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 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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package com.sun.tools.internal.xjc.reader;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

import javax.activation.MimeType;

import com.sun.tools.internal.xjc.model.CElementPropertyInfo;

import static com.sun.tools.internal.xjc.model.CElementPropertyInfo.CollectionMode.*;

import com.sun.tools.internal.xjc.model.CReferencePropertyInfo;

import com.sun.tools.internal.xjc.model.CTypeRef;

import com.sun.tools.internal.xjc.model.Multiplicity;

import com.sun.tools.internal.xjc.model.nav.NType;

import com.sun.xml.internal.bind.v2.model.core.Element;

import com.sun.xml.internal.bind.v2.model.core.ID;

import java.math.BigInteger;

/**

 * Set of {@link Ref}.

 *

 * @author Kohsuke Kawaguchi

 */

public final class RawTypeSet {

    public final Set<Ref> refs;

    /**

     * True if this type set can form references to types.

     */

    public final Mode canBeTypeRefs;

    /**

     * The occurence of the whole references.

     */

    public final Multiplicity mul;

    // computed inside canBeTypeRefs()

    private CElementPropertyInfo.CollectionMode collectionMode;

    /**

     * Should be called from one of the raw type set builders.

     */

    public RawTypeSet( Set<Ref> refs, Multiplicity m ) {

        this.refs = refs;

        mul = m;

        canBeTypeRefs = canBeTypeRefs();

    }

    public CElementPropertyInfo.CollectionMode getCollectionMode() {

        return collectionMode;

    }

    public boolean isRequired() {

        return mul.min.compareTo(BigInteger.ZERO) == 1;

    }

    /**

     * Represents the possible binding option for this {@link RawTypeSet}.

     */

    public enum Mode {

        /**

         * This {@link RawTypeSet} can be either an reference property or

         * an element property, and XJC recommends element property.

         */

        SHOULD_BE_TYPEREF(0),

        /**

         * This {@link RawTypeSet} can be either an reference property or

         * an element property, and XJC recommends reference property.

         */

        CAN_BE_TYPEREF(1),

        /**

         * This {@link RawTypeSet} can be only bound to a reference property.

         */

        MUST_BE_REFERENCE(2);

        private final int rank;

        Mode(int rank) {

           this.rank = rank;

        }

        Mode or(Mode that) {

            switch(Math.max(this.rank,that.rank)) {

            case 0:     return SHOULD_BE_TYPEREF;

            case 1:     return CAN_BE_TYPEREF;

            case 2:     return MUST_BE_REFERENCE;

            }

            throw new AssertionError();

        }

    }

    /**

     * Returns true if {@link #refs} can form refs of types.

     *

     * If there are multiple {@link Ref}s with the same type,

     * we cannot make them into type refs. Or if any of the {@link Ref}

     * says they cannot be in type refs, we cannot do that either.

     *

     * TODO: just checking if the refs are the same is not suffice.

     * If two refs derive from each other, they cannot form a list of refs

     * (because of a possible ambiguity).

     */

    private Mode canBeTypeRefs() {

        Set<NType> types = new HashSet<NType>();

        collectionMode = mul.isAtMostOnce()?NOT_REPEATED:REPEATED_ELEMENT;

        // the way we compute this is that we start from the most optimistic value,

        // and then gradually degrade as we find something problematic.

        Mode mode = Mode.SHOULD_BE_TYPEREF;

        for( Ref r : refs ) {

            mode = mode.or(r.canBeType(this));

            if(mode== Mode.MUST_BE_REFERENCE)

                return mode;    // no need to continue the processing

            if(!types.add(r.toTypeRef(null).getTarget().getType()))

                return Mode.MUST_BE_REFERENCE;   // collision

            if(r.isListOfValues()) {

                if(refs.size()>1 || !mul.isAtMostOnce())

                    return Mode.MUST_BE_REFERENCE;   // restriction on @XmlList

                collectionMode = REPEATED_VALUE;

            }

        }

        return mode;

    }

    public void addTo(CElementPropertyInfo prop) {

        assert canBeTypeRefs!= Mode.MUST_BE_REFERENCE;

        if(mul.isZero())

            return; // the property can't have any value

        List<CTypeRef> dst = prop.getTypes();

        for( Ref t : refs )

            dst.add(t.toTypeRef(prop));

    }

    public void addTo(CReferencePropertyInfo prop) {

        if(mul.isZero())

            return; // the property can't have any value

        for( Ref t : refs )

            t.toElementRef(prop);

    }

    public ID id() {

        for( Ref t : refs ) {

            ID id = t.id();

            if(id!=ID.NONE)    return id;

        }

        return ID.NONE;

    }

    public MimeType getExpectedMimeType() {

        for( Ref t : refs ) {

            MimeType mt = t.getExpectedMimeType();

            if(mt!=null)    return mt;

        }

        return null;

    }

    /**

     * A reference to something.

     *

     * <p>

     * A {@link Ref} can be either turned into {@link CTypeRef} to form

     * an element property, or {@link Element} to form a reference property.

     */

    public static abstract class Ref {

        /**

         * @param ep

         *      the property to which the returned {@link CTypeRef} will be

         *      added to.

         */

        protected abstract CTypeRef toTypeRef(CElementPropertyInfo ep);

        protected abstract void toElementRef(CReferencePropertyInfo prop);

        /**

         * Can this {@link Ref} be a type ref?

         * @return false to veto.

         * @param parent

         */

        protected abstract Mode canBeType(RawTypeSet parent);

        protected abstract boolean isListOfValues();

        /**

         * When this {@link RawTypeSet} binds to a {@link CElementPropertyInfo},

         * this method is used to determine if the property is ID or not.

         */

        protected abstract ID id();

        /**

         * When this {@link RawTypeSet} binds to a {@link CElementPropertyInfo},

         * this method is used to determine if the property has an associated expected MIME type or not.

         */

        protected MimeType getExpectedMimeType() { return null; }

    }

}