/*
    * 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.shiro.web.servlet;
  
  import org.apache.shiro.util.StringUtils;
  import org.owasp.encoder.Encode;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.text.DateFormat;
  import java.text.SimpleDateFormat;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.Locale;
  import java.util.TimeZone;
  
  /**
   * Default {@link Cookie Cookie} implementation.  'HttpOnly' is supported out of the box, even on
   * Servlet {@code 2.4} and {@code 2.5} container implementations, using raw header writing logic and not
   * {@link javax.servlet.http.Cookie javax.servlet.http.Cookie} objects (which only has 'HttpOnly' support in Servlet
   * {@code 2.6} specifications and above).
   *
   * @since 1.0
   */
  public class SimpleCookie implements Cookie {
  
      /**
       * {@code -1}, indicating the cookie should expire when the browser closes.
       */
      public static final int DEFAULT_MAX_AGE = -1;
  
      /**
       * {@code -1} indicating that no version property should be set on the cookie.
       */
      public static final int DEFAULT_VERSION = -1;
  
      //These constants are protected on purpose so that the test case can use them
      protected static final String NAME_VALUE_DELIMITER = "=";
      protected static final String ATTRIBUTE_DELIMITER = "; ";
      protected static final long DAY_MILLIS = 86400000; //1 day = 86,400,000 milliseconds
      protected static final String GMT_TIME_ZONE_ID = "GMT";
      protected static final String COOKIE_DATE_FORMAT_STRING = "EEE, dd-MMM-yyyy HH:mm:ss z";
  
      protected static final String COOKIE_HEADER_NAME = "Set-Cookie";
      protected static final String PATH_ATTRIBUTE_NAME = "Path";
      protected static final String EXPIRES_ATTRIBUTE_NAME = "Expires";
      protected static final String MAXAGE_ATTRIBUTE_NAME = "Max-Age";
      protected static final String DOMAIN_ATTRIBUTE_NAME = "Domain";
      protected static final String VERSION_ATTRIBUTE_NAME = "Version";
      protected static final String COMMENT_ATTRIBUTE_NAME = "Comment";
      protected static final String SECURE_ATTRIBUTE_NAME = "Secure";
      protected static final String HTTP_ONLY_ATTRIBUTE_NAME = "HttpOnly";
      protected static final String SAME_SITE_ATTRIBUTE_NAME = "SameSite";
  
      private static final transient Logger log = LoggerFactory.getLogger(SimpleCookie.class);
  
      private String name;
      private String value;
      private String comment;
      private String domain;
      private String path;
      private int maxAge;
      private int version;
      private boolean secure;
      private boolean httpOnly;
      private SameSiteOptions sameSite;
  
      public SimpleCookie() {
          this.maxAge = DEFAULT_MAX_AGE;
          this.version = DEFAULT_VERSION;
          this.httpOnly = true; //most of the cookies ever used by Shiro should be as secure as possible.
          this.sameSite = SameSiteOptions.LAX;
      }
  
      public SimpleCookie(String name) {
          this();
          this.name = name;
      }
  
      public SimpleCookie(Cookie cookie) {
          this.name = cookie.getName();
         this.value = cookie.getValue();
         this.comment = cookie.getComment();
         this.domain = cookie.getDomain();
         this.path = cookie.getPath();
         this.maxAge = Math.max(DEFAULT_MAX_AGE, cookie.getMaxAge());
         this.version = Math.max(DEFAULT_VERSION, cookie.getVersion());
         this.secure = cookie.isSecure();
         this.httpOnly = cookie.isHttpOnly();
         this.sameSite = cookie.getSameSite();
     }
 
     @Override
     public String getName() {
         return name;
     }
 
     @Override
     public void setName(String name) {
         if (!StringUtils.hasText(name)) {
             throw new IllegalArgumentException("Name cannot be null/empty.");
         }
         this.name = name;
     }
 
     @Override
     public String getValue() {
         return value;
     }
 
     @Override
     public void setValue(String value) {
         this.value = value;
     }
 
