/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project 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:
    *
    *   https://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 io.netty.handler.codec.http;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufUtil;
  import io.netty.util.AsciiString;
  import io.netty.util.CharsetUtil;
  import io.netty.util.internal.ObjectUtil;
  
  import static io.netty.handler.codec.http.HttpConstants.SP;
  import static io.netty.util.ByteProcessor.FIND_ASCII_SPACE;
  import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
  import static java.lang.Integer.parseInt;
  
  /**
   * The response code and its description of HTTP or its derived protocols, such as
   * <a href="https://en.wikipedia.org/wiki/Real_Time_Streaming_Protocol">RTSP</a> and
   * <a href="https://en.wikipedia.org/wiki/Internet_Content_Adaptation_Protocol">ICAP</a>.
   */
  public class HttpResponseStatus implements Comparable<HttpResponseStatus> {
  
      /**
       * 100 Continue
       */
      public static final HttpResponseStatus CONTINUE = newStatus(100, "Continue");
  
      /**
       * 101 Switching Protocols
       */
      public static final HttpResponseStatus SWITCHING_PROTOCOLS = newStatus(101, "Switching Protocols");
  
      /**
       * 102 Processing (WebDAV, RFC2518)
       */
      public static final HttpResponseStatus PROCESSING = newStatus(102, "Processing");
  
      /**
       * 103 Early Hints (RFC 8297)
       */
      public static final HttpResponseStatus EARLY_HINTS = newStatus(103, "Early Hints");
  
      /**
       * 200 OK
       */
      public static final HttpResponseStatus OK = newStatus(200, "OK");
  
      /**
       * 201 Created
       */
      public static final HttpResponseStatus CREATED = newStatus(201, "Created");
  
      /**
       * 202 Accepted
       */
      public static final HttpResponseStatus ACCEPTED = newStatus(202, "Accepted");
  
      /**
       * 203 Non-Authoritative Information (since HTTP/1.1)
       */
      public static final HttpResponseStatus NON_AUTHORITATIVE_INFORMATION =
              newStatus(203, "Non-Authoritative Information");
  
      /**
       * 204 No Content
       */
      public static final HttpResponseStatus NO_CONTENT = newStatus(204, "No Content");
  
      /**
       * 205 Reset Content
       */
      public static final HttpResponseStatus RESET_CONTENT = newStatus(205, "Reset Content");
  
      /**
       * 206 Partial Content
       */
      public static final HttpResponseStatus PARTIAL_CONTENT = newStatus(206, "Partial Content");
  
      /**
       * 207 Multi-Status (WebDAV, RFC2518)
       */
      public static final HttpResponseStatus MULTI_STATUS = newStatus(207, "Multi-Status");
  
      /**
       * 300 Multiple Choices
       */
     public static final HttpResponseStatus MULTIPLE_CHOICES = newStatus(300, "Multiple Choices");
 
     /**
      * 301 Moved Permanently
      */
     public static final HttpResponseStatus MOVED_PERMANENTLY = newStatus(301, "Moved Permanently");
 
     /**
      * 302 Found
      */
     public static final HttpResponseStatus FOUND = newStatus(302, "Found");
 
     /**
      * 303 See Other (since HTTP/1.1)
      */
     public static final HttpResponseStatus SEE_OTHER = newStatus(303, "See Other");
 
     /**
      * 304 Not Modified
      */
     public static final HttpResponseStatus NOT_MODIFIED = newStatus(304, "Not Modified");
 
     /**
      * 305 Use Proxy (since HTTP/1.1)
      */
     public static final HttpResponseStatus USE_PROXY = newStatus(305, "Use Proxy");
 
     /**
      * 307 Temporary Redirect (since HTTP/1.1)
      */
     public static final HttpResponseStatus TEMPORARY_REDIRECT = newStatus(307, "Temporary Redirect");
 
     /**
      * 308 Permanent Redirect (RFC7538)
      */
     public static final HttpResponseStatus PERMANENT_REDIRECT = newStatus(308, "Permanent Redirect");
 
     /**
      * 400 Bad Request
      */
     public static final HttpResponseStatus BAD_REQUEST = newStatus(400, "Bad Request");
 
