/*--------------------------------------------------------------------------
 *  Copyright 2008 Taro L. Saito
 *
 *  Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *--------------------------------------------------------------------------*/
//--------------------------------------
// snappy-java Project
//
// OSInfo.java
// Since: May 20, 2008
//
// $URL$ 
// $Author$
//--------------------------------------
package org.xerial.snappy;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Locale;

/**
 * Provides OS name and architecture name.
 *
 * @author leo
 */
public class OSInfo {
    private static HashMap<String, String> archMapping = new HashMap<String, String>();

    public static final String X86 = "x86";
    public static final String X86_64 = "x86_64";
    public static final String IA64_32 = "ia64_32";
    public static final String IA64 = "ia64";
    public static final String PPC = "ppc";
    public static final String PPC64 = "ppc64";
    public static final String IBMZ = "s390";
    public static final String IBMZ_64 = "s390x";
    public static final String AARCH_64 = "aarch64";
    public static final String RISCV_64 = "riscv64";
    public static final String LOONGARCH_64 = "loongarch64";

    static {
        // x86 mappings
        archMapping.put(X86, X86);
        archMapping.put("i386", X86);
        archMapping.put("i486", X86);
        archMapping.put("i586", X86);
        archMapping.put("i686", X86);
        archMapping.put("pentium", X86);

        // x86_64 mappings
        archMapping.put(X86_64, X86_64);
        archMapping.put("amd64", X86_64);
        archMapping.put("em64t", X86_64);
        archMapping.put("universal", X86_64); // Needed for openjdk7 in Mac

        // Itenium 64-bit mappings
        archMapping.put(IA64, IA64);
        archMapping.put("ia64w", IA64);

        // Itenium 32-bit mappings, usually an HP-UX construct
        archMapping.put(IA64_32, IA64_32);
        archMapping.put("ia64n", IA64_32);

        // PowerPC mappings
        archMapping.put(PPC, PPC);
        archMapping.put("power", PPC);
        archMapping.put("powerpc", PPC);
        archMapping.put("power_pc", PPC);
        archMapping.put("power_rs", PPC);

        // TODO: PowerPC 64bit mappings
        archMapping.put(PPC64, PPC64);
        archMapping.put("power64", PPC64);
        archMapping.put("powerpc64", PPC64);
        archMapping.put("power_pc64", PPC64);
        archMapping.put("power_rs64", PPC64);

        // IBM z mappings
        archMapping.put(IBMZ, IBMZ);

        // IBM z 64-bit mappings
        archMapping.put(IBMZ_64, IBMZ_64);

        // Aarch64 mappings
        archMapping.put(AARCH_64, AARCH_64);

        // RISC-V mappings
        archMapping.put(RISCV_64, RISCV_64);

        // LoongArch64 mappings
        archMapping.put(LOONGARCH_64, LOONGARCH_64);
    }

    public static void main(String[] args) {
        if(args.length >= 1) {
            if("--os".equals(args[0])) {
                System.out.print(getOSName());
                return;
            }
            else if("--arch".equals(args[0])) {
                System.out.print(getArchName());
                return;
            }
        }

        System.out.print(getNativeLibFolderPathForCurrentOS());
    }

    public static String getNativeLibFolderPathForCurrentOS() {
        return getOSName() + "/" + getArchName();
    }

    public static String getOSName() {
        return translateOSNameToFolderName(System.getProperty("os.name"));
    }


    public static boolean isAndroid() {
        return System.getProperty("java.runtime.name", "").toLowerCase().contains("android");
    }

    static String getHardwareName() {
        try {
            Process p = Runtime.getRuntime().exec("uname -m");
            p.waitFor();

            InputStream in = p.getInputStream();
            try {
                int readLen = 0;
                ByteArrayOutputStream b = new ByteArrayOutputStream();
                byte[] buf = new byte[32];
                while((readLen = in.read(buf, 0, buf.length)) >= 0) {
                    b.write(buf, 0, readLen);
                }
                return b.toString();
            }
            finally {
                if(in != null) {
                    in.close();
                }
            }
        }
        catch(Throwable e) {
            System.err.println("Error while running uname -m: " + e.getMessage());
            return "unknown";
        }
    }

    static String resolveArmArchType() {
        if(System.getProperty("os.name").contains("Linux")) {
            String armType = getHardwareName();
            // armType (uname -m) can be armv5t, armv5te, armv5tej, armv5tejl, armv6, armv7, armv7l, i686
            if(armType.startsWith("armv6")) {
                // Raspberry PI
                return "armv6";
            }
            else if(armType.startsWith("armv7")) {
                // Generic
                return "armv7";
            }

            // Java 1.8 introduces a system property to determine armel or armhf
            // http://bugs.java.com/bugdatabase/view_bug.do?bug_id=8005545
            String abi = System.getProperty("sun.arch.abi");
            if(abi != null && abi.startsWith("gnueabihf")) {
                return "armv7";
            }

            // For java7, we stil need to if run some shell commands to determine ABI of JVM
            try {
                // determine if first JVM found uses ARM hard-float ABI
                int exitCode = Runtime.getRuntime().exec("which readelf").waitFor();
                if(exitCode == 0) {
                    String javaHome = System.getProperty("java.home");
                    String[] cmdarray = {"/bin/sh", "-c", "find '" + javaHome +
                        "' -name 'libjvm.so' | head -1 | xargs readelf -A | " +
                        "grep 'Tag_ABI_VFP_args: VFP registers'"};
                    exitCode = Runtime.getRuntime().exec(cmdarray).waitFor();
                    if(exitCode == 0) {
                        return "armv7";
                    }
                }
                else {
                    System.err.println("WARNING! readelf not found. Cannot check if running on an armhf system, " +
                        "armel architecture will be presumed.");
                }
            }
            catch(IOException e) {
                // ignored: fall back to "arm" arch (soft-float ABI)
            }
            catch(InterruptedException e) {
                // ignored: fall back to "arm" arch (soft-float ABI)
            }
        }
        // Use armv5, soft-float ABI
        return "arm";
    }

    public static String getArchName() {
        String osArch = System.getProperty("os.arch");
        // For Android
        if(isAndroid()) {
            return "android-arm";
        }

        if (isX64Musl()) {
            return "x86_64-musl";
        }

        if(osArch.startsWith("arm")) {
            osArch = resolveArmArchType();
        }
        else {
            String lc = osArch.toLowerCase(Locale.US);
            if(archMapping.containsKey(lc))
                return archMapping.get(lc);
        }
        return translateArchNameToFolderName(osArch);
    }

    private static boolean isX64Musl() {
        try {
            return new File("/lib/ld-musl-x86_64.so.1").exists();
        } catch (SecurityException e) {
            return false;
        }
    }

    static String translateOSNameToFolderName(String osName) {
        if(osName.contains("Windows")) {
            return "Windows";
        }
        else if(osName.contains("Mac")) {
            return "Mac";
        }
        else if(osName.contains("Linux")) {
            return "Linux";
        }
        else if(osName.contains("AIX")) {
            return "AIX";
        }
        else {
            return osName.replaceAll("\\W", "");
        }
    }

    static String translateArchNameToFolderName(String archName) {
        return archName.replaceAll("\\W", "");
    }
}