/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * 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.

 */

package sun.tools.common;

import java.net.URISyntaxException;

import java.util.ArrayList;

import java.util.Collection;

import java.util.List;

import com.sun.tools.attach.VirtualMachine;

import com.sun.tools.attach.VirtualMachineDescriptor;

import sun.jvmstat.monitor.MonitorException;

import sun.jvmstat.monitor.MonitoredHost;

import sun.jvmstat.monitor.MonitoredVm;

import sun.jvmstat.monitor.MonitoredVmUtil;

import sun.jvmstat.monitor.VmIdentifier;

/**

 * Class for finding process matching a process argument,

 * excluding tool it self and returning a list containing

 * the process identifiers.

 */

public class ProcessArgumentMatcher {

    private String excludeCls;

    private String matchClass = null;

    private String singlePid = null;

    private boolean matchAll = false;

    public ProcessArgumentMatcher(String pidArg, Class<?> excludeClass) {

        excludeCls = excludeClass.getName();

        if (pidArg == null || pidArg.isEmpty()) {

            throw new IllegalArgumentException("Pid string is invalid");

        }

        if (pidArg.charAt(0) == '-') {

            throw new IllegalArgumentException("Unrecognized " + pidArg);

        }

        try {

            long pid = Long.parseLong(pidArg);

            if (pid == 0) {

                matchAll = true;

            } else {

                singlePid = String.valueOf(pid);

            }

        } catch (NumberFormatException nfe) {

            matchClass = pidArg;

        }

    }

    private boolean check(VirtualMachineDescriptor vmd) {

        String mainClass = null;

        try {

            VmIdentifier vmId = new VmIdentifier(vmd.id());

            MonitoredHost monitoredHost = MonitoredHost.getMonitoredHost(vmId);

            MonitoredVm monitoredVm = monitoredHost.getMonitoredVm(vmId, -1);

            mainClass = MonitoredVmUtil.mainClass(monitoredVm, true);

            monitoredHost.detach(monitoredVm);

        } catch (NullPointerException npe) {

            // There is a potential race, where a running java app is being

            // queried, unfortunately the java app has shutdown after this

            // method is started but before getMonitoredVM is called.

            // If this is the case, then the /tmp/hsperfdata_xxx/pid file

            // will have disappeared and we will get a NullPointerException.

            // Handle this gracefully....

            return false;

        } catch (MonitorException | URISyntaxException e) {

            if (e.getMessage() != null) {

                System.err.println(e.getMessage());

            } else {

                Throwable cause = e.getCause();

                if ((cause != null) && (cause.getMessage() != null)) {

                    System.err.println(cause.getMessage());

                } else {

                    e.printStackTrace();

                }

            }

            return false;

        }

        if (mainClass.equals(excludeCls)) {

            return false;

        }

        if (matchAll || mainClass.indexOf(matchClass) != -1) {

            return true;

        }

        return false;

    }

    public Collection<String> getPids() {

        Collection<String> pids = new ArrayList<>();

        if (singlePid != null) {

            pids.add(singlePid);

            return pids;

        }

        List<VirtualMachineDescriptor> vmds = VirtualMachine.list();

        for (VirtualMachineDescriptor vmd : vmds) {

            if (check(vmd)) {

                pids.add(vmd.id());

            }

        }

        return pids;

    }

}