/*
 * Copyright (c) 2015, 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.
 *
 * 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.
 */

//

import java.awt.AWTError;
import java.awt.Toolkit;
import java.util.ArrayList;
import java.util.List;
import java.util.ServiceLoader;
import javax.accessibility.AccessibilityProvider;

public class Load {

    public static void main(String[] args) {
        // args[0]: "pass" or "fail"
        // args[1]: "<first provider name>"
        // args[2]: "<optional second provider name>"

        boolean passExpected = args[0].equals("pass");

        // load one or more AccessibilityProviders.
        try {
            Toolkit.getDefaultToolkit();
        } catch (AWTError e) {
            if (passExpected) {
                throw e;
            }
        }
        // Fill Set with names that were requested.
        // They may or may not be available:
        // - available: FooProvider, BarProvider
        // - not available: NoProvider
        List<String> requestedNames = new ArrayList<>();
        for (int i = 1; i < args.length; ++i) {
            requestedNames.add(args[i]);
        }
        // Toolkit.getDefaultToolkit() already went through all the service 
        // providers, loading and activating the requested ones, but now we need
        // to reload all of them to see if they actually got activated.  When the
        // service providers are activated they change their names to append the
        // string "-activated"
        // Go through the providers that are available, for each one:
        //   If it was activated
        //     If it was requested pass, else fail (throw exception)
        //   else (it was not activated)
        //     If it was not requested pass, else fail (throw exception)
        // If the service loader throws an exception, fail (rethrow)
        // If the requested provider is not found, fail (throw exception)
        ClassLoader cl = ClassLoader.getSystemClassLoader();
        try {
            boolean foundRequestedProvider = false;
            for (AccessibilityProvider p : ServiceLoader.load(AccessibilityProvider.class, cl)) {
                String providerName;
                String s = p.getName();
                int i = s.indexOf("-activated");
                if (i != -1) {  // "-activated" found
                    // An activated provider was found, but was it requested?
                    providerName = s.substring(0, i);
                    if (requestedNames.contains(providerName)) {
                        foundRequestedProvider = true;
                    } else {
                        throw new RuntimeException("Unrequested but activated provider found.");
                    }
                } else {  // "-activated" not found
                    // An un-activated provider was found; was it requested?
                    providerName = s;
                    if (requestedNames.contains(providerName)) {
                        throw new RuntimeException("Requested provider found but not activated.");
                    }
                }
            } // if get to here, no issues, so try next provider
            if (!foundRequestedProvider) {
                throw new RuntimeException("Didn't find requested/activated provider");
            }
        } catch (java.util.ServiceConfigurationError | RuntimeException e) {
            if (passExpected) {
                throw e;
            }
        }
    }

}