/*
 * Copyright 1999-2004 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.cocoon.environment.http;

import org.apache.cocoon.environment.Cookie;

/**
 *
 * Creates a cookie, a small amount of information sent by a servlet to
 * a Web browser, saved by the browser, and later sent back to the server.
 * A cookie's value can uniquely
 * identify a client, so cookies are commonly used for session management.
 *
 * <p>A cookie has a name, a single value, and optional attributes
 * such as a comment, path and domain qualifiers, a maximum age, and a
 * version number. Some Web browsers have bugs in how they handle the
 * optional attributes, so use them sparingly to improve the interoperability
 * of your servlets.
 *
 * <p>The servlet sends cookies to the browser by using the
 * {@link HttpResponse#addCookie(Cookie)} method, which adds
 * fields to HTTP response headers to send cookies to the
 * browser, one at a time. The browser is expected to
 * support 20 cookies for each Web server, 300 cookies total, and
 * may limit cookie size to 4 KB each.
 *
 * <p>The browser returns cookies to the servlet by adding
 * fields to HTTP request headers. Cookies can be retrieved
 * from a request by using the {@link HttpRequest#getCookies()} method.
 * Several cookies might have the same name but different path attributes.
 *
 * <p>Cookies affect the caching of the Web pages that use them.
 * HTTP 1.0 does not cache pages that use cookies created with
 * this class. This class does not support the cache control
 * defined with HTTP 1.1.
 *
 * <p>This class supports both the Version 0 (by Netscape) and Version 1
 * (by RFC 2109) cookie specifications. By default, cookies are
 * created using Version 0 to ensure the best interoperability.
 *
 *
 * @version $Id$
 */
public final class HttpCookie
implements Cookie {

    private javax.servlet.http.Cookie cookie;

    public HttpCookie(String name, String value) {
        this.cookie = new javax.servlet.http.Cookie(name, value);
    }

    public HttpCookie(javax.servlet.http.Cookie cookie) {
        this.cookie = cookie;
    }

    public javax.servlet.http.Cookie getServletCookie() {
        this.checkState();
        return this.cookie;
    }

    /**
     * Constructs a cookie with a specified name and value.
     *
     * <p>The name must conform to RFC 2109. That means it can contain
     * only ASCII alphanumeric characters and cannot contain commas,
     * semicolons, or white space or begin with a $ character. The cookie's
     * name cannot be changed after creation.
     *
     * <p>The value can be anything the server chooses to send. Its
     * value is probably of interest only to the server. The cookie's
     * value can be changed after creation with the
     * <code>setValue</code> method.
     *
     * <p>By default, cookies are created according to the Netscape
     * cookie specification. The version can be changed with the
     * <code>setVersion</code> method.
     *
     *
     * @param name                         a <code>String</code> specifying the name of the cookie
     *
     * @param value                        a <code>String</code> specifying the value of the cookie
     *
     * @throws IllegalArgumentException        if the cookie name contains illegal characters
     *                                        (for example, a comma, space, or semicolon)
     *                                        or it is one of the tokens reserved for use
     *                                        by the cookie protocol
     * @see #setValue(String)
     * @see #setVersion(int)
     *
     */

    public void init(String name, String value) {
        if (this.cookie == null) {
            this.cookie = new javax.servlet.http.Cookie(name, value);
        } else {
            throw new IllegalStateException("Cookie is already initialised");
        }
    }


    private void checkState() {
        if (this.cookie == null) {
            throw new IllegalStateException("Cookie is not initialised");
        }
    }

    /**
     *
     * Specifies a comment that describes a cookie's purpose.
     * The comment is useful if the browser presents the cookie
     * to the user. Comments
     * are not supported by Netscape Version 0 cookies.
     *
     * @param purpose                a <code>String</code> specifying the comment
     *                                to display to the user
     *
     * @see #getComment()
     *
     */

    public void setComment(String purpose) {
        this.checkState();
        this.cookie.setComment(purpose);
    }


    /**
     * Returns the comment describing the purpose of this cookie, or
     * <code>null</code> if the cookie has no comment.
     *
     * @return                        a <code>String</code> containing the comment,
     *                                or <code>null</code> if none
     *
     * @see #setComment(String)
     *
     */

    public String getComment() {
        this.checkState();
        return this.cookie.getComment();
    }


    /**
     *
     * Specifies the domain within which this cookie should be presented.
     *
     * <p>The form of the domain name is specified by RFC 2109. A domain
     * name begins with a dot (<code>.foo.com</code>) and means that
     * the cookie is visible to servers in a specified Domain Name System
     * (DNS) zone (for example, <code>www.foo.com</code>, but not
     * <code>a.b.foo.com</code>). By default, cookies are only returned
     * to the server that sent them.
     *
     *
     * @param pattern                a <code>String</code> containing the domain name
     *                                within which this cookie is visible;
     *                                form is according to RFC 2109
     *
     * @see #getDomain()
     *
     */

    public void setDomain(String pattern) {
        this.checkState();
        this.cookie.setDomain(pattern);
    }


    /**
     * Returns the domain name set for this cookie. The form of
     * the domain name is set by RFC 2109.
     *
     * @return                        a <code>String</code> containing the domain name
     *
     * @see #setDomain(String)
     *
     */

    public String getDomain() {
        this.checkState();
        return this.cookie.getDomain();
    }


