BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
License Version 2.0 (the "License"); you may not use this file
except in compliance with the License. You may obtain a copy of
the License at http://www.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2008 JRuby project
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
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and other provisions required by the GPL or the LGPL. If you do not delete
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END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2008 JRuby project
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby.ext.ffi;

import java.nio.ByteOrder;
import java.util.regex.Pattern;
import org.jruby.Ruby;
import org.jruby.RubyModule;
import org.jruby.anno.JRubyMethod;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.util.SafePropertyAccessor;

/**
 *
 */
public class Platform {

    private static final java.util.Locale LOCALE = java.util.Locale.ENGLISH;

    public static final CPU_TYPE CPU = determineCPU();
    public static final OS_TYPE OS = determineOS();

    private static final int ARCH_DATA_MODEL = determineArchDataModel();

    public static final String NAME = CPU + "-" + OS;
    public static final String LIBPREFIX = OS == OS.WINDOWS ? "" : "lib";
    public static final String LIBSUFFIX = determineLibExt();
    public static final String LIBC = determineLibC();
    
    public static final int BIG_ENDIAN = 4321;
    public static final int LITTLE_ENDIAN = 1234;
    public static final int BYTE_ORDER = ByteOrder.nativeOrder().equals(ByteOrder.BIG_ENDIAN) ? BIG_ENDIAN : LITTLE_ENDIAN;


    protected final int addressSize, longSize;
    private final long addressMask;
    protected final Pattern libPattern;
    private int javaVersionMajor = -1;

    public enum OS_TYPE {
        DARWIN,
        FREEBSD,
        NETBSD,
        OPENBSD,
        DRAGONFLYBSD,
        LINUX,
        SOLARIS,
        AIX,
        WINDOWS,

        UNKNOWN;
        @Override
        public String toString() { return name().toLowerCase(LOCALE); }
    }

    public enum CPU_TYPE {
        I386,
        X86_64,
        POWERPC,
        POWERPC64,
        POWERPC64LE,
        SPARC,
        SPARCV9,
        S390X,
        ARM,
        AARCH64,
        UNKNOWN;
        @Override
        public String toString() { return name().toLowerCase(LOCALE); }
    }

    private static final class SingletonHolder {
        private static final Platform PLATFORM = determinePlatform(determineOS());
    }

    private static final OS_TYPE determineOS() {
        String osName = System.getProperty("os.name").split(" ")[0];
        if (startsWithIgnoreCase(osName, "mac") || startsWithIgnoreCase(osName, "darwin")) {
            return OS_TYPE.DARWIN;
        } else if (startsWithIgnoreCase(osName, "sunos") || startsWithIgnoreCase(osName, "solaris")) {
            return OS_TYPE.SOLARIS;
        }
        for (OS_TYPE os : OS_TYPE.values()) {
            if (startsWithIgnoreCase(osName, os.toString())) {
                return os;
            }
        }
        return OS_TYPE.UNKNOWN;
    }

    private static final Platform determinePlatform(OS_TYPE os) {
        switch (os) {
            case DARWIN:
                return new Darwin();
            case LINUX:
                return new Linux();
            case AIX:
                return new AIX();
            case WINDOWS:
                return new Windows();
            case UNKNOWN:
                return new Unsupported(os);
            default:
                return new Default(os);
        }
    }

    private static final CPU_TYPE determineCPU() {
        String archString = System.getProperty("os.arch").toLowerCase(LOCALE);
        if ("x86".equals(archString) || "i386".equals(archString) || "i86pc".equals(archString)) {
            return CPU.I386;
        } else if ("x86_64".equals(archString) || "amd64".equals(archString)) {
            return CPU.X86_64;
        } else if ("ppc".equals(archString) || "powerpc".equals(archString)) {
            return CPU.POWERPC;
        } else if ("ppc64".equals(archString)) {
            return CPU.POWERPC64;
        } else if ("ppc64le".equals(archString)) {
            return CPU.POWERPC64LE;
        } else if ("sparc".equals(archString)) {
            return CPU.SPARC;
        } else if ("sparcv9".equals(archString)) {
            return CPU.SPARCV9;
        } else if ("s390x".equals(archString)) {
            return CPU.S390X;
        } else if ("arm".equals(archString)) {
            return CPU.ARM;
        } else if ("aarch64".equals(archString)) {
            return CPU.AARCH64;
        } else if ("universal".equals(archString)) {
            // OS X OpenJDK7 builds report "universal" right now
            String bits = SafePropertyAccessor.getProperty("sun.arch.data.model");
            if ("32".equals(bits)) {
                System.setProperty("os.arch", "i386");
                return CPU.I386;
            } else if ("64".equals(bits)) {
                System.setProperty("os.arch", "x86_64");
                return CPU.X86_64;
            }
        }
        return CPU.UNKNOWN;
    }

