/*
 * Copyright  2001-2005 The Apache Software Foundation
 *
 *  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.
 *
 */

package org.apache.tools.ant.taskdefs.condition;

import java.util.Locale;
import org.apache.tools.ant.BuildException;

/**
 * Condition that tests the OS type.
 *
 * @since Ant 1.4
 */
public class Os implements Condition {
    private static final String OS_NAME =
        System.getProperty("os.name").toLowerCase(Locale.US);
    private static final String OS_ARCH =
        System.getProperty("os.arch").toLowerCase(Locale.US);
    private static final String OS_VERSION =
        System.getProperty("os.version").toLowerCase(Locale.US);
    private static final String PATH_SEP =
        System.getProperty("path.separator");

    private String family;
    private String name;
    private String version;
    private String arch;

    /**
     * Default constructor
     *
     */
    public Os() {
    }

    /**
     * Constructor that sets the family attribute
     *
     * @param family a String value
     */
    public Os(String family) {
        setFamily(family);
    }

    /**
     * Sets the desired OS family type
     *
     * @param f      The OS family type desired<br />
     *               Possible values:<br />
     *               <ul>
     *               <li>dos</li>
     *               <li>mac</li>
     *               <li>netware</li>
     *               <li>os/2</li>
     *               <li>tandem</li>
     *               <li>unix</li>
     *               <li>windows</li>
     *               <li>win9x</li>
     *               <li>z/os</li>
     *               <li>os/400</li>
     *               </ul>
     */
    public void setFamily(String f) {
        family = f.toLowerCase(Locale.US);
    }

    /**
     * Sets the desired OS name
     *
     * @param name   The OS name
     */
    public void setName(String name) {
        this.name = name.toLowerCase(Locale.US);
    }

    /**
     * Sets the desired OS architecture
     *
     * @param arch   The OS architecture
     */
    public void setArch(String arch) {
        this.arch = arch.toLowerCase(Locale.US);
    }

    /**
     * Sets the desired OS version
     *
     * @param version   The OS version
     */
    public void setVersion(String version) {
        this.version = version.toLowerCase(Locale.US);
    }

    /**
     * Determines if the OS on which Ant is executing matches the type of
     * that set in setFamily.
     * @see Os#setFamily(String)
     */
    public boolean eval() throws BuildException {
        return isOs(family, name, arch, version);
    }

    /**
     * Determines if the OS on which Ant is executing matches the
     * given OS family.
     * @param family the family to check for
     * @return true if the OS matches
     * @since 1.5
     */
    public static boolean isFamily(String family) {
        return isOs(family, null, null, null);
    }

    /**
     * Determines if the OS on which Ant is executing matches the
     * given OS name.
     *
     * @param name the OS name to check for
     * @return true if the OS matches
     * @since 1.7
     */
    public static boolean isName(String name) {
        return isOs(null, name, null, null);
    }

    /**
     * Determines if the OS on which Ant is executing matches the
     * given OS architecture.
     *
     * @param arch the OS architecture to check for
     * @return true if the OS matches
     * @since 1.7
     */
    public static boolean isArch(String arch) {
        return isOs(null, null, arch, null);
    }

    /**
     * Determines if the OS on which Ant is executing matches the
     * given OS version.
     *
     * @param version the OS version to check for
     * @return true if the OS matches
     * @since 1.7
     */
    public static boolean isVersion(String version) {
        return isOs(null, null, null, version);
    }

    /**
     * Determines if the OS on which Ant is executing matches the
     * given OS family, name, architecture and version
     *
     * @param family   The OS family
     * @param name   The OS name
     * @param arch   The OS architecture
     * @param version   The OS version
     * @return true if the OS matches
     * @since 1.7
     */
    public static boolean isOs(String family, String name, String arch,
                               String version) {
        boolean retValue = false;

        if (family != null || name != null || arch != null
            || version != null) {

            boolean isFamily = true;
            boolean isName = true;
            boolean isArch = true;
            boolean isVersion = true;

            if (family != null) {
                if (family.equals("windows")) {
                    isFamily = OS_NAME.indexOf("windows") > -1;
                } else if (family.equals("os/2")) {
                    isFamily = OS_NAME.indexOf("os/2") > -1;
                } else if (family.equals("netware")) {
                    isFamily = OS_NAME.indexOf("netware") > -1;
                } else if (family.equals("dos")) {
                    isFamily = PATH_SEP.equals(";") && !isFamily("netware");
                } else if (family.equals("mac")) {
                    isFamily = OS_NAME.indexOf("mac") > -1;
                } else if (family.equals("tandem")) {
                    isFamily = OS_NAME.indexOf("nonstop_kernel") > -1;
                } else if (family.equals("unix")) {
                    isFamily = PATH_SEP.equals(":")
                        && !isFamily("openvms")
                        && (!isFamily("mac") || OS_NAME.endsWith("x"));
                } else if (family.equals("win9x")) {
                    isFamily = isFamily("windows")
                        && (OS_NAME.indexOf("95") >= 0
                            || OS_NAME.indexOf("98") >= 0
                            || OS_NAME.indexOf("me") >= 0
                            || OS_NAME.indexOf("ce") >= 0);
                } else if (family.equals("z/os")) {
                    isFamily = OS_NAME.indexOf("z/os") > -1
                        || OS_NAME.indexOf("os/390") > -1;
                } else if (family.equals("os/400")) {
                    isFamily = OS_NAME.indexOf("os/400") > -1;
                } else if (family.equals("openvms")) {
                    isFamily = OS_NAME.indexOf("openvms") > -1;
                } else {
                    throw new BuildException(
                        "Don\'t know how to detect os family \""
                        + family + "\"");
                }
            }
            if (name != null) {
                isName = name.equals(OS_NAME);
            }
            if (arch != null) {
                isArch = arch.equals(OS_ARCH);
            }
            if (version != null) {
                isVersion = version.equals(OS_VERSION);
            }
            retValue = isFamily && isName && isArch && isVersion;
        }
        return retValue;
    }
}