package org.sat4j.multicore;
   
   import java.io.PrintStream;
   import java.io.PrintWriter;
   import java.util.Map;
   
   import org.sat4j.core.ASolverFactory;
   import org.sat4j.specs.ContradictionException;
   import org.sat4j.specs.IConstr;
  import org.sat4j.specs.ISolver;
  import org.sat4j.specs.IVec;
  import org.sat4j.specs.IVecInt;
  import org.sat4j.specs.TimeoutException;
  
  public class ManyCore implements ISolver, OutcomeListener {
  
  	/**
  	 * 
  	 */
  	private static final long serialVersionUID = 1L;
  
  	private String[] availableSolvers; // = { };
  
  	private ISolver[] solvers;
  	private int numberOfSolvers;
  	private int winnerId;
  	private boolean needToWait;
  	private boolean resultFound;
  	private int remainingSolvers;
  
  	public ManyCore(ASolverFactory<? extends ISolver> factory, String ... solverNames) {
  		availableSolvers = solverNames;
  		Runtime runtime = Runtime.getRuntime();
  		long memory = runtime.maxMemory();
  		int numberOfCores = runtime.availableProcessors();
  		if (memory > 1000000000L) {
  			numberOfSolvers = numberOfCores;
  		} else {
  			numberOfSolvers = 1;
  		}
  		if (solverNames.length<numberOfSolvers) {
  			throw new IllegalArgumentException("I need more solver names to run ManyCore on such computer!");
  		}
  		solvers = new ISolver[numberOfSolvers];
  		for (int i = 0; i < numberOfSolvers; i++) {
  			solvers[i] = factory.createSolverByName(
  					availableSolvers[i]);
  		}
  	}
  
  	public void addAllClauses(IVec<IVecInt> clauses)
  			throws ContradictionException {
  		for (int i = 0; i < numberOfSolvers; i++) {
  			solvers[i].addAllClauses(clauses);
  		}
  	}
  
  	public IConstr addAtLeast(IVecInt literals, int degree)
  			throws ContradictionException {
  		for (int i = 0; i < numberOfSolvers; i++) {
  			solvers[i].addAtLeast(literals, degree);
  		}
  		return null;
  	}
  
  	public IConstr addAtMost(IVecInt literals, int degree)
  			throws ContradictionException {
  		for (int i = 0; i < numberOfSolvers; i++) {
  			solvers[i].addAtMost(literals, degree);
  		}
  		return null;
  	}
  
  	public IConstr addClause(IVecInt literals) throws ContradictionException {
  		for (int i = 0; i < numberOfSolvers; i++) {
  			solvers[i].addClause(literals);
  		}
  		return null;
  	}
  
  	public void clearLearntClauses() {
  		for (int i = 0; i < numberOfSolvers; i++) {
  			solvers[i].clearLearntClauses();
  		}
  	}
  
  	public void expireTimeout() {
  		for (int i = 0; i < numberOfSolvers; i++) {
  			solvers[i].expireTimeout();
  		}
  	}
  
  	public Map<String, Number> getStat() {
  		return solvers[winnerId].getStat();
  	}
  
  	public int getTimeout() {
  		return solvers[0].getTimeout();
  	}
 
 	public long getTimeoutMs() {
 		return solvers[0].getTimeoutMs();
 	}
 	
 	public int newVar() {
 		throw new UnsupportedOperationException();
 	}
 
 	public int newVar(int howmany) {
 		int result = 0;
 		for (int i = 0; i < numberOfSolvers; i++) {
 			result = solvers[i].newVar(howmany);
 		}
 		return result;
 	}
 
 	@Deprecated
 	public void printStat(PrintStream out, String prefix) {
 		solvers[winnerId].printStat(out, prefix);
 	}
 
 	public void printStat(PrintWriter out, String prefix) {
 		solvers[winnerId].printStat(out, prefix);
 	}
 
 	public boolean removeConstr(IConstr c) {
 		throw new UnsupportedOperationException();
 	}
 
 	public void reset() {
 		for (int i = 0; i < numberOfSolvers; i++) {
 			solvers[i].reset();
 		}
 	}
 
 	public void setExpectedNumberOfClauses(int nb) {
 		for (int i = 0; i < numberOfSolvers; i++) {
 			solvers[i].setExpectedNumberOfClauses(nb);
 		}
 	}
 
