/*
 * $Id$
 *
 * Copyright (c) 2003, 2018, 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
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package com.sun.javatest.batch;

import com.sun.javatest.Harness;
import com.sun.javatest.tool.Command;
import com.sun.javatest.tool.CommandContext;
import com.sun.javatest.util.HelpTree;
import com.sun.javatest.util.I18NResourceBundle;

import java.io.File;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;

class ObserverCommand extends Command {
    private static I18NResourceBundle i18n = I18NResourceBundle.getBundleForClass(BatchManager.class);
    private ClassLoader classLoader;
    private String className;
    private String[] classArgs;

    ObserverCommand(Iterator<String> argIter) throws Fault {
        super(getName());

        Vector<String> v = null;

        while (argIter.hasNext()) {
            String arg = nextArg(argIter);

            if (arg.equals("-cp") && argIter.hasNext()) {
                setClassPath(nextArg(argIter));
            } else if (arg.startsWith("-")) {
                throw new Fault(i18n, "observer.badArg", arg);
            } else {
                className = arg;
                while (argIter.hasNext()) {
                    arg = nextArg(argIter);
                    if (arg.equals("-end")) {
                        break;
                    } else {
                        if (v == null) {
                            v = new Vector<>();
                        }
                        v.add(arg);
                    }
                }
                break;
            }
        }

        if (className == null) {
            throw new Fault(i18n, "observer.noClassName");
        }

        if (v != null) {
            classArgs = v.toArray(new String[v.size()]);
        }
    }

    static String getName() {
        return "observer";
    }

    static HelpTree.Node getHelp() {
        String[] opts = {"cp"};
        return new HelpTree.Node(i18n, "cmgr.help.observer", opts);
    }

    @Override
    public void run(CommandContext ctx) throws Fault {
        try {
            Class<?> oc = loadClass(className);

            Harness.Observer o = null;
            if (classArgs == null || classArgs.length == 0) {
                o = tryConstructor(oc,
                        new Class<?>[]{},
                        new Object[]{});
            } else if (classArgs.length == 1) {
                o = tryConstructor(oc,
                        new Class<?>[]{String.class},
                        new Object[]{classArgs[0]});
            }

            if (o == null) {
                o = tryConstructor(oc,
                        new Class<?>[]{String[].class},
                        new Object[]{classArgs});
            }

            if (o == null) {
                throw new Fault(i18n, "observer.cantFindConstructor", className);
            }

            ctx.addHarnessObserver(o);
        } catch (ClassNotFoundException e) {
            throw new Fault(i18n, "observer.cantFindClass", className);
        } catch (IllegalAccessException e) {
            throw new Fault(i18n, "observer.cantAccessClass", className);
        } catch (InstantiationException | InvocationTargetException e) {
            throw new Fault(i18n, "observer.cantCreateClass", className);
        }
    }

    private Harness.Observer tryConstructor(Class<?> obsClass, Class<?>[] argTypes, Object[] args)
            throws IllegalAccessException, InstantiationException, InvocationTargetException {
        try {
            Constructor<?> c = obsClass.getConstructor(argTypes);
            return (Harness.Observer) c.newInstance(args);
        } catch (NoSuchMethodException e) {
            return null;
        }
    }

    private void setClassPath(String s) throws Fault {
        char pathCh = File.pathSeparatorChar;
        Vector<URL> v = new Vector<>();
        int start = 0;
        for (int i = s.indexOf(pathCh); i != -1; i = s.indexOf(pathCh, start)) {
            addClassPathEntry(s.substring(start, i), v);
            start = i + 1;
        }
        addClassPathEntry(s.substring(start), v);
        setClassPath(v.toArray(new URL[v.size()]));
    }

    private void setClassPath(URL[] path) {
        classLoader = new URLClassLoader(path);
    }

    private Class<?> loadClass(String name) throws ClassNotFoundException {
        return classLoader == null ? Class.forName(name) : classLoader.loadClass(name);
    }

    private void addClassPathEntry(String s, List<URL> v) throws Fault {
        try {
            if (!s.isEmpty()) {
                v.add(new File(s).toURL());
            }
        } catch (MalformedURLException e) {
            throw new Fault(i18n, "observer.badClassPath", s, e);
        }
    }
}