     @Override
     public String getComment() {
         return comment;
     }
 
     @Override
     public void setComment(String comment) {
         this.comment = comment;
     }
 
     @Override
     public String getDomain() {
         return domain;
     }
 
     @Override
     public void setDomain(String domain) {
         this.domain = domain;
     }
 
     @Override
     public String getPath() {
         return path;
     }
 
     @Override
     public void setPath(String path) {
         this.path = path;
     }
 
     @Override
     public int getMaxAge() {
         return maxAge;
     }
 
     @Override
     public void setMaxAge(int maxAge) {
         this.maxAge = Math.max(DEFAULT_MAX_AGE, maxAge);
     }
 
     @Override
     public int getVersion() {
         return version;
     }
 
     @Override
     public void setVersion(int version) {
         this.version = Math.max(DEFAULT_VERSION, version);
     }
 
     @Override
     public boolean isSecure() {
         return secure;
     }
 
     @Override
     public void setSecure(boolean secure) {
         this.secure = secure;
     }
 
     @Override
     public boolean isHttpOnly() {
         return httpOnly;
     }
 
     @Override
     public void setHttpOnly(boolean httpOnly) {
         this.httpOnly = httpOnly;
     }
 
     @Override
     public SameSiteOptions getSameSite() {
         return sameSite;
     }
 
     @Override
     public void setSameSite(SameSiteOptions sameSite) {
         this.sameSite = sameSite;
         if (this.sameSite == SameSiteOptions.NONE) {
             // do not allow invalid cookies. Only secure cookies are allowed if SameSite is set to NONE.
             setSecure(true);
         }
     }
 
     /**
      * Returns the Cookie's calculated path setting.  If the {@link javax.servlet.http.Cookie#getPath() path} is {@code null}, then the
      * {@code request}'s {@link javax.servlet.http.HttpServletRequest#getContextPath() context path}
      * will be returned. If getContextPath() is the empty string or null then the ROOT_PATH constant is returned.
      *
      * @param request the incoming HttpServletRequest
      * @return the path to be used as the path when the cookie is created or removed
      */
     private String calculatePath(HttpServletRequest request) {
         String path = StringUtils.clean(getPath());
         if (!StringUtils.hasText(path)) {
             path = StringUtils.clean(request.getContextPath());
         }
 
         //fix for http://issues.apache.org/jira/browse/SHIRO-9:
         if (path == null) {
             path = ROOT_PATH;
         }
         log.trace("calculated path: {}", path);
         return path;
     }
 
     @Override
     public void saveTo(HttpServletRequest request, HttpServletResponse response) {
 
         String name = getName();
         String value = getValue();
         String comment = getComment();
         String domain = getDomain();
         String path = calculatePath(request);
         int maxAge = getMaxAge();
         int version = getVersion();
         boolean secure = isSecure();
         boolean httpOnly = isHttpOnly();
         SameSiteOptions sameSite = getSameSite();
 
         addCookieHeader(response, name, value, comment, domain, path, maxAge, version, secure, httpOnly, sameSite);
     }
 
     private void addCookieHeader(HttpServletResponse response, String name, String value, String comment,
                                  String domain, String path, int maxAge, int version,
                                  boolean secure, boolean httpOnly, SameSiteOptions sameSite) {
 
         String headerValue = buildHeaderValue(name, value, comment, domain, path, maxAge, version, secure, httpOnly, sameSite);
         response.addHeader(COOKIE_HEADER_NAME, headerValue);
 
         if (log.isDebugEnabled()) {
             log.debug("Added HttpServletResponse Cookie [{}]", headerValue);
         }
     }
 
