package org.drools.base;

/*
 * Copyright 2005 JBoss Inc
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import org.drools.RuntimeDroolsException;
import org.drools.spi.ObjectType;

/**
 * Java class semantics <code>ObjectType</code>.
 *
 * @author <a href="mailto:bob@werken.com">bob@werken.com </a>
 *
 * @version $Id: ClassObjectType.java,v 1.5 2005/02/04 02:13:36 mproctor Exp $
 */
public class ClassObjectType
    implements
    ObjectType,
    Externalizable {

    /**
     *
     */
    private static final long serialVersionUID = 400L;

    /** Java object class. */
    protected Class<?>        cls;

    protected String          clsName;

    protected ValueType       valueType;

    private boolean           isEvent;

    // ------------------------------------------------------------
    // Constructors
    // ------------------------------------------------------------

    public ClassObjectType() {
    }

    /**
     * Creates a new class object type with shadow disabled.
     *
     * @param objectTypeClass
     *            Java object class.
     */
    public ClassObjectType(final Class<?> objectTypeClass) {
        this( objectTypeClass,
              false );
    }

    /**
     * Creates a new class object type
     *
     * @param objectTypeClass the class represented by this class object type
     * @param isEvent true if it is an event class, false otherwise
     */
    public ClassObjectType(final Class<?> objectTypeClass,
                           final boolean isEvent) {
        this.cls = objectTypeClass;
        this.isEvent = isEvent;
        //if (objectTypeClass != null)
        this.clsName = this.cls.getName();
        this.valueType = ValueType.determineValueType( objectTypeClass );
    }

    public ClassObjectType(final String className,
                           final boolean isEvent) {
        this.isEvent = isEvent;
        this.clsName = this.cls.getName();
        //        if (objectTypeClass != null)
        //
        //            this.valueType = ValueType.determineValueType( objectTypeClass );        
    }

    public void readExternal(ObjectInput in) throws IOException,
                                            ClassNotFoundException {
        this.clsName = in.readUTF();
        if ( clsName.equals( "org.drools.InitialFact" ) || clsName.equals( "org.drools.base.DroolsQuery" ) ) {
            // we handle this one especially as it never gets written to the packagestore for rewiring
            try {
                setClassType( getClass().getClassLoader().loadClass( clsName ) );
            } catch ( ClassNotFoundException e ) {
                throw new RuntimeDroolsException( "Unable to resolve class '" + clsName + "'" );
            }
        }        
//        this.valueType = (ValueType) in.readObject();
        this.isEvent = in.readBoolean();
    }

    public void writeExternal(ObjectOutput out) throws IOException {
        out.writeUTF( clsName );
//        out.writeObject( valueType );
        out.writeBoolean( isEvent );
    }

    /**
     * Return the Java object class.
     *
     * @return The Java object class.
     */
    public Class<?> getClassType() {
        return this.cls;
    }

    public String getClassName() {
        return this.clsName;
    }

    public void setClassType(Class<?> cls) {
        this.cls = cls;
        this.valueType = ValueType.determineValueType( cls );
    }

    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    // org.drools.spi.ObjectType
    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

    //    /**
    //     * Determine if the passed <code>Class</code> matches to the object type
    //     * defined by this <code>objectType</code> instance.
    //     *
    //     * @param clazz
    //     *            The <code>Class</code> to test.
    //     *
    //     * @return <code>true</code> if the <code>Class</code> matches this
    //     *         object type, else <code>false</code>.
    //     */
    //    public boolean matchesClass(final Class clazz) {
    //        return getClassType().isAssignableFrom( clazz );
    //    }
    //
    //    /**
    //     * Determine if the passed <code>Object</code> belongs to the object type
    //     * defined by this <code>objectType</code> instance.
    //     *
    //     * @param object
    //     *            The <code>Object</code> to test.
    //     *
    //     * @return <code>true</code> if the <code>Object</code> matches this
    //     *         object type, else <code>false</code>.
    //     */
    //    public boolean matches(final Object object) {
    //        return getClassType().isInstance( object );
    //    }
    //
    //    public boolean isAssignableFrom(Object object) {
    //        return this.objectTypeClass.isAssignableFrom( (Class) object );
    //    }

    public boolean isAssignableFrom(ObjectType objectType) {
        if ( !(objectType instanceof ClassObjectType) ) {
            return false;
        } else {
            return this.cls.isAssignableFrom( ((ClassObjectType) objectType).getClassType() );
        }
    }

    public ValueType getValueType() {
        return this.valueType;
    }

    public boolean isEvent() {
        return isEvent;
    }

    public void setEvent(boolean isEvent) {
        this.isEvent = isEvent;
    }

    public String toString() {
        return "[ClassObjectType " + (this.isEvent ? "event=" : "class=") + getClassType().getName() + "]";
    }

    /**
     * Determine if another object is equal to this.
     *
     * @param object
     *            The object to test.
     *
     * @return <code>true</code> if <code>object</code> is equal to this,
     *         otherwise <code>false</code>.
     */
    public boolean equals(final Object object) {
        if ( this == object ) {
            return true;
        }

        if ( object == null || object.getClass() != ClassObjectType.class ) {
            return false;
        }

        return this.clsName.equals( ((ClassObjectType) object).clsName );
    }

    public int hashCode() {
        return this.clsName.hashCode();
    }

}