BEGIN LICENSE BLOCK *****
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The contents of this file are subject to the Eclipse Public
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except in compliance with the License. You may obtain a copy of
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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) 2006 Tim Azzopardi 
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
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 * 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) 2006 Tim Azzopardi <tim@tigerfive.com>
 *
 * 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.util;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Properties;

import jnr.posix.util.Platform;
import org.jcodings.Encoding;
import org.jruby.Ruby;
import org.jruby.RubyString;

public class OSEnvironment {

    
Returns the environment as a hash of Ruby strings.
Params:
runtime – /**
     * Returns the environment as a hash of Ruby strings.
     *
     * @param runtime
     */
    public static Map<RubyString, RubyString> environmentVariableMap(Ruby runtime) {
        @SuppressWarnings("unchecked")
        Map<String, String> env = runtime.getInstanceConfig().getEnvironment();
        if ( env != null ) return asMapOfRubyStrings(runtime, env);

        if ( Ruby.isSecurityRestricted() ) return Collections.emptyMap();

        return asMapOfRubyStrings(runtime, System.getenv());
    }

    public Map<RubyString, RubyString> getEnvironmentVariableMap(Ruby runtime) {
        Map envMap = OSEnvironment.environmentVariableMap(runtime);
        return envMap == Collections.EMPTY_MAP ? new HashMap(4) : envMap;
    }

    public static Map<String, String> propertiesToStringMap(Properties properties) {
        Map<String, String> map = new HashMap<String, String>();
        for (Entry<Object, Object> entry : properties.entrySet()) {
            if (entry.getKey() instanceof String && entry.getValue() instanceof String) {
                map.put((String) entry.getKey(), (String) entry.getValue());
            }
        }
        return map;
    }

    
Returns java system properties as a Map.
Params:
runtime – 
Returns:
the java system properties as a Map./**
    * Returns java system properties as a Map<RubyString,RubyString>.
     * @param runtime
     * @return the java system properties as a Map<RubyString,RubyString>.
     */
    public static Map<RubyString, RubyString> systemPropertiesMap(Ruby runtime) {
        if ( Ruby.isSecurityRestricted() ) return Collections.emptyMap();
        return asMapOfRubyStrings(runtime, (Properties) System.getProperties().clone());
    }

    public Map<RubyString, RubyString> getSystemPropertiesMap(Ruby runtime) {
        Map sysMap = OSEnvironment.systemPropertiesMap(runtime);
        return sysMap == Collections.EMPTY_MAP ? new HashMap(4) : sysMap;
    }

    private static Map<RubyString, RubyString> asMapOfRubyStrings(final Ruby runtime, final Map<?, ?> map) {
        @SuppressWarnings("unchecked")
        final Map<RubyString, RubyString> rubyMap = new HashMap(map.size() + 2);
        Encoding keyEncoding = runtime.getEncodingService().getLocaleEncoding();

        // On Windows, map doesn't have corresponding keys for these
        if (Platform.IS_WINDOWS) {
            // these may be null when in a restricted environment (JRUBY-6514)
            String home = SafePropertyAccessor.getProperty("user.home");
            String user = SafePropertyAccessor.getProperty("user.name");
            putRubyKeyValuePair(runtime, rubyMap, "HOME", keyEncoding, home == null ? "/" : home, keyEncoding);
            putRubyKeyValuePair(runtime, rubyMap, "USER", keyEncoding, user == null ? "" : user, keyEncoding);
        }

        for (Map.Entry<?, ?> entry : map.entrySet()) {
            Object val = entry.getKey();

            if ( ! (val instanceof String) ) continue; // Java devs can stuff non-string objects into env
            final String key = (String) val;

            if (Platform.IS_WINDOWS && StringSupport.startsWith(key, '=')) continue;

            val = entry.getValue();
            if ( ! (val instanceof String) ) continue; // Java devs can stuff non-string objects into env

            // Ensure PATH is encoded like filesystem
            Encoding valueEncoding = keyEncoding;
            if ( org.jruby.platform.Platform.IS_WINDOWS ?
                    key.equalsIgnoreCase("PATH") :
                    key.equals("PATH") ) {
                valueEncoding = runtime.getEncodingService().getFileSystemEncoding();
            }

            putRubyKeyValuePair(runtime, rubyMap, key, keyEncoding, (String) val, valueEncoding);
        }

        return rubyMap;
    }

    private static void putRubyKeyValuePair(Ruby runtime,
        final Map<RubyString, RubyString> map,
        String key, Encoding keyEncoding, String value, Encoding valueEncoding) {
        ByteList keyBytes = RubyString.encodeBytelist(key, keyEncoding);
        ByteList valueBytes = RubyString.encodeBytelist(value, valueEncoding);

        RubyString keyString = runtime.newString(keyBytes);
        RubyString valueString = runtime.newString(valueBytes);

        keyString.setFrozen(true);
        keyString.setTaint(true);
        valueString.setFrozen(true);
        valueString.setTaint(true);

        map.put(keyString, valueString);
    }

}