AbstractQuery.java

/*
 * #%L
 * prolobjectlink-jpi
 * %%
 * Copyright (C) 2019 Prolobjectlink Project
 * %%
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 * of this software and associated documentation files (the "Software"), to deal
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 * copies of the Software, and to permit persons to whom the Software is
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 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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package io.github.prolobjectlink.prolog;

import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * Partial implementation of {@link PrologQuery} interface.
 * 
 * @author Jose Zalacain
 * @since 1.0
 */
public abstract class AbstractQuery extends AbstractIterator<Collection<PrologTerm>> implements PrologQuery {

    // engine for execute queries
    protected final AbstractEngine engine;

    public AbstractQuery(AbstractEngine engine) {
        this.engine = engine;
    }

    public final PrologEngine getEngine() {
        return engine;
    }

    public final PrologProvider getProvider() {
        return engine.getProvider();
    }

    protected final <K extends PrologTerm> K toTerm(Object o, Class<K> from) {
        return engine.toTerm(o, from);
    }

    protected final <K extends PrologTerm, V extends Object> Map<String, PrologTerm>[] toTermMapArray(
            Map<String, V>[] map, Class<K> from) {
        return engine.toTermMapArray(map, from);
    }

    protected final <K> K fromTerm(PrologTerm term, Class<K> to) {
        return engine.fromTerm(term, to);
    }

    protected final boolean contains(List<Map<String, PrologTerm>> maps, Map<String, PrologTerm> map) {
        for (Map<String, PrologTerm> m : maps) {
            if (m.equals(map)) {
                return true;
            }
        }
        return false;
    }

    protected final boolean contains(List<PrologTerm[]> arrays, PrologTerm[] array) {
        for (PrologTerm[] a : arrays) {
            if (Arrays.equals(a, array)) {
                return true;
            }
        }
        return false;
    }

    protected final PrologLogger getLogger() {
        return getProvider().getLogger();
    }

    public final Iterator<Collection<PrologTerm>> iterator() {
        return new PrologQueryIterator(this);
    }

    public final boolean hasNext() {
        return hasMoreSolutions();
    }

    public final Collection<PrologTerm> next() {
        // don't check has next
        // don't raise NoSuchElementException
        return nextVariablesSolution().values();
    }

    @Override
    public final void remove() {
        // skip invoking next
        nextSolution();
    }

    public final Map<String, PrologTerm> one() {
        return oneVariablesSolution();
    }

    public final List<Map<String, PrologTerm>> nths(int n) {
        Map<String, PrologTerm>[] maps = nVariablesSolutions(n);
        return Arrays.asList(maps);
    }

    public final Map<String, PrologTerm> more() {
        return nextVariablesSolution();
    }

    public final List<Object> oneResult() {
        PrologTerm[] terms = oneSolution();
        return getProvider().getJavaConverter().toObjectList(terms);
    }

    public final List<Object> nextResult() {
        PrologTerm[] terms = nextSolution();
        return getProvider().getJavaConverter().toObjectList(terms);
    }

    public final List<List<Object>> nResult(int n) {
        PrologTerm[][] terms = allSolutions();
        return getProvider().getJavaConverter().toObjectLists(terms);
    }

    public final List<List<Object>> allResults() {
        PrologTerm[][] terms = allSolutions();
        return getProvider().getJavaConverter().toObjectLists(terms);
    }

    public final Map<String, Object> oneVariablesResult() {
        Map<String, PrologTerm> map = oneVariablesSolution();
        return getProvider().getJavaConverter().toObjectMap(map);
    }

    @Override
    public final Map<String, Object> nextVariablesResult() {
        Map<String, PrologTerm> map = nextVariablesSolution();
        return getProvider().getJavaConverter().toObjectMap(map);
    }

    @Override
    public final List<Map<String, Object>> nVariablesResults(int n) {
        Map<String, PrologTerm>[] maps = nVariablesSolutions(n);
        return getProvider().getJavaConverter().toObjectMaps(maps);
    }

    public final List<Map<String, Object>> allVariablesResults() {
        Map<String, PrologTerm>[] maps = allVariablesSolutions();
        return getProvider().getJavaConverter().toObjectMaps(maps);
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((engine == null) ? 0 : engine.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;
        AbstractQuery other = (AbstractQuery) obj;
        if (engine == null) {
            if (other.engine != null)
                return false;
        } else if (!engine.equals(other.engine)) {
            return false;
        }
        return true;
    }

}