content: /**
   * Copyright (c) 2017-2018, the Alpha Team.
   * All rights reserved.
   * 
   * Additional changes made by Siemens.
   * 
   * 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.programs.atoms;
  
  import java.util.Arrays;
  import java.util.List;
  
  import at.ac.tuwien.kr.alpha.api.grounder.Substitution;
  import at.ac.tuwien.kr.alpha.api.programs.Predicate;
  import at.ac.tuwien.kr.alpha.api.programs.VariableNormalizableAtom;
  import at.ac.tuwien.kr.alpha.api.programs.atoms.Atom;
  import at.ac.tuwien.kr.alpha.api.programs.terms.IntervalTerm;
  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.atoms.AbstractAtom;
  import at.ac.tuwien.kr.alpha.commons.programs.terms.Terms;
  import at.ac.tuwien.kr.alpha.commons.util.Util;
  
  /**
   * Helper for treating IntervalTerms in rules.
   *
   * Each IntervalTerm is replaced by a variable and this special IntervalAtom is added to the rule body for generating
   * all bindings of the variable.
   *
   * The first term of this atom is an IntervalTerm while the second term is any Term (if it is a VariableTerm, this will
   * bind to all elements of the interval, otherwise it is a simple check whether the Term is a ConstantTerm<Integer> with
   * the Integer being inside the interval.
   * 
   * Copyright (c) 2017, the Alpha Team.
   */
  public class IntervalAtom extends AbstractAtom implements VariableNormalizableAtom {
  	private static final Predicate PREDICATE = Predicates.getPredicate("_interval", 2, true);
  
  	private final List<Term> terms;
  
  	public IntervalAtom(IntervalTerm intervalTerm, Term intervalRepresentingVariable) {
  		this.terms = Arrays.asList(intervalTerm, intervalRepresentingVariable);
  	}
  
  	@Override
  	public Predicate getPredicate() {
  		return PREDICATE;
  	}
  
  	@Override
  	public List<Term> getTerms() {
  		return terms;
  	}
  
  	@Override
  	public boolean isGround() {
  		for (Term t : this.terms) {
  			if (!t.isGround()) {
  				return false;
  			}
  		}
  		return true;
  	}
  
  	@Override
  	public IntervalLiteral toLiteral(boolean positive) {
  		if (!positive) {
  			throw Util.oops("IntervalLiteral cannot be negated");
  		}
  		return new IntervalLiteral(this);
  	}
  
  	@Override
  	public IntervalLiteral toLiteral() {
  		return toLiteral(true);
  	}
  
  	@Override
  	public String toString() {
  		return Util.join(PREDICATE.getName() + "(", terms, ")");
  	}
  
  	@Override
  	public boolean equals(Object o) {
  		if (this == o) {
  			return true;
  		}
  		if (o == null || getClass() != o.getClass()) {
  			return false;
  		}
  
  		IntervalAtom that = (IntervalAtom) o;
  
  		return terms.equals(that.terms);
  	}
  
  	@Override
  	public int hashCode() {
  		return terms.hashCode();
  	}
  
  	@Override
  	public IntervalAtom substitute(Substitution substitution) {
  		return new IntervalAtom((IntervalTerm) terms.get(0).substitute(substitution), terms.get(1).substitute(substitution));
  	}
  
  	@Override
  	public IntervalAtom normalizeVariables(String prefix, int counterStartingValue) {
  		List<Term> renamedTerms = Terms.renameTerms(terms, prefix, counterStartingValue);
  		return new IntervalAtom((IntervalTerm) renamedTerms.get(0), renamedTerms.get(1));
  	}
  
  	@Override
  	public Atom withTerms(List<Term> newTerms) {
  		if (newTerms.size() != 2) {
  			throw new IllegalArgumentException("Cannot set term list " + Util.join("[", newTerms, "]") + " for interval atom!");
  		}
  		if (!(newTerms.get(0) instanceof IntervalTerm)) {
  			throw new IllegalArgumentException("IntervalAtom requires first term to be an interval term!");
  		}
  		return new IntervalAtom((IntervalTerm) newTerms.get(0), newTerms.get(1));
  	}
  
  }
  