/*
    * Copyright 2014 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.util.AsciiString;
  
  /**
   * The class of HTTP status.
   */
  public enum HttpStatusClass {
      /**
       * The informational class (1xx)
       */
      INFORMATIONAL(100, 200, "Informational"),
      /**
       * The success class (2xx)
       */
      SUCCESS(200, 300, "Success"),
      /**
       * The redirection class (3xx)
       */
      REDIRECTION(300, 400, "Redirection"),
      /**
       * The client error class (4xx)
       */
      CLIENT_ERROR(400, 500, "Client Error"),
      /**
       * The server error class (5xx)
       */
      SERVER_ERROR(500, 600, "Server Error"),
      /**
       * The unknown class
       */
      UNKNOWN(0, 0, "Unknown Status") {
          @Override
          public boolean contains(int code) {
              return code < 100 || code >= 600;
          }
      };
  
      private static final HttpStatusClass[] statusArray = new HttpStatusClass[6];
      static {
          statusArray[1] = INFORMATIONAL;
          statusArray[2] = SUCCESS;
          statusArray[3] = REDIRECTION;
          statusArray[4] = CLIENT_ERROR;
          statusArray[5] = SERVER_ERROR;
      }
  
      /**
       * Returns the class of the specified HTTP status code.
       */
      public static HttpStatusClass valueOf(int code) {
          if (UNKNOWN.contains(code)) {
              return UNKNOWN;
          }
          return statusArray[fast_div100(code)];
      }
  
      /**
       * @param dividend Must >= 0
       * @return dividend/100
       */
      private static int fast_div100(int dividend) {
          return (int) ((dividend * 1374389535L) >> 37);
      }
  
      /**
       * Returns the class of the specified HTTP status code.
       * @param code Just the numeric portion of the http status code.
       */
      public static HttpStatusClass valueOf(CharSequence code) {
          if (code != null && code.length() == 3) {
              char c0 = code.charAt(0);
              return isDigit(c0) && isDigit(code.charAt(1)) && isDigit(code.charAt(2)) ? valueOf(digit(c0) * 100)
                                                                                       : UNKNOWN;
          }
          return UNKNOWN;
      }
  
      private static int digit(char c) {
          return c - '0';
      }
  
      private static boolean isDigit(char c) {
         return c >= '0' && c <= '9';
     }
 
     private final int min;
     private final int max;
     private final AsciiString defaultReasonPhrase;
 
     HttpStatusClass(int min, int max, String defaultReasonPhrase) {
         this.min = min;
         this.max = max;
         this.defaultReasonPhrase = AsciiString.cached(defaultReasonPhrase);
     }
 
     /**
      * Returns {@code true} if and only if the specified HTTP status code falls into this class.
      */
     public boolean contains(int code) {
         return code >= min && code < max;
     }
 
     /**
      * Returns the default reason phrase of this HTTP status class.
      */
     AsciiString defaultReasonPhrase() {
         return defaultReasonPhrase;
     }
 }