/*

 * Copyright (c) 2013, 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.

 *

 * 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 jdk.test.lib;

import java.io.File;

import java.io.IOException;

import java.io.RandomAccessFile;

import java.util.Arrays;

import java.util.List;

import java.util.Objects;

import java.util.regex.Pattern;

import java.util.stream.Collectors;

public class Platform {

    public  static final String vmName      = System.getProperty("java.vm.name");

    public  static final String vmInfo      = System.getProperty("java.vm.info");

    private static final String osVersion   = System.getProperty("os.version");

    private static       String[] osVersionTokens;

    private static       int osVersionMajor = -1;

    private static       int osVersionMinor = -1;

    private static final String osName      = System.getProperty("os.name");

    private static final String dataModel   = System.getProperty("sun.arch.data.model");

    private static final String vmVersion   = System.getProperty("java.vm.version");

    private static final String jdkDebug    = System.getProperty("jdk.debug");

    private static final String osArch      = System.getProperty("os.arch");

    private static final String userName    = System.getProperty("user.name");

    private static final String compiler    = System.getProperty("sun.management.compiler");

    public static boolean isClient() {

        return vmName.endsWith(" Client VM");

    }

    public static boolean isServer() {

        return vmName.endsWith(" Server VM");

    }

    public static boolean isGraal() {

        return vmName.endsWith(" Graal VM");

    }

    public static boolean isZero() {

        return vmName.endsWith(" Zero VM");

    }

    public static boolean isMinimal() {

        return vmName.endsWith(" Minimal VM");

    }

    public static boolean isEmbedded() {

        return vmName.contains("Embedded");

    }

    public static boolean isEmulatedClient() {

        return vmInfo.contains(" emulated-client");

    }

    public static boolean isTieredSupported() {

        return compiler.contains("Tiered Compilers");

    }

    public static boolean isInt() {

        return vmInfo.contains("interpreted");

    }

    public static boolean isMixed() {

        return vmInfo.contains("mixed");

    }

    public static boolean isComp() {

        return vmInfo.contains("compiled");

    }

    public static boolean is32bit() {

        return dataModel.equals("32");

    }

    public static boolean is64bit() {

        return dataModel.equals("64");

    }

    public static boolean isAix() {

        return isOs("aix");

    }

    public static boolean isLinux() {

        return isOs("linux");

    }

    public static boolean isOSX() {

        return isOs("mac");

    }

    public static boolean isSolaris() {

        return isOs("sunos");

    }

    public static boolean isWindows() {

        return isOs("win");

    }

    private static boolean isOs(String osname) {

        return osName.toLowerCase().startsWith(osname.toLowerCase());

    }

    public static String getOsName() {

        return osName;

    }

    // Os version support.

    private static void init_version() {

        osVersionTokens = osVersion.split("\\.");

        try {

            if (osVersionTokens.length > 0) {

                osVersionMajor = Integer.parseInt(osVersionTokens[0]);

                if (osVersionTokens.length > 1) {

                    osVersionMinor = Integer.parseInt(osVersionTokens[1]);

                }

            }

        } catch (NumberFormatException e) {

            osVersionMajor = osVersionMinor = 0;

        }

    }

    public static String getOsVersion() {

        return osVersion;

    }

    // Returns major version number from os.version system property.

    // E.g. 5 on Solaris 10 and 3 on SLES 11.3 (for the linux kernel version).

    public static int getOsVersionMajor() {

        if (osVersionMajor == -1) init_version();

        return osVersionMajor;

    }

    // Returns minor version number from os.version system property.

    // E.g. 10 on Solaris 10 and 0 on SLES 11.3 (for the linux kernel version).

    public static int getOsVersionMinor() {

        if (osVersionMinor == -1) init_version();

        return osVersionMinor;

    }

    /**

     * Compares the platform version with the supplied version. The

     * version must be of the form a[.b[.c[.d...]]] where a, b, c, d, ...

     * are decimal integers.

     *

     * @throws NullPointerException if the parameter is null

     * @throws NumberFormatException if there is an error parsing either

     *         version as split into component strings

     * @return -1, 0, or 1 according to whether the platform version is

     *         less than, equal to, or greater than the supplied version

     */

    public static int compareOsVersion(String version) {

        if (osVersionTokens == null) init_version();

        Objects.requireNonNull(version);

        List<Integer> s1 = Arrays

            .stream(osVersionTokens)

            .map(Integer::valueOf)

            .collect(Collectors.toList());

        List<Integer> s2 = Arrays

            .stream(version.split("\\."))