    private static final String determineLibC() {
        switch (OS) {
            case WINDOWS:
                return "msvcrt.dll";
            case LINUX:
                return "libc.so.6";
            case AIX:
                if (ARCH_DATA_MODEL == 32) {
                    return "libc.a(shr.o)";
                } else {
                    return "libc.a(shr_64.o)";
                }
            default:
                return LIBPREFIX + "c." + LIBSUFFIX;
        }
    }

    private static final String determineLibExt() {
        switch (OS) {
            case WINDOWS:
                return "dll";
            case AIX:
                return "a";
            case DARWIN:
                return "dylib";
            default:
                return "so";
        }
    }

    private static int determineArchDataModel() {
        int dataModel = SafePropertyAccessor.getInt("sun.arch.data.model"); // default: 0
        if (dataModel != 32 && dataModel != 64) {
            switch (CPU) {
                case I386:
                case POWERPC:
                case SPARC:
                    dataModel = 32;
                    break;
                case X86_64:
                case POWERPC64:
                case POWERPC64LE:
                case SPARCV9:
                case S390X:
                case AARCH64:
                    dataModel = 64;
                    break;
                default:
                    dataModel = 0;
            }
        }
        return dataModel;
    }

    protected Platform(OS_TYPE os) {
        addressSize = ARCH_DATA_MODEL;
        addressMask = addressSize == 32 ? 0xffffffffL : 0xffffffffffffffffL;
        longSize = os == OS.WINDOWS ? 32 : addressSize; // Windows is LLP64
        String libpattern;
        switch (os) {
            case WINDOWS:
                libpattern = ".*\\.dll$";
                break;
            case DARWIN:
                libpattern = "lib.*\\.(dylib|jnilib)$";
                break;
            case AIX:
                libpattern = "lib.*\\.a$";
                break;
            default:
                libpattern = "lib.*\\.so.*$";
                break;
        }
        libPattern = Pattern.compile(libpattern);
    }

    
Gets the current Platform
Returns:
The current platform./**
     * Gets the current <tt>Platform</tt>
     *
     * @return The current platform.
     */
    public static final Platform getPlatform() {
        return SingletonHolder.PLATFORM;
    }

    
Gets the current Operating System.
Returns:
A OS value representing the current Operating System./**
     * Gets the current Operating System.
     *
     * @return A <tt>OS</tt> value representing the current Operating System.
     */
    public final OS_TYPE getOS() {
        return OS;
    }

    
Gets the current processor architecture the JVM is running on.
Returns:
A CPU value representing the current processor architecture./**
     * Gets the current processor architecture the JVM is running on.
     *
     * @return A <tt>CPU</tt> value representing the current processor architecture.
     */
    public final CPU_TYPE getCPU() {
        return CPU;
    }

    
Gets the version of the Java Virtual Machine (JVM) jffi is running on.
Returns:
A number representing the java version.  e.g. 8 for java 1.8, 9 for java 9/**
     * Gets the version of the Java Virtual Machine (JVM) jffi is running on.
     *
     * @return A number representing the java version.  e.g. 8 for java 1.8, 9 for java 9
     */
    public final int getJavaMajorVersion() {
        if (javaVersionMajor != -1) return javaVersionMajor;

        int version = 5;
        try {
            String versionString = SafePropertyAccessor.getProperty("java.version");
            if (versionString != null) {
                // remove additional version identifiers, e.g. -ea
                versionString = versionString.split("-|\\+")[0];
                String[] v = versionString.split("\\.");
                if (v[0].equals("1")) {
                    // Pre Java 9, 1.x style
                    version = Integer.valueOf(v[1]);
                } else {
                    // Java 9+, x.y.z style
                    version = Integer.valueOf(v[0]);
                }
            }
        } catch (Exception ex) {
            version = 0;
        }

