content: /**
   * Copyright (c) 2017 Siemens AG
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   * 
   * 1) Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   * 
   * 2) Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package at.ac.tuwien.kr.alpha.core.solver;
  
  import static at.ac.tuwien.kr.alpha.core.test.util.TestUtils.buildSolverForRegressionTest;
  import static at.ac.tuwien.kr.alpha.core.test.util.TestUtils.runWithTimeout;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Optional;
  import java.util.Random;
  
  import org.junit.jupiter.api.Disabled;
  
  import at.ac.tuwien.kr.alpha.api.AnswerSet;
  import at.ac.tuwien.kr.alpha.api.programs.ASPCore2Program;
  import at.ac.tuwien.kr.alpha.api.programs.atoms.Atom;
  import at.ac.tuwien.kr.alpha.api.programs.terms.Term;
  import at.ac.tuwien.kr.alpha.commons.Predicates;
  import at.ac.tuwien.kr.alpha.commons.programs.Programs;
  import at.ac.tuwien.kr.alpha.commons.programs.Programs.ASPCore2ProgramBuilder;
  import at.ac.tuwien.kr.alpha.commons.programs.atoms.Atoms;
  import at.ac.tuwien.kr.alpha.commons.programs.terms.Terms;
  import at.ac.tuwien.kr.alpha.core.parser.ProgramParserImpl;
  
  public class ThreeColouringRandomGraphTest {
  	
  	private static final long DEBUG_TIMEOUT_FACTOR = 5;
  	
  	@RegressionTest
  	public void testV3E3(RegressionTestConfig cfg) {
  		long timeout = 1000L;
  		runWithTimeout(cfg, timeout, DEBUG_TIMEOUT_FACTOR, () -> testThreeColouring(3, 3, cfg));
  	}
  
  	@RegressionTest
  	@Disabled("disabled to save resources during CI")
  	public void testV10E18(RegressionTestConfig cfg) {
  		long timeout = 10000L;
  		runWithTimeout(cfg, timeout, DEBUG_TIMEOUT_FACTOR, () -> testThreeColouring(10, 18, cfg));
  	}
  
  	@RegressionTest
  	@Disabled("disabled to save resources during CI")
  	public void testV20E38(RegressionTestConfig cfg) {
  		long timeout = 10000L;
  		runWithTimeout(cfg, timeout, DEBUG_TIMEOUT_FACTOR, () -> testThreeColouring(20, 38, cfg));
  	}
  
  	@RegressionTest
  	@Disabled("disabled to save resources during CI")
  	public void testV30E48(RegressionTestConfig cfg) {
  		long timeout = 10000L;
  		runWithTimeout(cfg, timeout, DEBUG_TIMEOUT_FACTOR, () -> testThreeColouring(30, 48, cfg));
  	}
  
  	@RegressionTest
  	@Disabled("disabled to save resources during CI")
  	public void testV200E300(RegressionTestConfig cfg) {
  		long timeout = 60000L;
  		runWithTimeout(cfg, timeout, DEBUG_TIMEOUT_FACTOR, () -> testThreeColouring(200, 300, cfg));
  	}
  
  	@RegressionTest
  	@Disabled("disabled to save resources during CI")
  	public void testV300E200(RegressionTestConfig cfg) {
  		long timeout = 60000L;
  		runWithTimeout(cfg, timeout, DEBUG_TIMEOUT_FACTOR, () -> testThreeColouring(300, 200, cfg));
  	}
  
  	@RegressionTest
  	@Disabled("disabled to save resources during CI")
  	public void testV300E300(RegressionTestConfig cfg) {
  		long timeout = 60000L;
  		runWithTimeout(cfg, timeout, DEBUG_TIMEOUT_FACTOR, () -> testThreeColouring(300, 300, cfg));
  	}
  
  	private void testThreeColouring(int nVertices, int nEdges, RegressionTestConfig cfg) {
  		ASPCore2Program tmpPrg = new ProgramParserImpl().parse(
  				"blue(N) :- v(N), not red(N), not green(N)." +
  				"red(N) :- v(N), not blue(N), not green(N)." +
  				"green(N) :- v(N), not red(N), not blue(N)." +
  				":- e(N1,N2), blue(N1), blue(N2)." +
  				":- e(N1,N2), red(N1), red(N2)." +
  				":- e(N1,N2), green(N1), green(N2).");
  		ASPCore2ProgramBuilder prgBuilder = Programs.builder(tmpPrg);
  		prgBuilder.addFacts(createVertices(nVertices));
  		prgBuilder.addFacts(createEdges(nVertices, nEdges));
  		ASPCore2Program program = prgBuilder.build();
  		maybeShuffle(program);
  
  		@SuppressWarnings("unused")
  		Optional<AnswerSet> answerSet = buildSolverForRegressionTest(program, cfg).stream().findAny();
  		//System.out.println(answerSet);
  
  		// TODO: check correctness of answer set
  	}
  
  	@SuppressWarnings("unused")
  	private void maybeShuffle(ASPCore2Program program) {
  
  		// TODO: switch on if different rule orderings in the encoding are desired (e.g. for benchmarking purposes)
  		// FIXME since InputProgram is immutable this needs to be reworked a bit if used
  		// Collections.reverse(program.getRules());
  		// Collections.shuffle(program.getRules());
  		// Collections.reverse(program.getFacts());
  		// Collections.shuffle(program.getFacts());
  	}
  
  	private List<Atom> createVertices(int n) {
  		List<Atom> facts = new ArrayList<>(n);
  		for (int i = 0; i < n; i++) {
  			facts.add(fact("v", i));
  		}
  		return facts;
  	}
  
  	private List<Atom> createEdges(int vertices, int edges) {
  		Random rand = new Random(0);
  		List<Atom> facts = new ArrayList<>(edges);
  		for (int i = 0; i < edges; i++) {
  			int v1 = 0;
  			int v2 = 0;
  			while (v1 == v2) {
  				v1 = rand.nextInt(vertices);
  				v2 = rand.nextInt(vertices);
  			}
  			facts.add(fact("e", v1, v2));
  			facts.add(fact("e", v2, v1));
  		}
  		return facts;
  	}
  
  	private Atom fact(String predicateName, int... iTerms) {
  		List<Term> terms = new ArrayList<>(1);
  		for (int i : iTerms) {
  			terms.add(Terms.newConstant(i));
  		}
  		return Atoms.newBasicAtom(Predicates.getPredicate(predicateName, iTerms.length), terms);
  	}
  }
  