/*
 * Copyright (c) 2015, 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.
 */
package com.oracle.graal.hotspot;

import static jdk.vm.ci.inittimer.InitTimer.timer;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import jdk.vm.ci.code.Architecture;
import jdk.vm.ci.common.JVMCIError;
import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;
import jdk.vm.ci.inittimer.InitTimer;
import jdk.vm.ci.runtime.JVMCICompilerFactory;
import jdk.vm.ci.runtime.JVMCIRuntime;
import jdk.vm.ci.service.Services;
import sun.misc.VM;

import com.oracle.graal.options.GraalJarsOptionDescriptorsProvider;
import com.oracle.graal.options.Option;
import com.oracle.graal.options.OptionType;
import com.oracle.graal.options.OptionValue;
import com.oracle.graal.options.OptionsParser;
import com.oracle.graal.phases.tiers.CompilerConfiguration;

public abstract class HotSpotGraalCompilerFactory implements JVMCICompilerFactory {

    static {
        initializeOptions();
    }

    static class Options {

        // @formatter:off
        @Option(help = "In tiered mode compile the compiler itself using optimized first tier code.", type = OptionType.Expert)
        public static final OptionValue<Boolean> CompileGraalWithC1Only = new OptionValue<>(true);
        // @formatter:on

    }

    @SuppressWarnings("try")
    private static class Lazy {

        static {
            try (InitTimer t = timer("HotSpotBackendFactory.register")) {
                for (HotSpotBackendFactory backend : Services.load(HotSpotBackendFactory.class)) {
                    backend.register();
                }
            }
        }

        static void registerBackends() {
            // force run of static initializer
        }
    }

    /**
     * Parses the options in the file denoted by the {@linkplain VM#getSavedProperty(String) saved}
     * system property named {@code "graal.options.file"} if the file exists followed by the options
     * encoded in saved system properties whose names start with {@code "graal.option."}.
     */
    @SuppressWarnings("try")
    private static void initializeOptions() {
        try (InitTimer t = timer("InitializeOptions")) {
            boolean jdk8OrEarlier = System.getProperty("java.specification.version").compareTo("1.9") < 0;
            GraalJarsOptionDescriptorsProvider odp = jdk8OrEarlier ? GraalJarsOptionDescriptorsProvider.create() : null;

            String optionsFile = System.getProperty("graal.options.file");

            if (optionsFile != null) {
                File graalOptions = new File(optionsFile);
                if (graalOptions.exists()) {
                    try (BufferedReader br = new BufferedReader(new FileReader(graalOptions))) {
                        String optionSetting = null;
                        int lineNo = 1;
                        List<String> optionSettings = new ArrayList<>();
                        while ((optionSetting = br.readLine()) != null) {
                            if (!optionSetting.isEmpty() && optionSetting.charAt(0) != '#') {
                                try {
                                    OptionsParser.parseOptionSettingTo(optionSetting, optionSettings);
                                } catch (Throwable e) {
                                    throw new InternalError("Error parsing " + graalOptions + ", line " + lineNo, e);
                                }
                            }
                            lineNo++;
                        }
                        try {
                            OptionsParser.parseOptions(optionSettings.toArray(new String[optionSettings.size()]), null, odp, null);
                        } catch (Throwable e) {
                            throw new InternalError("Error parsing an option from " + graalOptions, e);
                        }
                    } catch (IOException e) {
                        throw new InternalError("Error reading " + graalOptions, e);
                    }
                }
            }

            Properties savedProps = getSavedProperties();

            List<String> optionSettings = new ArrayList<>();
            for (Map.Entry<Object, Object> e : savedProps.entrySet()) {
                String name = (String) e.getKey();
                if (name.startsWith("graal.option.")) {
                    String value = (String) e.getValue();
                    optionSettings.add(name.substring("graal.option.".length()));
                    optionSettings.add(value);
                }
            }

            OptionsParser.parseOptions(optionSettings.toArray(new String[optionSettings.size()]), null, odp, null);
        }
    }

    private static Properties getSavedProperties() {
        try {
            Field savedPropsField = VM.class.getDeclaredField("savedProps");
            savedPropsField.setAccessible(true);
            return (Properties) savedPropsField.get(null);
        } catch (Exception e) {
            throw new JVMCIError(e);
        }
    }

    protected abstract HotSpotBackendFactory getBackendFactory(Architecture arch);

    protected abstract CompilerConfiguration createCompilerConfiguration();

    @SuppressWarnings("try")
    @Override
    public HotSpotGraalCompiler createCompiler(JVMCIRuntime runtime) {
        HotSpotJVMCIRuntime jvmciRuntime = (HotSpotJVMCIRuntime) runtime;
        try (InitTimer t = timer("HotSpotGraalRuntime.<init>")) {
            Lazy.registerBackends();
            HotSpotGraalRuntime graalRuntime = new HotSpotGraalRuntime(jvmciRuntime, this);
            HotSpotGraalVMEventListener.addRuntime(graalRuntime);
            return new HotSpotGraalCompiler(jvmciRuntime, graalRuntime);
        }
    }

    @Override
    public String[] getTrivialPrefixes() {
        if (Options.CompileGraalWithC1Only.getValue()) {
            return new String[]{"jdk/vm/ci", "com/oracle/graal"};
        }
        return null;
    }
}