/*
 * Copyright (c) 2008, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.sun.servicetag;

// This class is a copy of the com.sun.scn.servicetags.LinuxSystemEnvironment
// class from the Sun Connection source.
//
// The Service Tags team maintains the latest version of the implementation
// for system environment data collection.  JDK will include a copy of
// the most recent released version for a JDK release. We rename
// the package to com.sun.servicetag so that the Sun Connection
// product always uses the latest version from the com.sun.scn.servicetags
// package. JDK and users of the com.sun.servicetag API
// (e.g. NetBeans and SunStudio) will use the version in JDK.
//
// So we keep this class in src/share/classes instead of src/<os>/classes.

import java.io.*;

/**
 * Linux implementation of the SystemEnvironment class.
 */
class LinuxSystemEnvironment extends SystemEnvironment {
    LinuxSystemEnvironment() {
        setHostId(getLinuxHostId());
        setSystemModel(getCommandOutput("/bin/uname", "-i"));
        setSystemManufacturer(getLinuxSystemManufacturer());
        setCpuManufacturer(getLinuxCpuManufacturer());
        setSerialNumber(getLinuxSN());
    }
    private String dmiInfo = null;

    private static final int SN  = 1;
    private static final int SYS = 2;
    private static final int CPU = 3;

    private String getLinuxHostId() {
        String output = getCommandOutput("/usr/bin/hostid");
        // trim off the leading 0x
        if (output.startsWith("0x")) {
            output = output.substring(2);
        }
        return output;
    }

    /**
     * Tries to obtain and return the cpu manufacturer.
     * @return The cpu manufacturer (an empty string if not found or an error occurred)
     */
    private String getLinuxCpuManufacturer() {
        String tmp = getLinuxPSNInfo(CPU);
        if (tmp.length() > 0) {
            return tmp;
        }

        String contents = getFileContent("/proc/cpuinfo");
        for (String line : contents.split("\n")) {
            if (line.contains("vendor_id")) {
                String[] ss = line.split(":", 2);
                if (ss.length > 1) {
                    return ss[1].trim();
                }
            }
        }

        // returns an empty string if it can't be found or an error happened
        return getLinuxDMIInfo("dmi type 4", "manufacturer");
    }


    /**
     * Tries to obtain and return the system manufacturer.
     * @return The system manufacturer (an empty string if not found or an error occurred)
     */
    private String getLinuxSystemManufacturer() {
        String tmp = getLinuxPSNInfo(SYS);
        if (tmp.length() > 0) {
            return tmp;
        }

        // returns an empty string if it can't be found or an error happened
        return getLinuxDMIInfo("dmi type 1", "manufacturer");
    }

    /**
     * Tries to obtain and return the serial number of the system.
     * @return The serial number (an empty string if not found or an error occurred)
     */
    private String getLinuxSN() {
        String tmp = getLinuxPSNInfo(SN);
        if (tmp.length() > 0) {
            return tmp;
        }

        // returns an empty string if it can't be found or an error happened
        return getLinuxDMIInfo("dmi type 1", "serial number");
    }

    private String getLinuxPSNInfo(int target) {
        // try to read from the psn file if it exists
        String contents = getFileContent("/var/run/psn");
        String[] ss = contents.split("\n");
        if (target <= ss.length) {
            return ss[target-1];
        }

        // default case is to return ""
        return "";
    }

    // reads from dmidecode with the given type and target
    // returns an empty string if nothing was found or an error occurred
    //
    // Sample output segment:
    // Handle 0x0001
    //         DMI type 1, 25 bytes.
    //         System Information
    //                 Manufacturer: System manufacturer
    //                 Product Name: System Product Name
    //                 Version: System Version
    //                 Serial Number: System Serial Number
    //                 UUID: 3091D719-B25B-D911-959D-6D1B12C7686E
    //                 Wake-up Type: Power Switch

    private synchronized String getLinuxDMIInfo(String dmiType, String target) {
        // only try to get dmidecode information once, after that, we can
        // reuse the output
        if (dmiInfo == null) {
            Thread dmidecodeThread = new Thread() {
                public void run() {
                    dmiInfo = getCommandOutput("/usr/sbin/dmidecode");
                }
            };
            dmidecodeThread.start();

            try {
                dmidecodeThread.join(2000);
                if (dmidecodeThread.isAlive()) {
                    dmidecodeThread.interrupt();
                    dmiInfo = "";
                }
            } catch (InterruptedException ie) {
                dmidecodeThread.interrupt();
            }
        }

        if (dmiInfo.length() == 0) {
            return "";
        }
        boolean dmiFlag = false;
        for (String s : dmiInfo.split("\n")) {
            String line = s.toLowerCase();
            if (dmiFlag) {
                if (line.contains(target)) {
                    String key = target + ":";
                    int indx = line.indexOf(key) + key.length();
                    if (line.contains(key) && indx < line.length()) {
                        return line.substring(indx).trim();
                    }
                    String[] ss = line.split(":");
                    return ss[ss.length-1];
                }
            } else if (line.contains(dmiType)) {
                dmiFlag = true;
            }
        }
        return "";
    }

}