code: //==============================================================================
  //	
  //	Copyright (c) 2016-
  //	Authors:
  //	* Steffen Maercker <maercker@tcs.inf.tu-dresden.de> (TU Dresden)
  //	* Joachim Klein <klein@tcs.inf.tu-dresden.de> (TU Dresden)
  //	
  //------------------------------------------------------------------------------
  //	
  //	This file is part of PRISM.
  //	
  //	PRISM is free software; you can redistribute it and/or modify
  //	it under the terms of the GNU General Public License as published by
  //	the Free Software Foundation; either version 2 of the License, or
  //	(at your option) any later version.
  //	
  //	PRISM is distributed in the hope that it will be useful,
  //	but WITHOUT ANY WARRANTY; without even the implied warranty of
  //	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  //	GNU General Public License for more details.
  //	
  //	You should have received a copy of the GNU General Public License
  //	along with PRISM; if not, write to the Free Software Foundation,
  //	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  //	
  //==============================================================================
  
  package explicit.modelviews;
  
  import java.io.FileWriter;
  import java.io.IOException;
  import java.util.BitSet;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.PrimitiveIterator;
  import java.util.Map.Entry;
  import java.util.TreeMap;
  
  import common.IteratorTools;
  import prism.ModelType;
  import prism.PrismException;
  import prism.PrismLog;
  import prism.PrismUtils;
  import strat.MDStrategy;
  import explicit.DTMCFromMDPAndMDStrategy;
  import explicit.Distribution;
  import explicit.MDP;
  import explicit.Model;
  import explicit.SuccessorsIterator;
  import explicit.graphviz.Decorator;
  
  /**
   * Base class for an MDP view, i.e., a virtual MDP that is obtained
   * by mapping from some other model on-the-fly.
   * <br>
   * The main job of sub-classes is to provide an appropriate
   * getTransitionsIterator() method. Several other methods, providing
   * meta-data on the model have to be provided as well. For examples,
   * see the sub-classes contained in this package.
   */
  public abstract class MDPView extends ModelView implements MDP, Cloneable
  {
  	public MDPView()
  	{
  		super();
  	}
  
  	public MDPView(final MDPView model)
  	{
  		super(model);
  	}
  
  
  
  	//--- Object ---
  
  	@Override
  	public String toString()
  	{
  		String s = "[ ";
  		for (int state = 0, numStates = getNumStates(); state < numStates; state++) {
  			if (state > 0)
  				s += ", ";
  			s += state + ": ";
  			s += "[";
  			for (int choice = 0, numChoices = getNumChoices(state); choice < numChoices; choice++) {
  				if (choice > 0)
  					s += ",";
  				final Object action = getAction(state, choice);
  				if (action != null)
  					s += action + ":";
  				s += new Distribution(getTransitionsIterator(state, choice));
  			}
  			s += "]";
  		}
  		s += " ]";
  		return s;
  	}
  
  
  
  	//--- Model ---
  
  	@Override
  	public ModelType getModelType()
  	{
  		return ModelType.MDP;
  	}
  
  	@Override
  	public int getNumTransitions()
  	{
  		int numTransitions = 0;
  		for (int state = 0, numStates = getNumStates(); state < numStates; state++) {
  			for (int choice = 0, numChoices = getNumChoices(state); choice < numChoices; choice++)
  				numTransitions += getNumTransitions(state, choice);
  		}
  		return numTransitions;
  	}
  
  	@Override
  	public void exportToPrismExplicitTra(final PrismLog out)
  	{
  		final int numStates = getNumStates();
  		// Output transitions to .tra file
  		out.print(numStates + " " + getNumChoices() + " " + getNumTransitions() + "\n");
  		final TreeMap<Integer, Double> sorted = new TreeMap<>();
  		for (int state = 0; state < numStates; state++) {
  			for (int choice = 0, numChoices = getNumChoices(state); choice < numChoices; choice++) {
  				// Extract transitions and sort by destination state index (to match PRISM-exported files)
  				for (Iterator<Entry<Integer, Double>> transitions = getTransitionsIterator(state, choice); transitions.hasNext();) {
  					final Entry<Integer, Double> trans = transitions.next();
  					sorted.put(trans.getKey(), trans.getValue());
  				}
  				// Print out (sorted) transitions
  				for (Entry<Integer, Double> e : sorted.entrySet()) {
  					// Note use of PrismUtils.formatDouble to match PRISM-exported files
  					out.print(state + " " + choice + " " + e.getKey() + " " + PrismUtils.formatDouble(e.getValue()));
  					final Object action = getAction(state, choice);
  					out.print(action == null ? "\n" : (" " + action + "\n"));
  				}
  				sorted.clear();
  			}
  		}
  	}
  