        return javaVersionMajor = version;
    }
    public final boolean isBSD() {
        return OS == OS.FREEBSD || OS == OS.OPENBSD || OS == OS.NETBSD || OS == OS.DARWIN || OS == OS.DRAGONFLYBSD;
    }
    public final boolean isUnix() {
        return OS != OS.WINDOWS;
    }
    public final boolean isSupported() {
        return OS != OS.UNKNOWN 
                && CPU != CPU.UNKNOWN
                && (addressSize == 32 || addressSize == 64);
    }
    public static void createPlatformModule(Ruby runtime, RubyModule ffi) {
        RubyModule module = ffi.defineModuleUnder("Platform");
        Platform platform = Platform.getPlatform();
        OS_TYPE os = platform.getOS();
        module.defineConstant("ADDRESS_SIZE", runtime.newFixnum(platform.addressSize));
        module.defineConstant("LONG_SIZE", runtime.newFixnum(platform.longSize));
        module.defineConstant("OS", runtime.newString(OS.toString()));
        module.defineConstant("ARCH", runtime.newString(platform.getCPU().toString()));
        module.defineConstant("NAME", runtime.newString(platform.getName()));
        module.defineConstant("IS_WINDOWS", runtime.newBoolean(os == OS.WINDOWS));
        module.defineConstant("IS_BSD", runtime.newBoolean(platform.isBSD()));
        module.defineConstant("IS_FREEBSD", runtime.newBoolean(os == OS.FREEBSD));
        module.defineConstant("IS_DRAGONFLYBSD", runtime.newBoolean(os == OS.DRAGONFLYBSD));
        module.defineConstant("IS_OPENBSD", runtime.newBoolean(os == OS.OPENBSD));
        module.defineConstant("IS_SOLARIS", runtime.newBoolean(os == OS.SOLARIS));
        module.defineConstant("IS_LINUX", runtime.newBoolean(os == OS.LINUX));
        module.defineConstant("IS_MAC", runtime.newBoolean(os == OS.DARWIN));
        module.defineConstant("LIBC", runtime.newString(LIBC));
        module.defineConstant("LIBPREFIX", runtime.newString(LIBPREFIX));
        module.defineConstant("LIBSUFFIX", runtime.newString(LIBSUFFIX));
        module.defineConstant("BYTE_ORDER", runtime.newFixnum(BYTE_ORDER));
        module.defineConstant("BIG_ENDIAN", runtime.newFixnum(BIG_ENDIAN));
        module.defineConstant("LITTLE_ENDIAN", runtime.newFixnum(LITTLE_ENDIAN));
        module.defineAnnotatedMethods(Platform.class);
    }
    @JRubyMethod(name = "windows?", module=true)
    public static IRubyObject windows_p(ThreadContext context, IRubyObject recv) {
        return context.runtime.newBoolean(OS == OS.WINDOWS);
    }
    @JRubyMethod(name = "mac?", module=true)
    public static IRubyObject mac_p(ThreadContext context, IRubyObject recv) {
        return context.runtime.newBoolean(OS == OS.DARWIN);
    }
    @JRubyMethod(name = "unix?", module=true)
    public static IRubyObject unix_p(ThreadContext context, IRubyObject recv) {
        return context.runtime.newBoolean(Platform.getPlatform().isUnix());
    }
    @JRubyMethod(name = "bsd?", module=true)
    public static IRubyObject bsd_p(ThreadContext context, IRubyObject recv) {
        return context.runtime.newBoolean(Platform.getPlatform().isBSD());
    }
    @JRubyMethod(name = "linux?", module=true)
    public static IRubyObject linux_p(ThreadContext context, IRubyObject recv) {
        return context.runtime.newBoolean(OS == OS.LINUX);
    }
    @JRubyMethod(name = "solaris?", module=true)
    public static IRubyObject solaris_p(ThreadContext context, IRubyObject recv) {
        return context.runtime.newBoolean(OS == OS.SOLARIS);
    }
    
