/*
 * Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved.
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed 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 javax.servlet.http;

import javax.servlet.ServletInputStream;
import java.util.Hashtable;
import java.util.ResourceBundle;
import java.util.StringTokenizer;
import java.io.IOException;

/**
 * @deprecated		As of Java(tm) Servlet API 2.3. 
 *			These methods were only useful
 *			with the default encoding and have been moved
 *			to the request interfaces.
 *
 */
@Deprecated
public class HttpUtils {

    private static final String LSTRING_FILE =
	"javax.servlet.http.LocalStrings";
    private static ResourceBundle lStrings =
	ResourceBundle.getBundle(LSTRING_FILE);
        
    
    /**
     * Constructs an empty <code>HttpUtils</code> object.
     */
    public HttpUtils() {}
    

    /**
     * Parses a query string passed from the client to the
     * server and builds a <code>HashTable</code> object
     * with key-value pairs. 
     * The query string should be in the form of a string
     * packaged by the GET or POST method, that is, it
     * should have key-value pairs in the form <i>key=value</i>,
     * with each pair separated from the next by a &amp; character.
     *
     * <p>A key can appear more than once in the query string
     * with different values. However, the key appears only once in 
     * the hashtable, with its value being
     * an array of strings containing the multiple values sent
     * by the query string.
     * 
     * <p>The keys and values in the hashtable are stored in their
     * decoded form, so
     * any + characters are converted to spaces, and characters
     * sent in hexadecimal notation (like <i>%xx</i>) are
     * converted to ASCII characters.
     *
     * @param s		a string containing the query to be parsed
     *
     * @return		a <code>HashTable</code> object built
     * 			from the parsed key-value pairs
     *
     * @exception IllegalArgumentException if the query string is invalid
     */
    public static Hashtable<String, String[]> parseQueryString(String s) {

        String valArray[] = null;
	
        if (s == null) {
            throw new IllegalArgumentException();
        }

        Hashtable<String, String[]> ht = new Hashtable<String, String[]>();
        StringBuilder sb = new StringBuilder();
        StringTokenizer st = new StringTokenizer(s, "&");
        while (st.hasMoreTokens()) {
        String pair = st.nextToken();
        int pos = pair.indexOf('=');
        if (pos == -1) {
            // XXX
            // should give more detail about the illegal argument
            throw new IllegalArgumentException();
        }
        String key = parseName(pair.substring(0, pos), sb);
        String val = parseName(pair.substring(pos+1, pair.length()), sb);
        if (ht.containsKey(key)) {
            String oldVals[] = ht.get(key);
            valArray = new String[oldVals.length + 1];
            for (int i = 0; i < oldVals.length; i++) {
                valArray[i] = oldVals[i];
            }
            valArray[oldVals.length] = val;
        } else {
            valArray = new String[1];
            valArray[0] = val;
        }
        ht.put(key, valArray);
    }

	return ht;
    }


    /**
     *
     * Parses data from an HTML form that the client sends to 
     * the server using the HTTP POST method and the 
     * <i>application/x-www-form-urlencoded</i> MIME type.
     *
     * <p>The data sent by the POST method contains key-value
     * pairs. A key can appear more than once in the POST data
     * with different values. However, the key appears only once in 
     * the hashtable, with its value being
     * an array of strings containing the multiple values sent
     * by the POST method.
     *
     * <p>The keys and values in the hashtable are stored in their
     * decoded form, so
     * any + characters are converted to spaces, and characters
     * sent in hexadecimal notation (like <i>%xx</i>) are
     * converted to ASCII characters.
     *
     * @param len	an integer specifying the length,
     *			in characters, of the 
     *			<code>ServletInputStream</code>
     *			object that is also passed to this
     *			method
     *
     * @param in	the <code>ServletInputStream</code>
     *			object that contains the data sent
     *			from the client
     * 
     * @return		a <code>HashTable</code> object built
     *			from the parsed key-value pairs
     *
     * @exception IllegalArgumentException if the data
     * sent by the POST method is invalid
     */
    public static Hashtable<String, String[]> parsePostData(int len, 
                ServletInputStream in) {
	// XXX
	// should a length of 0 be an IllegalArgumentException
	
	if (len <=0) {
            // cheap hack to return an empty hash
	    return new Hashtable<String, String[]>(); 
        }

	if (in == null) {
	    throw new IllegalArgumentException();
	}
	
	//
	// Make sure we read the entire POSTed body.
	//
        byte[] postedBytes = new byte [len];
        try {
            int offset = 0;
       
	    do {
		int inputLen = in.read (postedBytes, offset, len - offset);
		if (inputLen <= 0) {
		    String msg = lStrings.getString("err.io.short_read");
		    throw new IllegalArgumentException (msg);
		}
		offset += inputLen;
	    } while ((len - offset) > 0);

	} catch (IOException e) {
	    throw new IllegalArgumentException(e.getMessage());
	}

        // XXX we shouldn't assume that the only kind of POST body
        // is FORM data encoded using ASCII or ISO Latin/1 ... or
        // that the body should always be treated as FORM data.
        //

        try {
            String postedBody = new String(postedBytes, 0, len, "8859_1");
            return parseQueryString(postedBody);
        } catch (java.io.UnsupportedEncodingException e) {
            // XXX function should accept an encoding parameter & throw this
            // exception.  Otherwise throw something expected.
            throw new IllegalArgumentException(e.getMessage());
        }
    }


    /*
     * Parse a name in the query string.
     */
    private static String parseName(String s, StringBuilder sb) {
        sb.setLength(0);
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i); 
            switch (c) {
                case '+':
                    sb.append(' ');
                    break;
                case '%':
                    try {
                        sb.append((char) Integer.parseInt(s.substring(i+1, i+3), 
                                16));
                        i += 2;
                    } catch (NumberFormatException e) {
                        // XXX
                        // need to be more specific about illegal arg
                        throw new IllegalArgumentException();
                    } catch (StringIndexOutOfBoundsException e) {
                        String rest  = s.substring(i);
                        sb.append(rest);
                        if (rest.length()==2)
                            i++;
                        }

                        break;
                default:
                    sb.append(c);
                    break;
            }
        }

        return sb.toString();
    }


    /**
     *
     * Reconstructs the URL the client used to make the request,
     * using information in the <code>HttpServletRequest</code> object.
     * The returned URL contains a protocol, server name, port
     * number, and server path, but it does not include query
     * string parameters.
     * 
     * <p>Because this method returns a <code>StringBuffer</code>,
     * not a string, you can modify the URL easily, for example,
     * to append query parameters.
     *
     * <p>This method is useful for creating redirect messages
     * and for reporting errors.
     *
     * @param req	a <code>HttpServletRequest</code> object
     *			containing the client's request
     * 
     * @return		a <code>StringBuffer</code> object containing
     *			the reconstructed URL
     */
    public static StringBuffer getRequestURL (HttpServletRequest req) {
        StringBuffer url = new StringBuffer();
        String scheme = req.getScheme ();
        int port = req.getServerPort ();
        String urlPath = req.getRequestURI();

        //String		servletPath = req.getServletPath ();
        //String		pathInfo = req.getPathInfo ();

        url.append (scheme);		// http, https
        url.append ("://");
        url.append (req.getServerName ());
        if ((scheme.equals ("http") && port != 80)
        || (scheme.equals ("https") && port != 443)) {
            url.append (':');
            url.append (req.getServerPort ());
        }
        //if (servletPath != null)
        //    url.append (servletPath);
        //if (pathInfo != null)
        //    url.append (pathInfo);
        url.append(urlPath);

        return url;
    }
}