package org.json;

import java.util.Locale;

/*
Copyright (c) 2002 JSON.org

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

The Software shall be used for Good, not Evil.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

/**
 * Convert a web browser cookie specification to a JSONObject and back.
 * JSON and Cookies are both notations for name/value pairs.
 * See also: <a href="https://tools.ietf.org/html/rfc6265">https://tools.ietf.org/html/rfc6265</a>
 * @author JSON.org
 * @version 2015-12-09
 */
public class Cookie {

    /**
     * Produce a copy of a string in which the characters '+', '%', '=', ';'
     * and control characters are replaced with "%hh". This is a gentle form
     * of URL encoding, attempting to cause as little distortion to the
     * string as possible. The characters '=' and ';' are meta characters in
     * cookies. By convention, they are escaped using the URL-encoding. This is
     * only a convention, not a standard. Often, cookies are expected to have
     * encoded values. We encode '=' and ';' because we must. We encode '%' and
     * '+' because they are meta characters in URL encoding.
     * @param string The source string.
     * @return       The escaped result.
     */
    public static String escape(String string) {
        char            c;
        String          s = string.trim();
        int             length = s.length();
        StringBuilder   sb = new StringBuilder(length);
        for (int i = 0; i < length; i += 1) {
            c = s.charAt(i);
            if (c < ' ' || c == '+' || c == '%' || c == '=' || c == ';') {
                sb.append('%');
                sb.append(Character.forDigit((char)((c >>> 4) & 0x0f), 16));
                sb.append(Character.forDigit((char)(c & 0x0f), 16));
            } else {
                sb.append(c);
            }
        }
        return sb.toString();
    }


    /**
     * Convert a cookie specification string into a JSONObject. The string
     * must contain a name value pair separated by '='. The name and the value
     * will be unescaped, possibly converting '+' and '%' sequences. The
     * cookie properties may follow, separated by ';', also represented as
     * name=value (except the Attribute properties like "Secure" or "HttpOnly",
     * which do not have a value. The value {@link Boolean#TRUE} will be used for these).
     * The name will be stored under the key "name", and the value will be
     * stored under the key "value". This method does not do checking or
     * validation of the parameters. It only converts the cookie string into
     * a JSONObject. All attribute names are converted to lower case keys in the
     * JSONObject (HttpOnly =&gt; httponly). If an attribute is specified more than
     * once, only the value found closer to the end of the cookie-string is kept.
     * @param string The cookie specification string.
     * @return A JSONObject containing "name", "value", and possibly other
     *  members.
     * @throws JSONException If there is an error parsing the Cookie String.
     * Cookie strings must have at least one '=' character and the 'name'
     * portion of the cookie must not be blank.
     */
    public static JSONObject toJSONObject(String string) {
        final JSONObject     jo = new JSONObject();
        String         name;
        Object         value;
        
        
        JSONTokener x = new JSONTokener(string);
        
        name = unescape(x.nextTo('=').trim());
        //per RFC6265, if the name is blank, the cookie should be ignored.
        if("".equals(name)) {
            throw new JSONException("Cookies must have a 'name'");
        }
        jo.put("name", name);
        // per RFC6265, if there is no '=', the cookie should be ignored.
        // the 'next' call here throws an exception if the '=' is not found.
        x.next('=');
        jo.put("value", unescape(x.nextTo(';')).trim());
        // discard the ';'
        x.next();
        // parse the remaining cookie attributes
        while (x.more()) {
            name = unescape(x.nextTo("=;")).trim().toLowerCase(Locale.ROOT);
            // don't allow a cookies attributes to overwrite it's name or value.
            if("name".equalsIgnoreCase(name)) {
                throw new JSONException("Illegal attribute name: 'name'");
            }
            if("value".equalsIgnoreCase(name)) {
                throw new JSONException("Illegal attribute name: 'value'");
            }
            // check to see if it's a flag property
            if (x.next() != '=') {
                value = Boolean.TRUE;
            } else {
                value = unescape(x.nextTo(';')).trim();
                x.next();
            }
            // only store non-blank attributes
            if(!"".equals(name) && !"".equals(value)) {
                jo.put(name, value);
            }
        }
        return jo;
    }


    /**
     * Convert a JSONObject into a cookie specification string. The JSONObject
     * must contain "name" and "value" members (case insensitive).
     * If the JSONObject contains other members, they will be appended to the cookie
     * specification string. User-Agents are instructed to ignore unknown attributes,
     * so ensure your JSONObject is using only known attributes.
     * See also: <a href="https://tools.ietf.org/html/rfc6265">https://tools.ietf.org/html/rfc6265</a>
     * @param jo A JSONObject
     * @return A cookie specification string
     * @throws JSONException thrown if the cookie has no name.
     */
    public static String toString(JSONObject jo) throws JSONException {
        StringBuilder sb = new StringBuilder();
        
        String name = null;
        Object value = null;
        for(String key : jo.keySet()){
            if("name".equalsIgnoreCase(key)) {
                name = jo.getString(key).trim();
            }
            if("value".equalsIgnoreCase(key)) {
                value=jo.getString(key).trim();
            }
            if(name != null && value != null) {
                break;
            }
        }
        
        if(name == null || "".equals(name.trim())) {
            throw new JSONException("Cookie does not have a name");
        }
        if(value == null) {
            value = "";
        }
        
        sb.append(escape(name));
        sb.append("=");
        sb.append(escape((String)value));
        
        for(String key : jo.keySet()){
            if("name".equalsIgnoreCase(key)
                    || "value".equalsIgnoreCase(key)) {
                // already processed above
                continue;
            }
            value = jo.opt(key);
            if(value instanceof Boolean) {
                if(Boolean.TRUE.equals(value)) {
                    sb.append(';').append(escape(key));
                }
                // don't emit false values
            } else {
                sb.append(';')
                    .append(escape(key))
                    .append('=')
                    .append(escape(value.toString()));
            }
        }
        
        return sb.toString();
    }

    /**
     * Convert <code>%</code><i>hh</i> sequences to single characters, and
     * convert plus to space.
     * @param string A string that may contain
     *      <code>+</code>&nbsp;<small>(plus)</small> and
     *      <code>%</code><i>hh</i> sequences.
     * @return The unescaped string.
     */
    public static String unescape(String string) {
        int length = string.length();
        StringBuilder sb = new StringBuilder(length);
        for (int i = 0; i < length; ++i) {
            char c = string.charAt(i);
            if (c == '+') {
                c = ' ';
            } else if (c == '%' && i + 2 < length) {
                int d = JSONTokener.dehexchar(string.charAt(i + 1));
                int e = JSONTokener.dehexchar(string.charAt(i + 2));
                if (d >= 0 && e >= 0) {
                    c = (char)(d * 16 + e);
                    i += 2;
                }
            }
            sb.append(c);
        }
        return sb.toString();
    }
}
