/*
 *  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;

public class AuthState {
    public static final String PREEMPTIVE_AUTH_SCHEME = "basic";

    /** Actual authentication scheme */
    private AuthScheme authScheme = null;

    /** Whether an authetication challenged has been received */
    private boolean authRequested = false;

    /** Whether the authetication challenge has been responsed to */
    private boolean authAttempted = false;

    /** Whether preemtive authentication is attempted */
    private boolean preemptive  = false;

    /**
     * Default constructor.
     *
     */
    public AuthState() {
        super();
    }

    /**
     * Invalidates the authentication state by resetting its parameters.
     */
    public void invalidate() {
        this.authScheme = null;
        this.authRequested = false;
        this.authAttempted = false;
        this.preemptive = false;
    }

    /**
     * Tests whether authenication challenge has been received
     *
     * @return <tt>true</tt> if authenication challenge has been received,
     *  <tt>false</tt> otherwise
     */
    public boolean isAuthRequested() {
        return this.authRequested;
    }

    /**
     * Sets authentication request status
     *
     * @param challengeReceived <tt>true</tt> if authenication has been requested,
     *  <tt>false</tt> otherwise
     */
    public void setAuthRequested(boolean challengeReceived) {
        this.authRequested = challengeReceived;
    }

    /**
     * Tests whether authenication challenge has been responsed to
     *
     * @return <tt>true</tt> if authenication challenge has been responsed to,
     *  <tt>false</tt> otherwise
     */
    public boolean isAuthAttempted() {
        return this.authAttempted;
    }

    /**
     * Sets authentication attempt status
     *
     * @param challengeResponded <tt>true</tt> if authenication has been attempted,
     *  <tt>false</tt> otherwise
     */
    public void setAuthAttempted(boolean challengeResponded) {
        this.authAttempted = challengeResponded;
    }

    /**
     * Preemptively assigns Basic authentication scheme.
     */
    public void setPreemptive() {
        if (!this.preemptive) {
            if (this.authScheme != null) {
                throw new IllegalStateException("Authentication state already initialized");
            }
            this.authScheme = AuthPolicy.getAuthScheme(PREEMPTIVE_AUTH_SCHEME);
            this.preemptive = true;
        }
    }

    /**
     * Tests if preemptive authentication is used.
     *
     * @return <tt>true</tt> if using the default Basic {@link AuthScheme
     * authentication scheme}, <tt>false</tt> otherwise.
     */
    public boolean isPreemptive() {
        return this.preemptive;
    }

    /**
     * Assigns the given {@link AuthScheme authentication scheme}.
     *
     * @param authScheme the {@link AuthScheme authentication scheme}
     */
    public void setAuthScheme(final AuthScheme authScheme) {
        if (authScheme == null) {
            invalidate();
            return;
        }
        if (this.preemptive && !(this.authScheme.getClass().isInstance(authScheme))) {
            this.preemptive = false;
            this.authAttempted = false;
        }
        this.authScheme = authScheme;
    }

    /**
     * Returns the {@link AuthScheme authentication scheme}.
     *
     * @return {@link AuthScheme authentication scheme}
     */
    public AuthScheme getAuthScheme() {
        return authScheme;
    }

    /**
     * Returns the authentication realm.
     *
     * @return the name of the authentication realm
     */
    public String getRealm() {
        if (this.authScheme != null) {
            return this.authScheme.getRealm();
        } else {
            return null;
        }
    }

    public String toString() {
        StringBuffer buffer = new StringBuffer();
        buffer.append("Auth state: auth requested [");
        buffer.append(this.authRequested);
        buffer.append("]; auth attempted [");
        buffer.append(this.authAttempted);
        if (this.authScheme != null) {
            buffer.append("]; auth scheme [");
            buffer.append(this.authScheme.getSchemeName());
            buffer.append("]; realm [");
            buffer.append(this.authScheme.getRealm());
        }
        buffer.append("] preemptive [");
        buffer.append(this.preemptive);
        buffer.append("]");
        return buffer.toString();
    }

}