package org.json;

/*
Public Domain.
*/

import java.util.Locale;

/**
 * Convert an HTTP header to a JSONObject and back.
 * @author JSON.org
 * @version 2015-12-09
 */
public class HTTP {

    /**
     * Constructs a new HTTP object.
     */
    public HTTP() {
    }

    /** Carriage return/line feed. */
    public static final String CRLF = "\r\n";

    /**
     * Convert an HTTP header string into a JSONObject. It can be a request
     * header or a response header. A request header will contain
     * <pre>{
     *    Method: "POST" (for example),
     *    "Request-URI": "/" (for example),
     *    "HTTP-Version": "HTTP/1.1" (for example)
     * }</pre>
     * A response header will contain
     * <pre>{
     *    "HTTP-Version": "HTTP/1.1" (for example),
     *    "Status-Code": "200" (for example),
     *    "Reason-Phrase": "OK" (for example)
     * }</pre>
     * In addition, the other parameters in the header will be captured, using
     * the HTTP field names as JSON names, so that <pre>{@code
     *    Date: Sun, 26 May 2002 18:06:04 GMT
     *    Cookie: Q=q2=PPEAsg--; B=677gi6ouf29bn&b=2&f=s
     *    Cache-Control: no-cache}</pre>
     * become
     * <pre>{@code
     *    Date: "Sun, 26 May 2002 18:06:04 GMT",
     *    Cookie: "Q=q2=PPEAsg--; B=677gi6ouf29bn&b=2&f=s",
     *    "Cache-Control": "no-cache",
     * ...}</pre>
     * It does no further checking or conversion. It does not parse dates.
     * It does not do '%' transforms on URLs.
     * @param string An HTTP header string.
     * @return A JSONObject containing the elements and attributes
     * of the XML string.
     * @throws JSONException if a called function fails
     */
    public static JSONObject toJSONObject(String string) throws JSONException {
        JSONObject     jo = new JSONObject();
        HTTPTokener    x = new HTTPTokener(string);
        String         token;

        token = x.nextToken();
        if (token.toUpperCase(Locale.ROOT).startsWith("HTTP")) {

// Response

            jo.put("HTTP-Version", token);
            jo.put("Status-Code", x.nextToken());
            jo.put("Reason-Phrase", x.nextTo('\0'));
            x.next();

        } else {

// Request

            jo.put("Method", token);
            jo.put("Request-URI", x.nextToken());
            jo.put("HTTP-Version", x.nextToken());
        }

// Fields

        while (x.more()) {
            String name = x.nextTo(':');
            x.next(':');
            jo.put(name, x.nextTo('\0'));
            x.next();
        }
        return jo;
    }


    /**
     * Convert a JSONObject into an HTTP header. A request header must contain
     * <pre>{
     *    Method: "POST" (for example),
     *    "Request-URI": "/" (for example),
     *    "HTTP-Version": "HTTP/1.1" (for example)
     * }</pre>
     * A response header must contain
     * <pre>{
     *    "HTTP-Version": "HTTP/1.1" (for example),
     *    "Status-Code": "200" (for example),
     *    "Reason-Phrase": "OK" (for example)
     * }</pre>
     * Any other members of the JSONObject will be output as HTTP fields.
     * The result will end with two CRLF pairs.
     * @param jo A JSONObject
     * @return An HTTP header string.
     * @throws JSONException if the object does not contain enough
     *  information.
     */
    public static String toString(JSONObject jo) throws JSONException {
        StringBuilder       sb = new StringBuilder();
        if (jo.has("Status-Code") && jo.has("Reason-Phrase")) {
            sb.append(jo.getString("HTTP-Version"));
            sb.append(' ');
            sb.append(jo.getString("Status-Code"));
            sb.append(' ');
            sb.append(jo.getString("Reason-Phrase"));
        } else if (jo.has("Method") && jo.has("Request-URI")) {
            sb.append(jo.getString("Method"));
            sb.append(' ');
            sb.append('"');
            sb.append(jo.getString("Request-URI"));
            sb.append('"');
            sb.append(' ');
            sb.append(jo.getString("HTTP-Version"));
        } else {
            throw new JSONException("Not enough material for an HTTP header.");
        }
        sb.append(CRLF);
        // Don't use the new entrySet API to maintain Android support
        for (final String key : jo.keySet()) {
            String value = jo.optString(key);
            if (!"HTTP-Version".equals(key)      && !"Status-Code".equals(key) &&
                    !"Reason-Phrase".equals(key) && !"Method".equals(key) &&
                    !"Request-URI".equals(key)   && !JSONObject.NULL.equals(value)) {
                sb.append(key);
                sb.append(": ");
                sb.append(jo.optString(key));
                sb.append(CRLF);
            }
        }
        sb.append(CRLF);
        return sb.toString();
    }
}
