/*-
    * #%L
    * prolobjectlink-jpi-jtrolog
    * %%
    * Copyright (C) 2020 - 2021 Prolobjectlink Project
    * %%
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as
    * published by the Free Software Foundation, either version 2.1 of the
   * License, or (at your option) any later version.
   * 
   * This program 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 Lesser Public License for more details.
   * 
   * You should have received a copy of the GNU General Lesser Public
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/lgpl-2.1.html>.
   * #L%
   */
  package io.github.prolobjectlink.prolog.jtrolog;
  
  import java.util.Map.Entry;
  
  import io.github.prolobjectlink.prolog.AbstractCompounds;
  import io.github.prolobjectlink.prolog.PrologEntry;
  import io.github.prolobjectlink.prolog.PrologProvider;
  import io.github.prolobjectlink.prolog.PrologTerm;
  import io.github.prolobjectlink.prolog.PrologTermType;
  
  /**
   * PrologEntry is key-value pair of PrologTerm. Is an implementation of
   * {@link Entry} and {@link PrologTerm}.
   * 
   * @author Jose Zalacain
   * @since 1.1
   */
  public final class JTrologEntry extends AbstractCompounds implements PrologEntry {
  
  	private final PrologTerm key;
  	private PrologTerm value;
  
  	JTrologEntry(PrologProvider provider, PrologTerm key, PrologTerm value) {
  		super(PrologTermType.MAP_ENTRY_TYPE, provider);
  		this.value = value;
  		this.key = key;
  	}
  
  	public PrologTerm getKey() {
  		return key;
  	}
  
  	public PrologTerm getValue() {
  		return value;
  	}
  
  	public PrologTerm setValue(PrologTerm value) {
  		this.value = value;
  		return value;
  	}
  
  	public boolean isList() {
  		return false;
  	}
  
  	public boolean isStructure() {
  		return true;
  	}
  
  	public boolean isEmptyList() {
  		return false;
  	}
  
  	public String getFunctor() {
  		return "-";
  	}
  
  	public int getArity() {
  		return 2;
  	}
  
  	public PrologTerm[] getArguments() {
  		return new PrologTerm[] { key, value };
  	}
  
  	@Override
  	public int hashCode() {
  		int result = 0;
  		final int prime = 31;
  		result = prime * result + ((key == null) ? 0 : key.hashCode());
  		result = prime * result + ((value == null) ? 0 : value.hashCode());
  		return result;
  	}
  
  	@Override
  	public boolean equals(Object obj) {
  		if (this == obj)
  			return true;
 		if (obj == null)
 			return false;
 		if (getClass() != obj.getClass())
 			return false;
 		JTrologEntry other = (JTrologEntry) obj;
 		if (key == null) {
 			if (other.key != null)
 				return false;
 		} else if (!key.equals(other.key)) {
 			return false;
 		}
 		if (value == null) {
 			if (other.value != null)
 				return false;
 		} else if (!value.equals(other.value)) {
 			return false;
 		}
 		return true;
 	}
 
 	@Override
 	public String toString() {
 		return "" + key + "-" + value + "";
 	}
 
 }