/*
 * Copyright (c) 2014, 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.codegen;

import java.io.*;
import java.lang.reflect.*;
import java.util.*;
import java.util.zip.*;

import com.oracle.graal.api.runtime.*;
import com.oracle.graal.compiler.common.*;
import com.oracle.graal.hotspot.*;
import com.oracle.graal.options.*;

/**
 * Command line utility for generating the source code of {@code GraalRuntime.inline.hpp}.
 */
public class GenGraalRuntimeInlineHpp {

    public static void main(String[] args) {
        PrintStream out = System.out;
        try {
            genGetServiceImpls(out);
            genSetOption(out);
        } catch (Throwable t) {
            t.printStackTrace(out);
        }
        out.flush();
    }

    /**
     * Generates code for {@code GraalRuntime::get_service_impls()}.
     */
    private static void genGetServiceImpls(PrintStream out) throws Exception {
        String graalJar = null;
        String classPath = System.getProperty("java.class.path");
        for (String e : classPath.split(File.pathSeparator)) {
            if (e.endsWith("graal.jar")) {
                graalJar = e;
                break;
            }
        }
        final List<Class<? extends Service>> services = new ArrayList<>();
        final ZipFile zipFile = new ZipFile(new File(Objects.requireNonNull(graalJar, "Could not find graal.jar on class path: " + classPath)));
        for (final Enumeration<? extends ZipEntry> e = zipFile.entries(); e.hasMoreElements();) {
            final ZipEntry zipEntry = e.nextElement();
            String name = zipEntry.getName();
            if (name.startsWith("META-INF/services/")) {
                String serviceName = name.substring("META-INF/services/".length());
                Class<?> c = Class.forName(serviceName);
                if (Service.class.isAssignableFrom(c)) {
                    @SuppressWarnings("unchecked")
                    Class<? extends Service> sc = (Class<? extends Service>) c;

                    services.add(sc);
                }
            }
        }

        out.println("Handle GraalRuntime::get_service_impls(KlassHandle serviceKlass, TRAPS) {");
        for (Class<?> service : services) {
            out.printf("  if (serviceKlass->name()->equals(\"%s\")) {%n", toInternalName(service));
            List<Class<?>> impls = new ArrayList<>();
            for (Object impl : ServiceLoader.load(service)) {
                impls.add(impl.getClass());
            }

            out.printf("    objArrayOop servicesOop = oopFactory::new_objArray(serviceKlass(), %d, CHECK_NH);%n", impls.size());
            out.println("    objArrayHandle services(THREAD, servicesOop);");
            for (int i = 0; i < impls.size(); i++) {
                String name = toInternalName(impls.get(i));
                out.printf("    %sservice = create_Service(\"%s\", CHECK_NH);%n", (i == 0 ? "Handle " : ""), name);
                out.printf("    services->obj_at_put(%d, service());%n", i);
            }
            out.println("    return services;");
            out.println("  }");
        }
        out.println("  return Handle();");
        out.println("}");
    }

    /**
     * Generates code for {@code GraalRuntime::set_option()}.
     */
    private static void genSetOption(PrintStream out) throws Exception {
        SortedMap<String, OptionDescriptor> options = getOptions();

        Set<Integer> lengths = new TreeSet<>();
        for (String s : options.keySet()) {
            lengths.add(s.length());
        }
        lengths.add("PrintFlags".length());

        out.println("bool GraalRuntime::set_option(KlassHandle hotSpotOptionsClass, const char* name, int name_len, Handle name_handle, const char* value, TRAPS) {");
        out.println("  if (value[0] == '+' || value[0] == '-') {");
        out.println("    // boolean options");
        genMatchers(out, lengths, options, true);
        out.println("  } else {");
        out.println("    // non-boolean options");
        genMatchers(out, lengths, options, false);
        out.println("  }");
        out.println("  return false;");
        out.println("}");
    }

    protected static void genMatchers(PrintStream out, Set<Integer> lengths, SortedMap<String, OptionDescriptor> options, boolean isBoolean) throws Exception {
        out.println("    switch (name_len) {");
        for (int len : lengths) {
            boolean printedCase = false;

            // The use of strncmp is required (instead of strcmp) as the option name will not be
            // null terminated for <name>=<value> style options.
            if (len == "PrintFlags".length() && isBoolean) {
                printedCase = true;
                out.println("    case " + len + ":");
                out.printf("      if (strncmp(name, \"PrintFlags\", %d) == 0) {%n", len);
                out.println("        if (value[0] == '+') {");
                out.println("          VMToCompiler::setOption(hotSpotOptionsClass, name_handle, Handle(), '?', Handle(), 0L);");
                out.println("        }");
                out.println("        return true;");
                out.println("      }");
            }
            for (Map.Entry<String, OptionDescriptor> e : options.entrySet()) {
                OptionDescriptor desc = e.getValue();
                if (e.getKey().length() == len && ((desc.getType() == Boolean.class) == isBoolean)) {
                    if (!printedCase) {
                        printedCase = true;
                        out.println("    case " + len + ":");
                    }
                    out.printf("      if (strncmp(name, \"%s\", %d) == 0) {%n", e.getKey(), len);
                    Class<?> declaringClass = desc.getDeclaringClass();
                    out.printf("        Handle option = get_OptionValue(\"L%s;\", \"%s\", \"L%s;\", CHECK_(true));%n", toInternalName(declaringClass), desc.getFieldName(),
                                    toInternalName(getFieldType(desc)));
                    if (isBoolean) {
                        out.println("        VMToCompiler::setOption(hotSpotOptionsClass, name_handle, option, value[0], Handle(), 0L);");
                    } else if (desc.getType() == String.class) {
                        out.println("        Handle stringValue = java_lang_String::create_from_str(value, CHECK_(true));");
                        out.println("        VMToCompiler::setOption(hotSpotOptionsClass, name_handle, option, 's', stringValue, 0L);");
                    } else {
                        char spec = getPrimitiveSpecChar(desc);
                        out.println("        jlong primitiveValue = parse_primitive_option_value('" + spec + "', name_handle, value, CHECK_(true));");
                        out.println("        VMToCompiler::setOption(hotSpotOptionsClass, name_handle, option, '" + spec + "', Handle(), primitiveValue);");
                    }
                    out.println("        return true;");
                    out.println("      }");
                }
            }
        }
        out.println("    }");
    }

    @SuppressWarnings("unchecked")
    static SortedMap<String, OptionDescriptor> getOptions() throws Exception {
        Field field = Class.forName("com.oracle.graal.hotspot.HotSpotOptionsLoader").getDeclaredField("options");
        field.setAccessible(true);
        return (SortedMap<String, OptionDescriptor>) field.get(null);
    }

    private static Class<?> getFieldType(OptionDescriptor desc) throws Exception {
        return desc.getDeclaringClass().getDeclaredField(desc.getFieldName()).getType();
    }

    private static String toInternalName(Class<?> c) {
        return c.getName().replace('.', '/');
    }

    /**
     * @see HotSpotOptions#setOption(String, OptionValue, char, String, long)
     */
    @SuppressWarnings("javadoc")
    private static char getPrimitiveSpecChar(OptionDescriptor desc) {
        if (desc.getType() == Integer.class) {
            return 'i';
        }
        if (desc.getType() == Float.class) {
            return 'f';
        }
        if (desc.getType() == Double.class) {
            return 'd';
        }
        throw GraalInternalError.shouldNotReachHere("Unexpected primitive option type: " + desc.getType().getName());
    }
}