/*
 *  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.
 */

package org.apache.ahc.auth;

import org.apache.ahc.util.LangUtils;

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 String scheme = null;

    /**
     * The realm the credentials apply to.
     */
    private String realm = null;

    /**
     * The host the credentials apply to.
     */
    private String host = null;

    /**
     * The port the credentials apply to.
     */
    private int port = -1;

    /**
     * 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();
        this.port = (port < 0) ? ANY_PORT : port;
        this.realm = (realm == null) ? ANY_REALM : realm;
        this.scheme = (scheme == null) ? ANY_SCHEME : scheme.toUpperCase();
        ;
    }

    /**
     * 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;
    }

    /**
     * Determines if the given parameters are equal.
     *
     * @param p1 the parameter
     * @param p2 the other parameter
     * @return boolean true if the parameters are equal, otherwise false.
     */
    private static boolean paramsEqual(final String p1, final String p2) {
        if (p1 == null) {
            return p1 == p2;
        } else {
            return p1.equals(p2);
        }
    }

    /**
     * Determines if the given parameters are equal.
     *
     * @param p1 the parameter
     * @param p2 the other parameter
     * @return boolean true if the parameters are equal, otherwise false.
     */
    private static boolean paramsEqual(int p1, int p2) {
        return p1 == p2;
    }

    /**
     * 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 (paramsEqual(this.scheme, that.scheme)) {
            factor += 1;
        } else {
            if (this.scheme != ANY_SCHEME && that.scheme != ANY_SCHEME) {
                return -1;
            }
        }
        if (paramsEqual(this.realm, that.realm)) {
            factor += 2;
        } else {
            if (this.realm != ANY_REALM && that.realm != ANY_REALM) {
                return -1;
            }
        }
        if (paramsEqual(this.port, that.port)) {
            factor += 4;
        } else {
            if (this.port != ANY_PORT && that.port != ANY_PORT) {
                return -1;
            }
        }
        if (paramsEqual(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)
     */
    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
            paramsEqual(this.host, that.host)
                && paramsEqual(this.port, that.port)
                && paramsEqual(this.realm, that.realm)
                && paramsEqual(this.scheme, that.scheme);
    }

    /**
     * @see java.lang.Object#toString()
     */
    public String toString() {
        StringBuffer buffer = new StringBuffer();
        if (this.scheme != null) {
            buffer.append(this.scheme.toUpperCase());
            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()
     */
    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;
    }
}