  	@Override
  	public void exportToPrismLanguage(final String filename) throws PrismException
  	{
  		try (FileWriter out = new FileWriter(filename)) {
  			// Output transitions to PRISM language file
  			out.write(getModelType().keyword() + "\n");
  			final int numStates = getNumStates();
  			out.write("module M\nx : [0.." + (numStates - 1) + "];\n");
  			final TreeMap<Integer, Double> sorted = new TreeMap<Integer, Double>();
  			for (int state = 0; state < numStates; state++) {
  				for (int choice = 0, numChoices = getNumChoices(state); choice < numChoices; choice++) {
  					// Extract transitions and sort by destination state index (to match PRISM-exported files)
  					for (Iterator<Entry<Integer, Double>> transitions = getTransitionsIterator(state, choice); transitions.hasNext();) {
  						final Entry<Integer, Double> trans = transitions.next();
  						sorted.put(trans.getKey(), trans.getValue());
  					}
  					// Print out (sorted) transitions
  					final Object action = getAction(state, choice);
  					out.write(action != null ? ("[" + action + "]") : "[]");
  					out.write("x=" + state + "->");
  					boolean first = true;
  					for (Entry<Integer, Double> e : sorted.entrySet()) {
  						if (first)
  							first = false;
  						else
  							out.write("+");
  						// Note use of PrismUtils.formatDouble to match PRISM-exported files
  						out.write(PrismUtils.formatDouble(e.getValue()) + ":(x'=" + e.getKey() + ")");
  					}
  					out.write(";\n");
  					sorted.clear();
  				}
  			}
  			out.write("endmodule\n");
  		} catch (IOException e) {
  			throw new PrismException("Could not export " + getModelType() + " to file \"" + filename + "\"" + e);
  		}
  	}
  
  	@Override
  	public String infoString()
  	{
  		final int numStates = getNumStates();
  		String s = "";
  		s += numStates + " states (" + getNumInitialStates() + " initial)";
  		s += ", " + getNumTransitions() + " transitions";
  		s += ", " + getNumChoices() + " choices";
  		s += ", dist max/avg = " + getMaxNumChoices() + "/" + PrismUtils.formatDouble2dp(((double) getNumChoices()) / numStates);
  		return s;
  	}
  
  	@Override
  	public String infoStringTable()
  	{
  		final int numStates = getNumStates();
  		String s = "";
  		s += "States:      " + numStates + " (" + getNumInitialStates() + " initial)\n";
  		s += "Transitions: " + getNumTransitions() + "\n";
  		s += "Choices:     " + getNumChoices() + "\n";
  		s += "Max/avg:     " + getMaxNumChoices() + "/" + PrismUtils.formatDouble2dp(((double) getNumChoices()) / numStates) + "\n";
  		return s;
  	}
  
  	//--- NondetModel ---
  
  	@Override
  	public int getNumChoices()
  	{
  		int numChoices = 0;
  		for (int state = 0, numStates = getNumStates(); state < numStates; state++) {
  			numChoices += getNumChoices(state);
  		}
  		return numChoices;
  	}
  
  	@Override
  	public int getMaxNumChoices()
  	{
  		int maxNumChoices = 0;
  		for (int state = 0, numStates = getNumStates(); state < numStates; state++) {
  			maxNumChoices = Math.max(maxNumChoices, getNumChoices(state));
  		}
  		return maxNumChoices;
  	}
  
  	@Override
  	public boolean areAllChoiceActionsUnique()
  	{
  		final HashSet<Object> actions = new HashSet<Object>();
  		for (int state = 0, numStates = getNumStates(); state < numStates; state++) {
  			final int numChoices = getNumChoices(state);
  			if (numChoices <= 1) {
  				continue;
  			}
  			actions.clear();
  			for (int choice = 0; choice < numChoices; choice++) {
  				if (!actions.add(getAction(state, choice))) {
  					return false;
  				}
  			}
  		}
  		return true;
  	}
  