     /**
      * 401 Unauthorized
      */
     public static final HttpResponseStatus UNAUTHORIZED = newStatus(401, "Unauthorized");
 
     /**
      * 402 Payment Required
      */
     public static final HttpResponseStatus PAYMENT_REQUIRED = newStatus(402, "Payment Required");
 
     /**
      * 403 Forbidden
      */
     public static final HttpResponseStatus FORBIDDEN = newStatus(403, "Forbidden");
 
     /**
      * 404 Not Found
      */
     public static final HttpResponseStatus NOT_FOUND = newStatus(404, "Not Found");
 
     /**
      * 405 Method Not Allowed
      */
     public static final HttpResponseStatus METHOD_NOT_ALLOWED = newStatus(405, "Method Not Allowed");
 
     /**
      * 406 Not Acceptable
      */
     public static final HttpResponseStatus NOT_ACCEPTABLE = newStatus(406, "Not Acceptable");
 
     /**
      * 407 Proxy Authentication Required
      */
     public static final HttpResponseStatus PROXY_AUTHENTICATION_REQUIRED =
             newStatus(407, "Proxy Authentication Required");
 
     /**
      * 408 Request Timeout
      */
     public static final HttpResponseStatus REQUEST_TIMEOUT = newStatus(408, "Request Timeout");
 
     /**
      * 409 Conflict
      */
     public static final HttpResponseStatus CONFLICT = newStatus(409, "Conflict");
 
     /**
      * 410 Gone
      */
     public static final HttpResponseStatus GONE = newStatus(410, "Gone");
 
     /**
      * 411 Length Required
      */
     public static final HttpResponseStatus LENGTH_REQUIRED = newStatus(411, "Length Required");
 
     /**
      * 412 Precondition Failed
      */
     public static final HttpResponseStatus PRECONDITION_FAILED = newStatus(412, "Precondition Failed");
 
     /**
      * 413 Request Entity Too Large
      */
     public static final HttpResponseStatus REQUEST_ENTITY_TOO_LARGE =
             newStatus(413, "Request Entity Too Large");
 
     /**
      * 414 Request-URI Too Long
      */
     public static final HttpResponseStatus REQUEST_URI_TOO_LONG = newStatus(414, "Request-URI Too Long");
 
     /**
      * 415 Unsupported Media Type
      */
     public static final HttpResponseStatus UNSUPPORTED_MEDIA_TYPE = newStatus(415, "Unsupported Media Type");
 
     /**
      * 416 Requested Range Not Satisfiable
      */
     public static final HttpResponseStatus REQUESTED_RANGE_NOT_SATISFIABLE =
             newStatus(416, "Requested Range Not Satisfiable");
 
     /**
      * 417 Expectation Failed
      */
     public static final HttpResponseStatus EXPECTATION_FAILED = newStatus(417, "Expectation Failed");
 
     /**
      * 421 Misdirected Request
      *
      * @see <a href="https://tools.ietf.org/html/rfc7540#section-9.1.2">421 (Misdirected Request) Status Code</a>
      */
     public static final HttpResponseStatus MISDIRECTED_REQUEST = newStatus(421, "Misdirected Request");
 
     /**
      * 422 Unprocessable Entity (WebDAV, RFC4918)
      */
     public static final HttpResponseStatus UNPROCESSABLE_ENTITY = newStatus(422, "Unprocessable Entity");
 
     /**
      * 423 Locked (WebDAV, RFC4918)
      */
     public static final HttpResponseStatus LOCKED = newStatus(423, "Locked");
 
     /**
      * 424 Failed Dependency (WebDAV, RFC4918)
      */
     public static final HttpResponseStatus FAILED_DEPENDENCY = newStatus(424, "Failed Dependency");
 
     /**
      * 425 Unordered Collection (WebDAV, RFC3648)
      */
     public static final HttpResponseStatus UNORDERED_COLLECTION = newStatus(425, "Unordered Collection");
 
     /**
      * 426 Upgrade Required (RFC2817)
      */
     public static final HttpResponseStatus UPGRADE_REQUIRED = newStatus(426, "Upgrade Required");
 
     /**
      * 428 Precondition Required (RFC6585)
      */
     public static final HttpResponseStatus PRECONDITION_REQUIRED = newStatus(428, "Precondition Required");
 
