/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * 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

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * 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,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * This source code is provided to illustrate the usage of a given feature

 * or technique and has been deliberately simplified. Additional steps

 * required for a production-quality application, such as security checks,

 * input validation and proper error handling, might not be present in

 * this sample code.

 */

package com.sun.tools.example.debug.tty;

import com.sun.jdi.*;

import com.sun.jdi.request.EventRequest;

import com.sun.jdi.request.ExceptionRequest;

import com.sun.jdi.request.ClassPrepareRequest;

import com.sun.jdi.event.ClassPrepareEvent;

import java.util.ArrayList;

abstract class EventRequestSpec {

    final ReferenceTypeSpec refSpec;

    int suspendPolicy = EventRequest.SUSPEND_ALL;

    EventRequest resolved = null;

    ClassPrepareRequest prepareRequest = null;

    EventRequestSpec(ReferenceTypeSpec refSpec) {

        this.refSpec = refSpec;

    }

    /**

     * The 'refType' is known to match, return the EventRequest.

     */

    abstract EventRequest resolveEventRequest(ReferenceType refType)

                                           throws Exception;

    /**

     * @return If this EventRequestSpec matches the 'refType'

     * return the cooresponding EventRequest.  Otherwise

     * return null.

     */

    synchronized EventRequest resolve(ClassPrepareEvent event) throws Exception {

        if ((resolved == null) &&

            (prepareRequest != null) &&

            prepareRequest.equals(event.request())) {

            resolved = resolveEventRequest(event.referenceType());

            prepareRequest.disable();

            Env.vm().eventRequestManager().deleteEventRequest(prepareRequest);

            prepareRequest = null;

            if (refSpec instanceof PatternReferenceTypeSpec) {

                PatternReferenceTypeSpec prs = (PatternReferenceTypeSpec)refSpec;

                if (! prs.isUnique()){

                    /*

                     * Class pattern event requests are never

                     * considered "resolved", since future class loads

                     * might also match.

                     * Create and enable a new ClassPrepareRequest to

                     * keep trying to resolve.

                     */

                    resolved = null;

                    prepareRequest = refSpec.createPrepareRequest();

                    prepareRequest.enable();

                }

            }

        }

        return resolved;

    }

    synchronized void remove() {

        if (isResolved()) {

            Env.vm().eventRequestManager().deleteEventRequest(resolved());

        }

        if (refSpec instanceof PatternReferenceTypeSpec) {

            PatternReferenceTypeSpec prs = (PatternReferenceTypeSpec)refSpec;

            if (! prs.isUnique()){

                /*

                 * This is a class pattern.  Track down and delete

                 * all EventRequests matching this spec.

                 * Note: Class patterns apply only to ExceptionRequests,

                 * so that is all we need to examine.

                 */

                ArrayList<ExceptionRequest> deleteList = new ArrayList<ExceptionRequest>();

                for (ExceptionRequest er :

                         Env.vm().eventRequestManager().exceptionRequests()) {

                    if (prs.matches(er.exception())) {

                        deleteList.add (er);

                    }

                }

                Env.vm().eventRequestManager().deleteEventRequests(deleteList);

            }

        }

    }

    private EventRequest resolveAgainstPreparedClasses() throws Exception {

        for (ReferenceType refType : Env.vm().allClasses()) {

            if (refType.isPrepared() && refSpec.matches(refType)) {

                resolved = resolveEventRequest(refType);

            }

        }

        return resolved;

    }

    synchronized EventRequest resolveEagerly() throws Exception {

        try {

            if (resolved == null) {

                /*

                 * Not resolved.  Schedule a prepare request so we

                 * can resolve later.

                 */

                prepareRequest = refSpec.createPrepareRequest();

                prepareRequest.enable();

                // Try to resolve in case the class is already loaded.

                resolveAgainstPreparedClasses();

                if (resolved != null) {

                    prepareRequest.disable();

                    Env.vm().eventRequestManager().deleteEventRequest(prepareRequest);

                    prepareRequest = null;

                }

            }

            if (refSpec instanceof PatternReferenceTypeSpec) {

                PatternReferenceTypeSpec prs = (PatternReferenceTypeSpec)refSpec;

                if (! prs.isUnique()){

                    /*

                     * Class pattern event requests are never

                     * considered "resolved", since future class loads

                     * might also match.  Create a new

                     * ClassPrepareRequest if necessary and keep

                     * trying to resolve.

                     */

                    resolved = null;

                    if (prepareRequest == null) {

                        prepareRequest = refSpec.createPrepareRequest();

                        prepareRequest.enable();

                    }

                }

            }

        } catch (VMNotConnectedException e) {

            // Do nothing. Another resolve will be attempted when the

            // VM is started.

        }

        return resolved;

    }

    /**

     * @return the eventRequest this spec has been resolved to,

     * null if so far unresolved.

     */

    EventRequest resolved() {

        return resolved;

    }

    /**

     * @return true if this spec has been resolved.

     */

    boolean isResolved() {

        return resolved != null;

    }

    protected boolean isJavaIdentifier(String s) {

        if (s.length() == 0) {

            return false;

        }

        int cp = s.codePointAt(0);

        if (! Character.isJavaIdentifierStart(cp)) {

            return false;

        }

        for (int i = Character.charCount(cp); i < s.length(); i += Character.charCount(cp)) {

            cp = s.codePointAt(i);

            if (! Character.isJavaIdentifierPart(cp)) {

                return false;

            }

        }

        return true;

    }

    String errorMessageFor(Exception e) {

        if (e instanceof IllegalArgumentException) {

            return (MessageOutput.format("Invalid command syntax"));

        } else if (e instanceof RuntimeException) {

            // A runtime exception that we were not expecting

            throw (RuntimeException)e;

        } else {

            return (MessageOutput.format("Internal error; unable to set",

                                         this.refSpec.toString()));

        }

    }

}