An extension over System.getProperty method.
Handles security restrictions, and returns the default
value if the access to the property is restricted.
Params:
property – The system property name.
defValue – The default value.
Returns:
The value of the system property,
        or the default value./**
     * An extension over <code>System.getProperty</code> method.
     * Handles security restrictions, and returns the default
     * value if the access to the property is restricted.
     * @param property The system property name.
     * @param defValue The default value.
     * @return The value of the system property,
     *         or the default value.
     */
    public static String getProperty(String property, String defValue) {
        try {
            return System.getProperty(property, defValue);
        } catch (SecurityException se) {
            return defValue;
        }
    }
    
Gets the size of a C 'long' on the native platform.
Returns:
the size of a long in bits/**
     * Gets the size of a C 'long' on the native platform.
     *
     * @return the size of a long in bits
     */
    public final int longSize() {
        return longSize;
    }

    
Gets the size of a C address/pointer on the native platform.
Returns:
the size of a pointer in bits/**
     * Gets the size of a C address/pointer on the native platform.
     *
     * @return the size of a pointer in bits
     */
    public final int addressSize() {
        return addressSize;
    }
    
    
Gets the 32/64bit mask of a C address/pointer on the native platform.
Returns:
the size of a pointer in bits/**
     * Gets the 32/64bit mask of a C address/pointer on the native platform.
     *
     * @return the size of a pointer in bits
     */
    public final long addressMask() {
        return addressMask;
    }

    
Gets the name of this Platform.
Returns:
The name of this platform./**
     * Gets the name of this <tt>Platform</tt>.
     *
     * @return The name of this platform.
     */
    public String getName() {
        return CPU + "-" + OS;
    }

    public String mapLibraryName(String libName) {
        //
        // A specific version was requested - use as is for search
        //
        if (libPattern.matcher(libName).find()) {
            return libName;
        }
        return System.mapLibraryName(libName);
    }
    private static class Supported extends Platform {
        public Supported(OS_TYPE os) {
            super(os);
        }
    }
    private static class Unsupported extends Platform {
        public Unsupported(OS_TYPE os) {
            super(os);
        }
    }
    private static final class Default extends Platform {

        public Default(OS_TYPE os) {
            super(os);
        }

    }
    
A Platform subclass representing the MacOS system. /**
     * A {@link Platform} subclass representing the MacOS system.
     */
    private static final class Darwin extends Supported {

        public Darwin() {
            super(OS.DARWIN);
        }

        @Override
        public String mapLibraryName(String libName) {
            //
            // A specific version was requested - use as is for search
            //
            if (libPattern.matcher(libName).find()) {
                return libName;
            }
            return "lib" + libName + ".dylib";
        }
    }

    
A Platform subclass representing the Linux operating system. /**
     * A {@link Platform} subclass representing the Linux operating system.
     */
    private static final class Linux extends Supported {

        public Linux() {
            super(OS.LINUX);
        }

        
        @Override
        public String mapLibraryName(String libName) {
            // Older JDK on linux map 'c' to 'libc.so' which doesn't work
            return "c".equals(libName) || "libc.so".equals(libName)
                    ? "libc.so.6" : super.mapLibraryName(libName);
        }
    }

    
A Platform subclass representing the Linux operating system. /**
     * A {@link Platform} subclass representing the Linux operating system.
     */
    private static final class AIX extends Supported {

        public AIX() {
            super(OS.AIX);
        }


        @Override
        public String mapLibraryName(String libName) {
            return "c".equals(libName) || "libc.so".equals(libName)
                    ? LIBC : super.mapLibraryName(libName);
        }
    }

    
A Platform subclass representing the Windows system. /**
     * A {@link Platform} subclass representing the Windows system.
     */
    private static class Windows extends Supported {

        public Windows() {
            super(OS.WINDOWS);
        }
    }

    private static boolean startsWithIgnoreCase(String s1, String s2) {
        return s1.startsWith(s2)
            || s1.toUpperCase(LOCALE).startsWith(s2.toUpperCase(LOCALE))
            || s1.toLowerCase(LOCALE).startsWith(s2.toLowerCase(LOCALE));
    }
}