     /**
      * 429 Too Many Requests (RFC6585)
      */
     public static final HttpResponseStatus TOO_MANY_REQUESTS = newStatus(429, "Too Many Requests");
 
     /**
      * 431 Request Header Fields Too Large (RFC6585)
      */
     public static final HttpResponseStatus REQUEST_HEADER_FIELDS_TOO_LARGE =
             newStatus(431, "Request Header Fields Too Large");
 
     /**
      * 500 Internal Server Error
      */
     public static final HttpResponseStatus INTERNAL_SERVER_ERROR = newStatus(500, "Internal Server Error");
 
     /**
      * 501 Not Implemented
      */
     public static final HttpResponseStatus NOT_IMPLEMENTED = newStatus(501, "Not Implemented");
 
     /**
      * 502 Bad Gateway
      */
     public static final HttpResponseStatus BAD_GATEWAY = newStatus(502, "Bad Gateway");
 
     /**
      * 503 Service Unavailable
      */
     public static final HttpResponseStatus SERVICE_UNAVAILABLE = newStatus(503, "Service Unavailable");
 
     /**
      * 504 Gateway Timeout
      */
     public static final HttpResponseStatus GATEWAY_TIMEOUT = newStatus(504, "Gateway Timeout");
 
     /**
      * 505 HTTP Version Not Supported
      */
     public static final HttpResponseStatus HTTP_VERSION_NOT_SUPPORTED =
             newStatus(505, "HTTP Version Not Supported");
 
     /**
      * 506 Variant Also Negotiates (RFC2295)
      */
     public static final HttpResponseStatus VARIANT_ALSO_NEGOTIATES = newStatus(506, "Variant Also Negotiates");
 
     /**
      * 507 Insufficient Storage (WebDAV, RFC4918)
      */
     public static final HttpResponseStatus INSUFFICIENT_STORAGE = newStatus(507, "Insufficient Storage");
 
     /**
      * 510 Not Extended (RFC2774)
      */
     public static final HttpResponseStatus NOT_EXTENDED = newStatus(510, "Not Extended");
 
     /**
      * 511 Network Authentication Required (RFC6585)
      */
     public static final HttpResponseStatus NETWORK_AUTHENTICATION_REQUIRED =
             newStatus(511, "Network Authentication Required");
 
     private static HttpResponseStatus newStatus(int statusCode, String reasonPhrase) {
         return new HttpResponseStatus(statusCode, reasonPhrase, true);
     }
 
     /**
      * Returns the {@link HttpResponseStatus} represented by the specified code.
      * If the specified code is a standard HTTP status code, a cached instance
      * will be returned.  Otherwise, a new instance will be returned.
      */
     public static HttpResponseStatus valueOf(int code) {
         HttpResponseStatus status = valueOf0(code);
         return status != null ? status : new HttpResponseStatus(code);
     }
 
