/******************************************************************************
 * 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.NxtException;
import nxt.util.Convert;
import nxt.util.Logger;
import nxt.util.Search;
import org.json.simple.JSONObject;
import org.json.simple.JSONStreamAware;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.Part;
import java.io.IOException;

import static nxt.http.JSONResponses.INCORRECT_TAGGED_DATA_FILE;

public final class DetectMimeType extends APIServlet.APIRequestHandler {

    static final DetectMimeType instance = new DetectMimeType();

    private DetectMimeType() {
        super("file", new APITag[] {APITag.DATA, APITag.UTILS}, "data", "filename", "isText");
    }

    @Override
    JSONStreamAware processRequest(HttpServletRequest req) throws NxtException {
        String filename = Convert.nullToEmpty(req.getParameter("filename")).trim();
        String dataValue = Convert.emptyToNull(req.getParameter("data"));
        byte[] data;
        if (dataValue == null) {
            try {
                Part part = req.getPart("file");
                if (part == null) {
                    throw new ParameterException(INCORRECT_TAGGED_DATA_FILE);
                }
                ParameterParser.FileData fileData = new ParameterParser.FileData(part).invoke();
                data = fileData.getData();
                // Depending on how the client submits the form, the filename, can be a regular parameter
                // or encoded in the multipart form. If its not a parameter we take from the form
                if (filename.isEmpty() && fileData.getFilename() != null) {
                    filename = fileData.getFilename();
                }
            } catch (IOException | ServletException e) {
                Logger.logDebugMessage("error in reading file data", e);
                throw new ParameterException(INCORRECT_TAGGED_DATA_FILE);
            }
        } else {
            boolean isText = !"false".equalsIgnoreCase(req.getParameter("isText"));
            data = isText ? Convert.toBytes(dataValue) : Convert.parseHexString(dataValue);
        }

        JSONObject response = new JSONObject();
        response.put("type", Search.detectMimeType(data, filename));
        return response;
    }

    @Override
    boolean requirePost() {
        return true;
    }

    @Override
    boolean allowRequiredBlockParameters() {
        return false;
    }

    @Override
    boolean requireBlockchain() {
        return false;
    }

}