/*
 *  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.coyote.ajp;

import java.util.HashMap;
import java.util.Map;

/**
 * Constants.
 *
 * @author Remy Maucherat
 */
public final class Constants {

    public static final int DEFAULT_CONNECTION_TIMEOUT = -1;

    // Prefix codes for message types from server to container
    public static final byte JK_AJP13_FORWARD_REQUEST   = 2;
    public static final byte JK_AJP13_SHUTDOWN          = 7;    // XXX Unused
    public static final byte JK_AJP13_PING_REQUEST      = 8;    // XXX Unused
    public static final byte JK_AJP13_CPING_REQUEST     = 10;

    // Prefix codes for message types from container to server
    public static final byte JK_AJP13_SEND_BODY_CHUNK   = 3;
    public static final byte JK_AJP13_SEND_HEADERS      = 4;
    public static final byte JK_AJP13_END_RESPONSE      = 5;
    public static final byte JK_AJP13_GET_BODY_CHUNK    = 6;
    public static final byte JK_AJP13_CPONG_REPLY       = 9;

    // Integer codes for common response header strings
    public static final int SC_RESP_CONTENT_TYPE        = 0xA001;
    public static final int SC_RESP_CONTENT_LANGUAGE    = 0xA002;
    public static final int SC_RESP_CONTENT_LENGTH      = 0xA003;
    public static final int SC_RESP_DATE                = 0xA004;
    public static final int SC_RESP_LAST_MODIFIED       = 0xA005;
    public static final int SC_RESP_LOCATION            = 0xA006;
    public static final int SC_RESP_SET_COOKIE          = 0xA007;
    public static final int SC_RESP_SET_COOKIE2         = 0xA008;
    public static final int SC_RESP_SERVLET_ENGINE      = 0xA009;
    public static final int SC_RESP_STATUS              = 0xA00A;
    public static final int SC_RESP_WWW_AUTHENTICATE    = 0xA00B;
    public static final int SC_RESP_AJP13_MAX           = 11;

    // Integer codes for common (optional) request attribute names
    public static final byte SC_A_CONTEXT       = 1;  // XXX Unused
    public static final byte SC_A_SERVLET_PATH  = 2;  // XXX Unused
    public static final byte SC_A_REMOTE_USER   = 3;
    public static final byte SC_A_AUTH_TYPE     = 4;
    public static final byte SC_A_QUERY_STRING  = 5;
    public static final byte SC_A_JVM_ROUTE     = 6;
    public static final byte SC_A_SSL_CERT      = 7;
    public static final byte SC_A_SSL_CIPHER    = 8;
    public static final byte SC_A_SSL_SESSION   = 9;
    public static final byte SC_A_SSL_KEY_SIZE  = 11;
    public static final byte SC_A_SECRET        = 12;
    public static final byte SC_A_STORED_METHOD = 13;

    // Used for attributes which are not in the list above
    public static final byte SC_A_REQ_ATTRIBUTE = 10;

    /**
     * AJP private request attributes
     */
    public static final String SC_A_REQ_LOCAL_ADDR  = "AJP_LOCAL_ADDR";
    public static final String SC_A_REQ_REMOTE_PORT = "AJP_REMOTE_PORT";
    public static final String SC_A_SSL_PROTOCOL    = "AJP_SSL_PROTOCOL";

    // Terminates list of attributes
    public static final byte SC_A_ARE_DONE      = (byte)0xFF;

    /**
     * Default maximum total byte size for an AJP packet
     */
    public static final int MAX_PACKET_SIZE = 8192;
    /**
     * Size of basic packet header
     */
    public static final int H_SIZE = 4;

    /**
     * Size of the header metadata
     */
    public static final int  READ_HEAD_LEN = 6;
    public static final int  SEND_HEAD_LEN = 8;

    /**
     * Default maximum size of data that can be sent in one packet
     */
    public static final int  MAX_READ_SIZE = MAX_PACKET_SIZE - READ_HEAD_LEN;
    public static final int  MAX_SEND_SIZE = MAX_PACKET_SIZE - SEND_HEAD_LEN;

    // Translates integer codes to names of HTTP methods
    private static final String [] methodTransArray = {
            "OPTIONS",
            "GET",
            "HEAD",
            "POST",
            "PUT",
            "DELETE",
            "TRACE",
            "PROPFIND",
            "PROPPATCH",
            "MKCOL",
            "COPY",
            "MOVE",
            "LOCK",
            "UNLOCK",
            "ACL",
            "REPORT",
            "VERSION-CONTROL",
            "CHECKIN",
            "CHECKOUT",
            "UNCHECKOUT",
            "SEARCH",
            "MKWORKSPACE",
            "UPDATE",
            "LABEL",
            "MERGE",
            "BASELINE-CONTROL",
            "MKACTIVITY"
    };

    /**
     * Converts an AJP coded HTTP method to the method name.
     * @param code the coded value
     * @return the string value of the method
     */
    public static String getMethodForCode(final int code) {
        return methodTransArray[code];
    }

    public static final int SC_M_JK_STORED = (byte) 0xFF;

    // id's for common request headers
    public static final int SC_REQ_ACCEPT          = 1;
    public static final int SC_REQ_ACCEPT_CHARSET  = 2;
    public static final int SC_REQ_ACCEPT_ENCODING = 3;
    public static final int SC_REQ_ACCEPT_LANGUAGE = 4;
    public static final int SC_REQ_AUTHORIZATION   = 5;
    public static final int SC_REQ_CONNECTION      = 6;
    public static final int SC_REQ_CONTENT_TYPE    = 7;
    public static final int SC_REQ_CONTENT_LENGTH  = 8;
    public static final int SC_REQ_COOKIE          = 9;
    public static final int SC_REQ_COOKIE2         = 10;
    public static final int SC_REQ_HOST            = 11;
    public static final int SC_REQ_PRAGMA          = 12;
    public static final int SC_REQ_REFERER         = 13;
    public static final int SC_REQ_USER_AGENT      = 14;

    // Translates integer codes to request header names
    private static final String [] headerTransArray = {
            "accept",
            "accept-charset",
            "accept-encoding",
            "accept-language",
            "authorization",
            "connection",
            "content-type",
            "content-length",
            "cookie",
            "cookie2",
            "host",
            "pragma",
            "referer",
            "user-agent"
    };

    /**
     * Converts an AJP coded HTTP request header to the header name.
     * @param code the coded value
     * @return the string value of the header name
     */
    public static String getHeaderForCode(final int code) {
        return headerTransArray[code];
    }

    // Translates integer codes to response header names
    private static final String [] responseTransArray = {
            "Content-Type",
            "Content-Language",
            "Content-Length",
            "Date",
            "Last-Modified",
            "Location",
            "Set-Cookie",
            "Set-Cookie2",
            "Servlet-Engine",
            "Status",
            "WWW-Authenticate"
    };

    /**
     * Converts an AJP coded response header name to the HTTP response header name.
     * @param code the coded value
     * @return the string value of the header
     */
    public static String getResponseHeaderForCode(final int code) {
        return responseTransArray[code];
    }

    private static final Map<String,Integer>  responseTransMap = new HashMap<>(20);

    static {
        try {
            int i;
            for (i = 0; i < SC_RESP_AJP13_MAX; i++) {
                responseTransMap.put(getResponseHeaderForCode(i), Integer.valueOf(0xA001 + i));
            }
        }
        catch (Exception e) {
            // Do nothing
        }
    }

    public static int getResponseAjpIndex(String header) {
        Integer i = responseTransMap.get(header);
        if (i == null) {
            return 0;
        } else {
            return i.intValue();
        }
    }
}