 	public void setTimeout(int t) {
 		for (int i = 0; i < numberOfSolvers; i++) {
 			solvers[i].setTimeout(t);
 		}
 	}
 
 	public void setTimeoutMs(long t) {
 		for (int i = 0; i < numberOfSolvers; i++) {
 			solvers[i].setTimeoutMs(t);
 		}
 	}
 
 	public void setTimeoutOnConflicts(int count) {
 		for (int i = 0; i < numberOfSolvers; i++) {
 			solvers[i].setTimeoutOnConflicts(count);
 		}
 	}
 
 	public String toString(String prefix) {
 		StringBuffer res = new StringBuffer();
 		res.append("ManyCore solver with ");
 		res.append(numberOfSolvers);
         res.append(" solvers running in parallel");
         res.append("\n");
         for (int i=0;i<numberOfSolvers;i++) {
         	res.append(solvers[i].toString(prefix));
         	res.append("\n");
         }
 		return res.toString();
 	}
 
 	public int[] findModel() throws TimeoutException {
 		throw new UnsupportedOperationException();
 	}
 
 	public int[] findModel(IVecInt assumps) throws TimeoutException {
 		throw new UnsupportedOperationException();
 	}
 
 	public boolean isSatisfiable() throws TimeoutException {
 		remainingSolvers = numberOfSolvers;
 		needToWait = true;
 		for (int i = 0; i < numberOfSolvers; i++) {
 			new Thread(new RunnableSolver(i, solvers[i], this)).start();
 		}
 		try {
 			do {
 				Thread.sleep(1000);
 			} while (needToWait && remainingSolvers > 0);
 		} catch (InterruptedException e) {
 			// TODO: handle exception
 		}
 		if (remainingSolvers == 0) {
 			throw new TimeoutException();
 		}
 		return resultFound;
 	}
 
 	public boolean isSatisfiable(IVecInt assumps, boolean globalTimeout)
 			throws TimeoutException {
 		throw new UnsupportedOperationException();
 	}
 
 	public boolean isSatisfiable(boolean globalTimeout) throws TimeoutException {
 		throw new UnsupportedOperationException();
 	}
 
 	public boolean isSatisfiable(IVecInt assumps) throws TimeoutException {
 		throw new UnsupportedOperationException();
 	}
 
 	public int[] model() {
 		return solvers[winnerId].model();
 	}
 
 	public boolean model(int var) {
 		return solvers[winnerId].model(var);
 	}
 
 	public int nConstraints() {
 		return solvers[0].nConstraints();
 	}
 
 	public int nVars() {
 		return solvers[0].nVars();
 	}
 
 	public void printInfos(PrintWriter out, String prefix) {
 		for (int i = 0; i < numberOfSolvers; i++) {
 			solvers[i].printInfos(out, prefix);
 		}
 	}
 
 	public synchronized void onFinishWithAnswer(boolean finished,
 			boolean result, int index) {
 		if (finished) {
 			winnerId = index;
 			resultFound = result;
 			for (int i = 0; i < numberOfSolvers; i++) {
 				if (i != winnerId)
 					solvers[i].expireTimeout();
 			}
 			System.out.println("c And the winner is "+availableSolvers[winnerId]);
 			needToWait = false;
 		} else {
 			remainingSolvers--;
 		}
 	}
 
 	public boolean isDBSimplificationAllowed() {
 		return solvers[0].isDBSimplificationAllowed();
 	}
 
 	public void setDBSimplificationAllowed(boolean status) {
 		for (int i = 0; i < numberOfSolvers; i++) {
 			solvers[i].setDBSimplificationAllowed(status);
 		}		
 	}
 
 }
 
 interface OutcomeListener {
 	void onFinishWithAnswer(boolean finished, boolean result, int index);
 }
 
 class RunnableSolver implements Runnable {
 
 	private final int index;
 	private final ISolver solver;
 	private final OutcomeListener ol;
 
 	public RunnableSolver(int i, ISolver solver, OutcomeListener ol) {
 		index = i;
 		this.solver = solver;
 		this.ol = ol;
 	}
 
 	public void run() {
 		try {
 			boolean result = solver.isSatisfiable();
 			ol.onFinishWithAnswer(true, result, index);
 		} catch (TimeoutException e) {
 			ol.onFinishWithAnswer(false, false, index);
 		}
 	}
 
 }