  	@Override
  	public int getNumTransitions(final int state, final int choice)
  	{
  		return IteratorTools.count(getTransitionsIterator(state, choice));
  	}
  
  	@Override
  	public SuccessorsIterator getSuccessors(final int state, final int choice)
  	{
  		final Iterator<Entry<Integer, Double>> transitions = getTransitionsIterator(state, choice);
  
  		return SuccessorsIterator.from(new PrimitiveIterator.OfInt() {
  			public boolean hasNext() {return transitions.hasNext();}
  			public int nextInt() {return transitions.next().getKey();}
  		}, true);
  	}
  
  	@Override
  	public Model constructInducedModel(final MDStrategy strat)
  	{
  		return new DTMCFromMDPAndMDStrategy(this, strat);
  	}
  
  	@Override
  	public void exportToDotFileWithStrat(final PrismLog out, final BitSet mark, final int[] strat)
  	{
  		out.print("digraph " + getModelType() + " {\nnode [shape=box];\n");
  		for (int state = 0, numStates = getNumStates(); state < numStates; state++) {
  			if (mark != null && mark.get(state))
  				out.print(state + " [style=filled  fillcolor=\"#cccccc\"]\n");
  			for (int choice = 0, numChoices = getNumChoices(state); choice < numChoices; choice++) {
  				final String style = (strat[state] == choice) ? ",color=\"#ff0000\",fontcolor=\"#ff0000\"" : "";
  				final Object action = getAction(state, choice);
  				final String nij = "n" + state + "_" + choice;
  				out.print(state + " -> " + nij + " [ arrowhead=none,label=\"" + choice);
  				if (action != null) {
  					out.print(":" + action);
  				}
  				out.print("\"" + style + " ];\n");
  				out.print(nij + " [ shape=point,height=0.1,label=\"\"" + style + " ];\n");
  				for (Iterator<Entry<Integer, Double>> transitions = getTransitionsIterator(state, choice); transitions.hasNext();) {
  					Entry<Integer, Double> trans = transitions.next();
  					out.print(nij + " -> " + trans.getKey() + " [ label=\"" + trans.getValue() + "\"" + style + " ];\n");
  				}
  			}
  		}
  		out.print("}\n");
  	}
  
  	//--- ModelView ---
  
  	/**
  	 * @see explicit.MDPExplicit#exportTransitionsToDotFile(int, PrismLog) MDPExplicit
  	 **/
  	@Override
  	public void exportTransitionsToDotFile(int i, PrismLog out, Iterable<explicit.graphviz.Decorator> decorators)
  	{
  		int j, numChoices;
  		String nij;
  		Object action;
  		numChoices = getNumChoices(i);
  		for (j = 0; j < numChoices; j++) {
  			action = getAction(i, j);
  			nij = "n" + i + "_" + j;
  			out.print(i + " -> " + nij + " ");
  
  			explicit.graphviz.Decoration d = new explicit.graphviz.Decoration();
  			d.attributes().put("arrowhead", "none");
  			d.setLabel(j + (action != null ? ":" + action : ""));
  
  			if (decorators != null) {
  				for (Decorator decorator : decorators) {
  					d = decorator.decorateTransition(i, j, d);
  				}
  			}
  			out.print(d);
  			out.println(";");
  
  			out.print(nij + " [ shape=point,width=0.1,height=0.1,label=\"\" ];\n");
  
  			Iterator<Map.Entry<Integer, Double>> iter = getTransitionsIterator(i, j);
  			while (iter.hasNext()) {
  				Map.Entry<Integer, Double> e = iter.next();
  				out.print(nij + " -> " + e.getKey() + " ");
  
  				d = new explicit.graphviz.Decoration();
  				d.setLabel(e.getValue().toString());
  
  				if (decorators != null) {
  					for (Decorator decorator : decorators) {
  						d = decorator.decorateProbability(i, e.getKey(), j, e.getValue(), d);
  					}
  				}
  
  				out.print(d);
  				out.println(";");
  			}
  		}
  	}
  }
  