/*
 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/auth/AuthScope.java $
 * $Revision: 652950 $
 * $Date: 2008-05-02 16:49:48 -0700 (Fri, 02 May 2008) $
 *
 * ====================================================================
 *
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.auth;

import java.util.Locale;

import org.apache.http.util.LangUtils;

/** 
 * The class represents an authentication scope consisting of a host name,
 * a port number, a realm name and an authentication scheme name which 
 * {@link Credentials Credentials} apply to.
 * 
 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
 * @author <a href="mailto:adrian@intencha.com">Adrian Sutton</a>
 * 
 * @since 4.0
 */
public class AuthScope {
    
    /** 
     * The <tt>null</tt> value represents any host. In the future versions of 
     * HttpClient the use of this parameter will be discontinued.  
     */
    public static final String ANY_HOST = null;

    /** 
     * The <tt>-1</tt> value represents any port.  
     */
    public static final int ANY_PORT = -1;

    /** 
     * The <tt>null</tt> value represents any realm.  
     */
    public static final String ANY_REALM = null;

    /** 
     * The <tt>null</tt> value represents any authentication scheme.  
     */
    public static final String ANY_SCHEME = null;
    
    /** 
     * Default scope matching any host, port, realm and authentication scheme. 
     * In the future versions of HttpClient the use of this parameter will be 
     * discontinued.  
     */
    public static final AuthScope ANY = new AuthScope(ANY_HOST, ANY_PORT, ANY_REALM, ANY_SCHEME);

    /** The authentication scheme the credentials apply to. */
    private final String scheme;
    
    /** The realm the credentials apply to. */
    private final String realm;
    
    /** The host the credentials apply to. */
    private final String host;
        
    /** The port the credentials apply to. */
    private final int port;
        
    /** Creates a new credentials scope for the given 
     * <tt>host</tt>, <tt>port</tt>, <tt>realm</tt>, and 
     * <tt>authentication scheme</tt>.
     * 
     * @param host the host the credentials apply to. May be set
     *   to <tt>null</tt> if credenticals are applicable to
     *   any host. 
     * @param port the port the credentials apply to. May be set
     *   to negative value if credenticals are applicable to
     *   any port. 
     * @param realm the realm the credentials apply to. May be set 
     *   to <tt>null</tt> if credenticals are applicable to
     *   any realm. 
     * @param scheme the authentication scheme the credentials apply to. 
     *   May be set to <tt>null</tt> if credenticals are applicable to
     *   any authentication scheme. 
     */
    public AuthScope(final String host, int port, 
        final String realm, final String scheme)
    {
        this.host =   (host == null)   ? ANY_HOST: host.toLowerCase(Locale.ENGLISH);
        this.port =   (port < 0)       ? ANY_PORT: port;
        this.realm =  (realm == null)  ? ANY_REALM: realm;
        this.scheme = (scheme == null) ? ANY_SCHEME: scheme.toUpperCase(Locale.ENGLISH);
    }
    
    /** Creates a new credentials scope for the given 
     * <tt>host</tt>, <tt>port</tt>, <tt>realm</tt>, and any
     * authentication scheme.
     * 
     * @param host the host the credentials apply to. May be set
     *   to <tt>null</tt> if credenticals are applicable to
     *   any host. 
     * @param port the port the credentials apply to. May be set
     *   to negative value if credenticals are applicable to
     *   any port. 
     * @param realm the realm the credentials apply to. May be set 
     *   to <tt>null</tt> if credenticals are applicable to
     *   any realm. 
     */
    public AuthScope(final String host, int port, final String realm) {
        this(host, port, realm, ANY_SCHEME);
    }
    
    /** Creates a new credentials scope for the given 
     * <tt>host</tt>, <tt>port</tt>, any realm name, and any
     * authentication scheme.
     * 
     * @param host the host the credentials apply to. May be set
     *   to <tt>null</tt> if credenticals are applicable to
     *   any host. 
     * @param port the port the credentials apply to. May be set
     *   to negative value if credenticals are applicable to
     *   any port. 
     */
    public AuthScope(final String host, int port) {
        this(host, port, ANY_REALM, ANY_SCHEME);
    }
    
    /** 
     * Creates a copy of the given credentials scope.
     */
    public AuthScope(final AuthScope authscope) {
        super();
        if (authscope == null) {
            throw new IllegalArgumentException("Scope may not be null");
        }
        this.host = authscope.getHost();
        this.port = authscope.getPort();
        this.realm = authscope.getRealm();
        this.scheme = authscope.getScheme();
    }
    
    /**
     * @return the host
     */
    public String getHost() {
        return this.host;
    }

    /**
     * @return the port
     */
    public int getPort() {
        return this.port;
    }

    /**
     * @return the realm name
     */
    public String getRealm() {
        return this.realm;
    }

    /**
     * @return the scheme type
     */
    public String getScheme() {
        return this.scheme;
    }

    /**
     * Tests if the authentication scopes match. 
     * 
     * @return the match factor. Negative value signifies no match. 
     *    Non-negative signifies a match. The greater the returned value 
     *    the closer the match.
     */
    public int match(final AuthScope that) {
        int factor = 0;
        if (LangUtils.equals(this.scheme, that.scheme)) {
            factor += 1;
        } else {
            if (this.scheme != ANY_SCHEME && that.scheme != ANY_SCHEME) {
                return -1;
            }
        }
        if (LangUtils.equals(this.realm, that.realm)) {
            factor += 2;
        } else {
            if (this.realm != ANY_REALM && that.realm != ANY_REALM) {
                return -1;
            }
        }
        if (this.port == that.port) {
            factor += 4;
        } else {
            if (this.port != ANY_PORT && that.port != ANY_PORT) {
                return -1;
            }
        }
        if (LangUtils.equals(this.host, that.host)) {
            factor += 8;
        } else {
            if (this.host != ANY_HOST && that.host != ANY_HOST) {
                return -1;
            }
        }
        return factor;
    }

    /**
     * @see java.lang.Object#equals(Object)
     */
    @Override
    public boolean equals(Object o) {
        if (o == null) {
            return false;
        }
        if (o == this) {
            return true;
        }
        if (!(o instanceof AuthScope)) {
            return super.equals(o);
        }
        AuthScope that = (AuthScope) o;
        return 
        LangUtils.equals(this.host, that.host) 
          && this.port == that.port
          && LangUtils.equals(this.realm, that.realm)
          && LangUtils.equals(this.scheme, that.scheme);
    }

    /**
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        StringBuffer buffer = new StringBuffer();
        if (this.scheme != null) {
            buffer.append(this.scheme.toUpperCase(Locale.ENGLISH));
            buffer.append(' ');
        }
        if (this.realm != null) {
            buffer.append('\'');
            buffer.append(this.realm);
            buffer.append('\'');
        } else {
            buffer.append("<any realm>");
        }
        if (this.host != null) {
            buffer.append('@');
            buffer.append(this.host);
            if (this.port >= 0) {
                buffer.append(':');
                buffer.append(this.port);
            }
        }
        return buffer.toString();
    }
    
    /**
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        int hash = LangUtils.HASH_SEED;
        hash = LangUtils.hashCode(hash, this.host);
        hash = LangUtils.hashCode(hash, this.port);
        hash = LangUtils.hashCode(hash, this.realm);
        hash = LangUtils.hashCode(hash, this.scheme);
        return hash;
    }
}