     private static HttpResponseStatus valueOf0(int code) {
         switch (code) {
         case 100:
             return CONTINUE;
         case 101:
             return SWITCHING_PROTOCOLS;
         case 102:
             return PROCESSING;
         case 103:
             return EARLY_HINTS;
         case 200:
             return OK;
         case 201:
             return CREATED;
         case 202:
             return ACCEPTED;
         case 203:
             return NON_AUTHORITATIVE_INFORMATION;
         case 204:
             return NO_CONTENT;
         case 205:
             return RESET_CONTENT;
         case 206:
             return PARTIAL_CONTENT;
         case 207:
             return MULTI_STATUS;
         case 300:
             return MULTIPLE_CHOICES;
         case 301:
             return MOVED_PERMANENTLY;
         case 302:
             return FOUND;
         case 303:
             return SEE_OTHER;
         case 304:
             return NOT_MODIFIED;
         case 305:
             return USE_PROXY;
         case 307:
             return TEMPORARY_REDIRECT;
         case 308:
             return PERMANENT_REDIRECT;
         case 400:
             return BAD_REQUEST;
         case 401:
             return UNAUTHORIZED;
         case 402:
             return PAYMENT_REQUIRED;
         case 403:
             return FORBIDDEN;
         case 404:
             return NOT_FOUND;
         case 405:
             return METHOD_NOT_ALLOWED;
         case 406:
             return NOT_ACCEPTABLE;
         case 407:
             return PROXY_AUTHENTICATION_REQUIRED;
         case 408:
             return REQUEST_TIMEOUT;
         case 409:
             return CONFLICT;
         case 410:
             return GONE;
         case 411:
             return LENGTH_REQUIRED;
         case 412:
             return PRECONDITION_FAILED;
         case 413:
             return REQUEST_ENTITY_TOO_LARGE;
         case 414:
             return REQUEST_URI_TOO_LONG;
         case 415:
             return UNSUPPORTED_MEDIA_TYPE;
         case 416:
             return REQUESTED_RANGE_NOT_SATISFIABLE;
         case 417:
             return EXPECTATION_FAILED;
         case 421:
             return MISDIRECTED_REQUEST;
         case 422:
             return UNPROCESSABLE_ENTITY;
         case 423:
             return LOCKED;
         case 424:
             return FAILED_DEPENDENCY;
         case 425:
             return UNORDERED_COLLECTION;
         case 426:
             return UPGRADE_REQUIRED;
         case 428:
             return PRECONDITION_REQUIRED;
         case 429:
             return TOO_MANY_REQUESTS;
         case 431:
             return REQUEST_HEADER_FIELDS_TOO_LARGE;
         case 500:
             return INTERNAL_SERVER_ERROR;
         case 501:
             return NOT_IMPLEMENTED;
         case 502:
             return BAD_GATEWAY;
         case 503:
             return SERVICE_UNAVAILABLE;
         case 504:
             return GATEWAY_TIMEOUT;
         case 505:
             return HTTP_VERSION_NOT_SUPPORTED;
         case 506:
             return VARIANT_ALSO_NEGOTIATES;
         case 507:
             return INSUFFICIENT_STORAGE;
         case 510:
             return NOT_EXTENDED;
         case 511:
             return NETWORK_AUTHENTICATION_REQUIRED;
         }
         return null;
     }
 
     /**
      * Returns the {@link HttpResponseStatus} represented by the specified {@code code} and {@code reasonPhrase}.
      * If the specified code is a standard HTTP status {@code code} and {@code reasonPhrase}, a cached instance
      * will be returned. Otherwise, a new instance will be returned.
      * @param code The response code value.
      * @param reasonPhrase The response code reason phrase.
      * @return the {@link HttpResponseStatus} represented by the specified {@code code} and {@code reasonPhrase}.
      */
     public static HttpResponseStatus valueOf(int code, String reasonPhrase) {
         HttpResponseStatus responseStatus = valueOf0(code);
         return responseStatus != null && responseStatus.reasonPhrase().contentEquals(reasonPhrase) ? responseStatus :
                 new HttpResponseStatus(code, reasonPhrase);
     }
 
     /**
      * Parses the specified HTTP status line into a {@link HttpResponseStatus}. The expected formats of the line are:
      * <ul>
      * <li>{@code statusCode} (e.g. 200)</li>
      * <li>{@code statusCode} {@code reasonPhrase} (e.g. 404 Not Found)</li>
      * </ul>
      *
      * @throws IllegalArgumentException if the specified status line is malformed
      */
     public static HttpResponseStatus parseLine(CharSequence line) {
         return (line instanceof AsciiString) ? parseLine((AsciiString) line) : parseLine(line.toString());
     }
 
     /**
      * Parses the specified HTTP status line into a {@link HttpResponseStatus}. The expected formats of the line are:
      * <ul>
      * <li>{@code statusCode} (e.g. 200)</li>
      * <li>{@code statusCode} {@code reasonPhrase} (e.g. 404 Not Found)</li>
      * </ul>
      *
      * @throws IllegalArgumentException if the specified status line is malformed
      */
     public static HttpResponseStatus parseLine(String line) {
         try {
             int space = line.indexOf(' ');
             return space == -1 ? valueOf(parseInt(line)) :
                     valueOf(parseInt(line.substring(0, space)), line.substring(space + 1));
         } catch (Exception e) {
             throw new IllegalArgumentException("malformed status line: " + line, e);
         }
     }
 
