isEmpty()) {

			// get the first value from the fringe

			ComponentValue value = fringe.remove(0);

			// check value

			if (value.equals(target)) {

				// update last value and stop the search

				last = value;

				// stop the search

				break;

			} else {

				// check if already visited

				if (!visited.contains(value) ) {

					// add the value to the set of visited ones

					visited.add(value);

					lastParent = value;

					for (ComponentValue succ : this.getDirectSuccessors(value)) {

						// add to fringe

						fringe.add(succ);

						// set visited parent

						parents.put(succ, lastParent);

					}

					// update last value

					last = value;

				}

			}

		}

		// prepare the path to reconstruct

		ValuePath path = new ValuePath();

		do {

			// add to the head to reconstruct the path from the back

			path.addFirstStep(last);

			// update to the next step by retrieving the parent

			last = parents.get(last);

		} while (last != null);

		// get computed (shortest) path

		return path;

	}

	/**

	 * 

	 */

	@SuppressWarnings("unchecked")

	@Override

	public List<StateVariableValue> getValues() {

		return new ArrayList<StateVariableValue>(this.values);

	}

	/**

	 * 

	 */

	@Override

	public StateVariableValue getValueByName(String name) {

		StateVariableValue value = null;

		for (StateVariableValue v : this.values) {

			if (v.getLabel().equals(name)) {

				value = v;

				break;

			}

		}

		// check if value has been found

		if (value == null) {

		}

		// get value

		return value;

	}

	/**

	 * 

	 */

	@Override

	public String toString() {

		return "{ \"name\": \"" + this.name + "\", \"label\": \"" + this.type.getLabel()+ "\" }";

	}

}