/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.mappingsmodel.handles;

import java.util.StringTokenizer;

import org.eclipse.persistence.tools.workbench.mappingsmodel.MWModel;
import org.eclipse.persistence.tools.workbench.mappingsmodel.meta.MWClass;
import org.eclipse.persistence.tools.workbench.mappingsmodel.meta.MWMethod;
import org.eclipse.persistence.tools.workbench.utility.ClassTools;
import org.eclipse.persistence.tools.workbench.utility.node.Node;
import org.eclipse.persistence.tools.workbench.utility.string.StringTools;

import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.mappings.OneToOneMapping;
import org.eclipse.persistence.oxm.XMLDescriptor;

/**
 * MWMethodHandle is used to isolate the painful bits of code
 * necessary to correctly handle references to MWMethods.
 * Since a MWMethod is nested within the XML file
 * for a MWClass, we need to store a reference to a particular
 * method as a pair of instance variables:
 *   - the name of the declaring MWClass
 *   - the signature of the method
 *
 * This causes no end of pain when dealing with TopLink, property
 * change listeners, backward-compatibility, etc.
 */
public final class MWMethodHandle extends MWHandle {

    /**
     * This is the actual method.
     * It is built from the declaring type name and method signature, below.
     */
    private volatile MWMethod method;

    /**
     * The declaring type name and method signature are transient. They
     * are used only to hold their values until postProjectBuild()
     * is called and we can resolve the actual method.
     * We do not keep these in synch with the method itself because
     * we cannot know when the method has been renamed etc.
     */
    private volatile String methodDeclaringTypeName;
    private volatile String methodSignature;

    /**
     * default constructor - for TopLink use only
     */
    private MWMethodHandle() {
        super();
    }

    public MWMethodHandle(MWModel parent, NodeReferenceScrubber scrubber) {
        super(parent, scrubber);
    }

    public MWMethodHandle(MWModel parent, MWMethod method, NodeReferenceScrubber scrubber) {
        super(parent, scrubber);
        this.method = method;
    }


    // ********** instance methods **********

    public MWMethod getMethod() {
        return this.method;
    }

    public void setMethod(MWMethod method) {
        this.method = method;
    }

    protected Node node() {
        return getMethod();
    }

    public MWMethodHandle setScrubber(NodeReferenceScrubber scrubber) {
        this.setScrubberInternal(scrubber);
        return this;
    }

    public void resolveMethodHandles() {
        super.resolveMethodHandles();
        if (this.methodDeclaringTypeName != null && this.methodSignature != null) {
            // the type will never be null - the repository will auto-generate one if necessary
            this.method = this.typeNamed(this.methodDeclaringTypeName).methodWithSignature(this.methodSignature);
        }
        // Ensure methodDeclaringTypeName and the methodSignature are not
        // used by setting them to null....
        // If the XML is corrupt and only one of these attributes is populated,
        // this will cause the populated attribute to be cleared out if the
        // objects are rewritten.
        this.methodDeclaringTypeName = null;
        this.methodSignature = null;
    }

    private String removeArrayTypesFromSignature(String methodSignature) {
        if (methodSignature == null) {
            return null;
        }
        StringBuffer buffer = new StringBuffer(methodSignature.substring(0, methodSignature.indexOf('(') +1));
        String parameters = methodSignature.substring(methodSignature.indexOf('(') + 1, methodSignature.length() -1);
        StringTokenizer tokenizer = new StringTokenizer(parameters, ",");
        while (tokenizer.hasMoreTokens()) {
            String parameterType = tokenizer.nextToken();
            buffer.append(ClassTools.elementTypeNameForClassNamed(parameterType));
            int arrayDepth = ClassTools.arrayDepthForClassNamed(parameterType);
            for(int i = 0; i < arrayDepth; i++) {
                buffer.append("[]");
            }

            if (tokenizer.hasMoreTokens()) {
                buffer.append(",");
            }
        }
        buffer.append(")");
        return buffer.toString();
    }

    /**
     * Override to delegate comparison to the method itself.
     * If the handles being compared are in a collection that is being sorted,
     * NEITHER method should be null.
     */
    public int compareTo(Object o) {
        return this.method.compareTo(((MWMethodHandle) o).method);
    }

    public void toString(StringBuffer sb) {
        if (this.method == null) {
            sb.append("null");
        } else {
            this.method.toString(sb);
        }
    }


    // ********** TopLink methods **********

    public static XMLDescriptor buildDescriptor(){
        XMLDescriptor descriptor = new XMLDescriptor();

        descriptor.setJavaClass(MWMethodHandle.class);

        descriptor.addDirectMapping("methodDeclaringTypeName", "getMethodDeclaringTypeNameForTopLink", "setMethodDeclaringTypeNameForTopLink", "method-declaring-type-name/text()");
        descriptor.addDirectMapping("methodSignature", "getMethodSignatureForTopLink", "setMethodSignatureForTopLink", "method-signature/text()");

        return descriptor;
    }

    public static XMLDescriptor legacy60BuildDescriptor(){
        XMLDescriptor descriptor = new XMLDescriptor();

        descriptor.setJavaClass(MWMethodHandle.class);

        descriptor.addDirectMapping("methodDeclaringTypeName", "getMethodDeclaringTypeNameForTopLink", "setMethodDeclaringTypeNameForTopLink", "method-declaring-type-name/text()");
        descriptor.addDirectMapping("methodSignature", "getMethodSignatureForTopLink", "legacySetMethodSignatureForTopLink", "method-signature/text()");

        return descriptor;
    }

    private String getMethodDeclaringTypeNameForTopLink() {
        return (this.method == null) ? null : this.method.getDeclaringType().getName();
    }

    private void setMethodDeclaringTypeNameForTopLink(String methodDeclaringTypeName) {
        this.methodDeclaringTypeName = methodDeclaringTypeName;
    }

    private String getMethodSignatureForTopLink() {
        return (this.method == null) ? null : method.signature();
    }

    private void setMethodSignatureForTopLink(String methodSignature) {
        this.methodSignature = methodSignature;
    }

    private void legacySetMethodSignatureForTopLink(String legacyMethodSignature) {
        this.methodSignature = removeArrayTypesFromSignature(MWModel.legacyReplaceToplinkDepracatedClassReferencesFromSignature(legacyMethodSignature));
    }

}