     /**
      * Parses the specified HTTP status line into a {@link HttpResponseStatus}. The expected formats of the line are:
      * <ul>
      * <li>{@code statusCode} (e.g. 200)</li>
      * <li>{@code statusCode} {@code reasonPhrase} (e.g. 404 Not Found)</li>
      * </ul>
      *
      * @throws IllegalArgumentException if the specified status line is malformed
      */
     public static HttpResponseStatus parseLine(AsciiString line) {
         try {
             int space = line.forEachByte(FIND_ASCII_SPACE);
             return space == -1 ? valueOf(line.parseInt()) : valueOf(line.parseInt(0, space), line.toString(space + 1));
         } catch (Exception e) {
             throw new IllegalArgumentException("malformed status line: " + line, e);
         }
     }
 
     private final int code;
     private final AsciiString codeAsText;
     private final HttpStatusClass codeClass;
 
     private final String reasonPhrase;
     private final byte[] bytes;
 
     /**
      * Creates a new instance with the specified {@code code} and the auto-generated default reason phrase.
      */
     private HttpResponseStatus(int code) {
         this(code, HttpStatusClass.valueOf(code).defaultReasonPhrase() + " (" + code + ')', false);
     }
 
     /**
      * Creates a new instance with the specified {@code code} and its {@code reasonPhrase}.
      */
     public HttpResponseStatus(int code, String reasonPhrase) {
         this(code, reasonPhrase, false);
     }
 
     private HttpResponseStatus(int code, String reasonPhrase, boolean bytes) {
         checkPositiveOrZero(code, "code");
         ObjectUtil.checkNotNull(reasonPhrase, "reasonPhrase");
 
         for (int i = 0; i < reasonPhrase.length(); i ++) {
             char c = reasonPhrase.charAt(i);
             // Check prohibited characters.
             switch (c) {
                 case '\n': case '\r':
                     throw new IllegalArgumentException(
                             "reasonPhrase contains one of the following prohibited characters: " +
                                     "\\r\\n: " + reasonPhrase);
             }
         }
 
         this.code = code;
         this.codeClass = HttpStatusClass.valueOf(code);
         String codeString = Integer.toString(code);
         codeAsText = new AsciiString(codeString);
         this.reasonPhrase = reasonPhrase;
         if (bytes) {
             this.bytes = (codeString + ' ' + reasonPhrase).getBytes(CharsetUtil.US_ASCII);
         } else {
             this.bytes = null;
         }
     }
 
     /**
      * Returns the code of this {@link HttpResponseStatus}.
      */
     public int code() {
         return code;
     }
 
     /**
      * Returns the status code as {@link AsciiString}.
      */
     public AsciiString codeAsText() {
         return codeAsText;
     }
 
     /**
      * Returns the reason phrase of this {@link HttpResponseStatus}.
      */
     public String reasonPhrase() {
         return reasonPhrase;
     }
 
     /**
      * Returns the class of this {@link HttpResponseStatus}
      */
     public HttpStatusClass codeClass() {
         return this.codeClass;
     }
 
     @Override
     public int hashCode() {
         return code();
     }
 
     /**
      * Equality of {@link HttpResponseStatus} only depends on {@link #code()}. The
      * reason phrase is not considered for equality.
      */
     @Override
     public boolean equals(Object o) {
         if (!(o instanceof HttpResponseStatus)) {
             return false;
         }
 
         return code() == ((HttpResponseStatus) o).code();
     }
 
     /**
      * Equality of {@link HttpResponseStatus} only depends on {@link #code()}. The
      * reason phrase is not considered for equality.
      */
     @Override
     public int compareTo(HttpResponseStatus o) {
         return code() - o.code();
     }
 
     @Override
     public String toString() {
         return new StringBuilder(reasonPhrase.length() + 4)
             .append(codeAsText)
             .append(' ')
             .append(reasonPhrase)
             .toString();
     }
 
     void encode(ByteBuf buf) {
         if (bytes == null) {
             ByteBufUtil.copy(codeAsText, buf);
             buf.writeByte(SP);
             buf.writeCharSequence(reasonPhrase, CharsetUtil.US_ASCII);
         } else {
             buf.writeBytes(bytes);
         }
     }
 }