            .map(Integer::valueOf)

            .collect(Collectors.toList());

        int count = Math.max(s1.size(), s2.size());

        for (int i = 0; i < count; i++) {

            int i1 = i < s1.size() ? s1.get(i) : 0;

            int i2 = i < s2.size() ? s2.get(i) : 0;

            if (i1 > i2) {

                return 1;

            } else if (i2 > i1) {

                return -1;

            }

        }

        return 0;

    }

    public static boolean isDebugBuild() {

        return (jdkDebug.toLowerCase().contains("debug"));

    }

    public static boolean isSlowDebugBuild() {

        return (jdkDebug.toLowerCase().equals("slowdebug"));

    }

    public static boolean isFastDebugBuild() {

        return (jdkDebug.toLowerCase().equals("fastdebug"));

    }

    public static String getVMVersion() {

        return vmVersion;

    }

    public static boolean isAArch64() {

        return isArch("aarch64");

    }

    public static boolean isARM() {

        return isArch("arm.*");

    }

    public static boolean isPPC() {

        return isArch("ppc.*");

    }

    // Returns true for IBM z System running linux.

    public static boolean isS390x() {

        return isArch("s390.*") || isArch("s/390.*") || isArch("zArch_64");

    }

    // Returns true for sparc and sparcv9.

    public static boolean isSparc() {

        return isArch("sparc.*");

    }

    public static boolean isX64() {

        // On OSX it's 'x86_64' and on other (Linux, Windows and Solaris) platforms it's 'amd64'

        return isArch("(amd64)|(x86_64)");

    }

    public static boolean isX86() {

        // On Linux it's 'i386', Windows 'x86' without '_64' suffix.

        return isArch("(i386)|(x86(?!_64))");

    }

    public static String getOsArch() {

        return osArch;

    }

    /**

     */

        if (isAix()) {

            return false; // SA not implemented.

        } else if (isLinux()) {

            if (isS390x()) {

                return false; // SA not implemented.

            }

            return canPtraceAttachLinux();

        } else if (isOSX()) {

            return canAttachOSX();

        } else {

            // Other platforms expected to work:

            return true;

        }

    }

    /**

     * On Linux, first check the SELinux boolean "deny_ptrace" and return false

     * as we expect to be denied if that is "1".  Then expect permission to attach

     * if we are root, so return true.  Then return false for an expected denial

     * if "ptrace_scope" is 1, and true otherwise.

     */

    private static boolean canPtraceAttachLinux() throws IOException {

        // SELinux deny_ptrace:

        File deny_ptrace = new File("/sys/fs/selinux/booleans/deny_ptrace");

        if (deny_ptrace.exists()) {

            try (RandomAccessFile file = new RandomAccessFile(deny_ptrace, "r")) {

                if (file.readByte() != '0') {

                    return false;

                }

            }

        }

        // YAMA enhanced security ptrace_scope:

        // 0 - a process can PTRACE_ATTACH to any other process running under the same uid

        // 1 - restricted ptrace: a process must be a children of the inferior or user is root

        // 2 - only processes with CAP_SYS_PTRACE may use ptrace or user is root

        // 3 - no attach: no processes may use ptrace with PTRACE_ATTACH

        File ptrace_scope = new File("/proc/sys/kernel/yama/ptrace_scope");

        if (ptrace_scope.exists()) {

            try (RandomAccessFile file = new RandomAccessFile(ptrace_scope, "r")) {

                byte yama_scope = file.readByte();

                if (yama_scope == '3') {

                    return false;

                }

                if (!userName.equals("root") && yama_scope != '0') {

                    return false;

                }

            }

        }

        // Otherwise expect to be permitted:

        return true;

    }

    /**

     * On OSX, expect permission to attach only if we are root.

     */

    private static boolean canAttachOSX() {

        return userName.equals("root");

    }

    private static boolean isArch(String archnameRE) {

        return Pattern.compile(archnameRE, Pattern.CASE_INSENSITIVE)

                      .matcher(osArch)

                      .matches();

    }

    /**

     * Returns file extension of shared library, e.g. "so" on linux, "dll" on windows.

     * @return file extension

     */

    public static String sharedLibraryExt() {

        if (isWindows()) {

            return "dll";

        } else if (isOSX()) {

            return "dylib";

        } else {

            return "so";

        }

    }

    /*

     * This should match the #if condition in ClassListParser::load_class_from_source().

     */

    public static boolean areCustomLoadersSupportedForCDS() {

        boolean isLinux = Platform.isLinux();

        boolean is64 = Platform.is64bit();

        boolean isSolaris = Platform.isSolaris();

        return (is64 && (isLinux || isSolaris));

    }

}