     /*
      * This implementation followed the grammar defined here for convenience:
      * <a href="http://github.com/abarth/http-state/blob/master/notes/2009-11-07-Yui-Naruse.txt">Cookie grammar</a>.
      *
      * @return the 'Set-Cookie' header value for this cookie instance.
      */
 
     protected String buildHeaderValue(String name, String value, String comment,
                                       String domain, String path, int maxAge, int version,
                                       boolean secure, boolean httpOnly) {
 
         return buildHeaderValue(name, value, comment, domain, path, maxAge, version, secure, httpOnly, getSameSite());
     }
 
     protected String buildHeaderValue(String name, String value, String comment,
                                       String domain, String path, int maxAge, int version,
                                       boolean secure, boolean httpOnly, SameSiteOptions sameSite) {
 
         if (!StringUtils.hasText(name)) {
             throw new IllegalStateException("Cookie name cannot be null/empty.");
         }
 
         StringBuilder sb = new StringBuilder(name).append(NAME_VALUE_DELIMITER);
 
         if (StringUtils.hasText(value)) {
             sb.append(value);
         }
 
         appendComment(sb, comment);
         appendDomain(sb, domain);
         appendPath(sb, path);
         appendExpires(sb, maxAge);
         appendVersion(sb, version);
         appendSecure(sb, secure);
         appendHttpOnly(sb, httpOnly);
         appendSameSite(sb, sameSite);
 
         return sb.toString();
 
     }
 
     private void appendComment(StringBuilder sb, String comment) {
         if (StringUtils.hasText(comment)) {
             sb.append(ATTRIBUTE_DELIMITER);
             sb.append(COMMENT_ATTRIBUTE_NAME).append(NAME_VALUE_DELIMITER).append(comment);
         }
     }
 
     private void appendDomain(StringBuilder sb, String domain) {
         if (StringUtils.hasText(domain)) {
             sb.append(ATTRIBUTE_DELIMITER);
             sb.append(DOMAIN_ATTRIBUTE_NAME).append(NAME_VALUE_DELIMITER).append(domain);
         }
     }
 
     private void appendPath(StringBuilder sb, String path) {
         if (StringUtils.hasText(path)) {
             sb.append(ATTRIBUTE_DELIMITER);
             sb.append(PATH_ATTRIBUTE_NAME).append(NAME_VALUE_DELIMITER).append(path);
         }
     }
 
     private void appendExpires(StringBuilder sb, int maxAge) {
         // if maxAge is negative, cookie should should expire when browser closes
 	// Don't write the maxAge cookie value if it's negative - at least on Firefox it'll cause the 
 	// cookie to be deleted immediately
         // Write the expires header used by older browsers, but may be unnecessary
         // and it is not by the spec, see http://www.faqs.org/rfcs/rfc2965.html
         // TODO consider completely removing the following 
         if (maxAge >= 0) {
             sb.append(ATTRIBUTE_DELIMITER);
             sb.append(MAXAGE_ATTRIBUTE_NAME).append(NAME_VALUE_DELIMITER).append(maxAge);
             sb.append(ATTRIBUTE_DELIMITER);
             Date expires;
             if (maxAge == 0) {
                 //delete the cookie by specifying a time in the past (1 day ago):
                 expires = new Date(System.currentTimeMillis() - DAY_MILLIS);
             } else {
                 //Value is in seconds.  So take 'now' and add that many seconds, and that's our expiration date:
                 Calendar cal = Calendar.getInstance();
                 cal.add(Calendar.SECOND, maxAge);
                 expires = cal.getTime();
             }
             String formatted = toCookieDate(expires);
             sb.append(EXPIRES_ATTRIBUTE_NAME).append(NAME_VALUE_DELIMITER).append(formatted);
         }
     }
 
     private void appendVersion(StringBuilder sb, int version) {
         if (version > DEFAULT_VERSION) {
             sb.append(ATTRIBUTE_DELIMITER);
             sb.append(VERSION_ATTRIBUTE_NAME).append(NAME_VALUE_DELIMITER).append(version);
         }
     }
 
     private void appendSecure(StringBuilder sb, boolean secure) {
         if (secure) {
             sb.append(ATTRIBUTE_DELIMITER);
             sb.append(SECURE_ATTRIBUTE_NAME); //No value for this attribute
         }
     }
 
     private void appendHttpOnly(StringBuilder sb, boolean httpOnly) {
         if (httpOnly) {
             sb.append(ATTRIBUTE_DELIMITER);
             sb.append(HTTP_ONLY_ATTRIBUTE_NAME); //No value for this attribute
         }
     }
 
     private void appendSameSite(StringBuilder sb, SameSiteOptions sameSite) {
         if (sameSite != null) {
             sb.append(ATTRIBUTE_DELIMITER);
             sb.append(SAME_SITE_ATTRIBUTE_NAME).append(NAME_VALUE_DELIMITER).append(sameSite.toString().toLowerCase(Locale.ENGLISH));
         }
     }
 
