/******************************************************************************
 * Copyright © 2013-2016 The Nxt Core Developers.                             *
 *                                                                            *
 * See the AUTHORS.txt, DEVELOPER-AGREEMENT.txt and LICENSE.txt files at      *
 * the top-level directory of this distribution for the individual copyright  *
 * holder information and the developer policies on copyright and licensing.  *
 *                                                                            *
 * Unless otherwise agreed in a custom licensing agreement, no part of the    *
 * Nxt software, including this file, may be copied, modified, propagated,    *
 * or distributed except according to the terms contained in the LICENSE.txt  *
 * file.                                                                      *
 *                                                                            *
 * Removal or modification of this copyright notice is prohibited.            *
 *                                                                            *
 ******************************************************************************/

package nxt.http;

import nxt.crypto.HashFunction;
import nxt.util.Convert;
import org.json.simple.JSONObject;
import org.json.simple.JSONStreamAware;

import javax.servlet.http.HttpServletRequest;

public final class Hash extends APIServlet.APIRequestHandler {

    static final Hash instance = new Hash();

    private Hash() {
        super(new APITag[] {APITag.UTILS}, "hashAlgorithm", "secret", "secretIsText");
    }

    @Override
    JSONStreamAware processRequest(HttpServletRequest req) throws ParameterException {

        byte algorithm = ParameterParser.getByte(req, "hashAlgorithm", (byte) 0, Byte.MAX_VALUE, false);
        HashFunction hashFunction = null;
        try {
            hashFunction = HashFunction.getHashFunction(algorithm);
        } catch (IllegalArgumentException ignore) {}
        if (hashFunction == null) {
            return JSONResponses.INCORRECT_HASH_ALGORITHM;
        }

        boolean secretIsText = "true".equalsIgnoreCase(req.getParameter("secretIsText"));
        byte[] secret;
        try {
            secret = secretIsText ? Convert.toBytes(req.getParameter("secret"))
                    : Convert.parseHexString(req.getParameter("secret"));
        } catch (RuntimeException e) {
            return JSONResponses.INCORRECT_SECRET;
        }
        if (secret == null || secret.length == 0) {
            return JSONResponses.MISSING_SECRET;
        }

        JSONObject response = new JSONObject();
        response.put("hash", Convert.toHexString(hashFunction.hash(secret)));
        return response;
    }

    @Override
    boolean allowRequiredBlockParameters() {
        return false;
    }

    @Override
    boolean requireBlockchain() {
        return false;
    }

}