/*
 * Copyright (c) 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package com.sun.ejte.ccl.webrunner.proxy;

import java.util.*;

/**
 * MIME is an internet standard for communicating multimedia content over e-mail systems.MimeHeader extends HashTable so that it can store key value pairs.
 * @author       Deepa Singh(deepa.singh@sun.com)
 *Company: Sun Microsystems Inc
 *
 */
public class MimeHeader extends Hashtable
{
    /**
     * Takes a String as a parameter and parses it.Takes a raw MIME-formatted String and enter its key/value pairs into a given instance of MimeHeader.Uses
     *StringTokenizer to split the input data into individual lines marked by CRLF(\r\n) sequence.
     * @author       Deepa Singh(deepa.singh@sun.com)
     * @return       void
     * @param        data    The string to be parsed
     */
    void parse(String data)
    {
        StringTokenizer st=new StringTokenizer(data,"\r\n");
        while(st.hasMoreTokens())
        {
            String s=st.nextToken();
            int colon=s.indexOf(':');
            String key=s.substring(0,colon);
            String val=s.substring(colon+2);
            put(key,val);
        }
    }

    /**
     * Default Constructor
     *Class is a subclass of HashTable so that it can conveneintly store and retreive the key/value pairs
     *associated with a MIME header.It creates a blank MimeHeader with no keys.
     * @author       Deepa Singh(deepa.singh@sun.com)
     *
     * @param        None
     */
    MimeHeader(){}

    /**
     * This constructor takes strng formatted as MIME header and parses it for the initial contents of the objects.
     * @author       Deepa Singh(deepa.singh@sun.com)
     *
     * @param        d    The string to be parsed
     */
    MimeHeader(String d)
    {
        parse(d);
    }

    /**
     * Converts to String .It takes current key/value pairs stored in the MimeHeader and returns a string representation of them in
     *MIME format, where keys are printed followed by colon and a space, and then value followed by CRLF.
     * @author       Deepa Singh(deepa.singh@sun.com)
     * @return       String
     */
    public String toString()
    {
        String ret="";
        Enumeration e=keys();
        while(e.hasMoreElements())
        {
            String key=(String)e.nextElement();
            String val=(String)get(key);
            ret+=key + ": " + val + "\r\n";
        }
        return ret;
    }

    /**
     *To remove the discrepancy in MIME specification for "Content-Type" and "content-type" and "Content-Length" to "content-length"
     *To avoid problems, all incoming and outgoing MimeHeader keys are converted to canonical form.
     * @author       Deepa Singh(deepa.singh@sun.com)
     * @return       String
     * @param        ms    String to be operated upon
     */
    private String fix(String ms)
    {
        char chars[]=ms.toLowerCase().toCharArray();
        boolean upcaseNext=true;
        for(int i=0;i<chars.length-1;i++)
        {
            char ch=chars[i];
            if(upcaseNext && 'a' <=ch && ch <='z')
            {
                chars[i]=(char)(ch-('a'-'A'));
            }
            upcaseNext=ch=='-';
        }
        return new String(chars);
    }

    /**
     * @author       Deepa Singh(deepa.singh@sun.com)
     * @return       String
     * @param        key    String to be fetched
     */
    public String get(String key)
    {
        return (String)super.get(fix(key));
    }

    /**
     *
     * @author       Deepa Singh(deepa.singh@sun.com)
     * @return       void
     * @param        key        The Key String
     * @param        val      The value String
     */
    public void put(String key,String val)
    {
        super.put(fix(key),val);
    }


}