     /**
      * Check whether the given {@code cookiePath} matches the {@code requestPath}
      *
      * @param cookiePath
      * @param requestPath
      * @return
      * @see <a href="https://tools.ietf.org/html/rfc6265#section-5.1.4">RFC 6265, Section 5.1.4 "Paths and Path-Match"</a>
      */
     private boolean pathMatches(String cookiePath, String requestPath) {
         if (!requestPath.startsWith(cookiePath)) {
             return false;
         }
 
         return requestPath.length() == cookiePath.length()
             || cookiePath.charAt(cookiePath.length() - 1) == '/'
             || requestPath.charAt(cookiePath.length()) == '/';
     }
 
     /**
      * Formats a date into a cookie date compatible string (Netscape's specification).
      *
      * @param date the date to format
      * @return an HTTP 1.0/1.1 Cookie compatible date string (GMT-based).
      */
     private static String toCookieDate(Date date) {
         TimeZone tz = TimeZone.getTimeZone(GMT_TIME_ZONE_ID);
         DateFormat fmt = new SimpleDateFormat(COOKIE_DATE_FORMAT_STRING, Locale.US);
         fmt.setTimeZone(tz);
         return fmt.format(date);
     }
 
     @Override
     public void removeFrom(HttpServletRequest request, HttpServletResponse response) {
         String name = getName();
         String value = DELETED_COOKIE_VALUE;
         String comment = null; //don't need to add extra size to the response - comments are irrelevant for deletions
         String domain = getDomain();
         String path = calculatePath(request);
         int maxAge = 0; //always zero for deletion
         int version = getVersion();
         boolean secure = isSecure();
         boolean httpOnly = false; //no need to add the extra text, plus the value 'deleteMe' is not sensitive at all
         SameSiteOptions sameSite = getSameSite();
 
         addCookieHeader(response, name, value, comment, domain, path, maxAge, version, secure, httpOnly, sameSite);
 
         log.trace("Removed '{}' cookie by setting maxAge=0", name);
     }
 
     @Override
     public String readValue(HttpServletRequest request, HttpServletResponse ignored) {
         String name = getName();
         String value = null;
         javax.servlet.http.Cookie cookie = getCookie(request, name);
         if (cookie != null) {
             // Validate that the cookie is used at the correct place.
             String path = StringUtils.clean(getPath());
             if (path != null && !pathMatches(path, request.getRequestURI())) {
                 log.warn("Found '{}' cookie at path '{}', but should be only used for '{}'", 
                 		new Object[] { name, Encode.forHtml(request.getRequestURI()), path});
             } else {
                 value = cookie.getValue();
                 log.debug("Found '{}' cookie value [{}]", name, Encode.forHtml(value));
             }
         } else {
             log.trace("No '{}' cookie value", name);
         }
 
         return value;
     }
 
     /**
      * Returns the cookie with the given name from the request or {@code null} if no cookie
      * with that name could be found.
      *
      * @param request    the current executing http request.
      * @param cookieName the name of the cookie to find and return.
      * @return the cookie with the given name from the request or {@code null} if no cookie
      *         with that name could be found.
      */
     private static javax.servlet.http.Cookie getCookie(HttpServletRequest request, String cookieName) {
         javax.servlet.http.Cookie cookies[] = request.getCookies();
         if (cookies != null) {
             for (javax.servlet.http.Cookie cookie : cookies) {
                 if (cookie.getName().equals(cookieName)) {
                     return cookie;
                 }
             }
         }
         return null;
     }
 }