    /**
     * Sets the maximum age of the cookie in seconds.
     *
     * <p>A positive value indicates that the cookie will expire
     * after that many seconds have passed. Note that the value is
     * the <i>maximum</i> age when the cookie will expire, not the cookie's
     * current age.
     *
     * <p>A negative value means
     * that the cookie is not stored persistently and will be deleted
     * when the Web browser exits. A zero value causes the cookie
     * to be deleted.
     *
     * @param expiry                an integer specifying the maximum age of the
     *                                 cookie in seconds; if negative, means
     *                                the cookie is not stored; if zero, deletes
     *                                the cookie
     *
     *
     * @see #getMaxAge()
     *
     */

    public void setMaxAge(int expiry) {
        this.checkState();
        this.cookie.setMaxAge(expiry);
    }


    /**
     * Returns the maximum age of the cookie, specified in seconds,
     * By default, <code>-1</code> indicating the cookie will persist
     * until browser shutdown.
     *
     *
     * @return                        an integer specifying the maximum age of the
     *                                cookie in seconds; if negative, means
     *                                the cookie persists until browser shutdown
     *
     *
     * @see #setMaxAge(int)
     *
     */

    public int getMaxAge() {
        this.checkState();
        return this.cookie.getMaxAge();
    }


    /**
     * Specifies a path for the cookie
     * to which the client should return the cookie.
     *
     * <p>The cookie is visible to all the pages in the directory
     * you specify, and all the pages in that directory's subdirectories.
     * A cookie's path must include the servlet that set the cookie,
     * for example, <i>/catalog</i>, which makes the cookie
     * visible to all directories on the server under <i>/catalog</i>.
     *
     * <p>Consult RFC 2109 (available on the Internet) for more
     * information on setting path names for cookies.
     *
     *
     * @param uri                a <code>String</code> specifying a path
     *
     *
     * @see #getPath()
     *
     */

    public void setPath(String uri) {
        this.checkState();
        this.cookie.setPath(uri);
    }


    /**
     * Returns the path on the server
     * to which the browser returns this cookie. The
     * cookie is visible to all subpaths on the server.
     *
     *
     * @return                a <code>String</code> specifying a path that contains
     *                        a servlet name, for example, <i>/catalog</i>
     *
     * @see #setPath(String)
     *
     */

    public String getPath() {
        this.checkState();
        return this.cookie.getPath();
    }


    /**
     * Indicates to the browser whether the cookie should only be sent
     * using a secure protocol, such as HTTPS or SSL.
     *
     * <p>The default value is <code>false</code>.
     *
     * @param flag        if <code>true</code>, sends the cookie from the browser
     *                        to the server using only when using a secure protocol;
     *                        if <code>false</code>, sent on any protocol
     *
     * @see #getSecure()
     *
     */

    public void setSecure(boolean flag) {
        this.checkState();
        this.cookie.setSecure(flag);
    }


    /**
     * Returns <code>true</code> if the browser is sending cookies
     * only over a secure protocol, or <code>false</code> if the
     * browser can send cookies using any protocol.
     *
     * @return                <code>true</code> if the browser can use
     *                        any standard protocol; otherwise, <code>false</code>
     *
     * @see #setSecure(boolean)
     *
     */

    public boolean getSecure() {
        this.checkState();
        return this.cookie.getSecure();
    }


    /**
     * Returns the name of the cookie. The name cannot be changed after
     * creation.
     *
     * @return                a <code>String</code> specifying the cookie's name
     *
     */

    public String getName() {
        this.checkState();
        return this.cookie.getName();
    }


    /**
     *
     * Assigns a new value to a cookie after the cookie is created.
     * If you use a binary value, you may want to use BASE64 encoding.
     *
     * <p>With Version 0 cookies, values should not contain white
     * space, brackets, parentheses, equals signs, commas,
     * double quotes, slashes, question marks, at signs, colons,
     * and semicolons. Empty values may not behave the same way
     * on all browsers.
     *
     * @param newValue                a <code>String</code> specifying the new value
     *
     *
     * @see #getValue()
     * @see Cookie
     *
     */

    public void setValue(String newValue) {
        this.checkState();
        this.cookie.setValue(newValue);
    }


    /**
     * Returns the value of the cookie.
     *
     * @return                        a <code>String</code> containing the cookie's
     *                                present value
     *
     * @see #setValue(String)
     * @see Cookie
     *
     */

    public String getValue() {
        this.checkState();
        return this.cookie.getValue();
    }


    /**
     * Returns the version of the protocol this cookie complies
     * with. Version 1 complies with RFC 2109,
     * and version 0 complies with the original
     * cookie specification drafted by Netscape. Cookies provided
     * by a browser use and identify the browser's cookie version.
     *
     *
     * @return                        0 if the cookie complies with the
     *                                original Netscape specification; 1
     *                                if the cookie complies with RFC 2109
     *
     * @see #setVersion(int)
     *
     */

    public int getVersion() {
        this.checkState();
        return this.cookie.getVersion();
    }


    /**
     * Sets the version of the cookie protocol this cookie complies
     * with. Version 0 complies with the original Netscape cookie
     * specification. Version 1 complies with RFC 2109.
     *
     * <p>Since RFC 2109 is still somewhat new, consider
     * version 1 as experimental; do not use it yet on production sites.
     *
     *
     * @param v                        0 if the cookie should comply with
     *                                the original Netscape specification;
     *                                1 if the cookie should comply with RFC 2109
     *
     * @see #getVersion()
     *
     */

    public void setVersion(int v) {
        this.checkState();
        this.cookie.setVersion(v);
    }


}