package froala.editor;

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Calendar;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Hex;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.multipart.MultipartFile;

import egovframework.rte.fdl.cmmn.exception.EgovBizException;

/**
 * Basic utils.
 *
 * @author florin@froala.com
 *
 */
public final class Utils {

	private static final Logger LOGGER = LoggerFactory.getLogger(Utils.class);

	/**
	 * Private constructor.
	 */
	private Utils() {

	}

	public static String generateUniqueString() throws NoSuchAlgorithmException {

		String miliseconds = System.currentTimeMillis() + "";
		MessageDigest d = null;
		d = java.security.MessageDigest.getInstance("SHA-256");
		d.reset();
		d.update(miliseconds.getBytes());
		return bytesToHex(d.digest());
	}

	public static String bytesToHex(byte[] in) {
		StringBuilder builder = new StringBuilder();
		for (byte b : in) {
			builder.append(String.format("%02x", b));
		}
		return builder.toString();
	}

//	public static String getFileName(Part part) {
//		for (String cd : part.getHeader("content-disposition").split(";")) {
//			if (cd.trim().startsWith("filename")) {
//				return cd.substring(cd.indexOf('=') + 1).trim().replace("\"", "");
//			}
//		}
//		return null;
//	}

	public static String getFileName(MultipartFile file) {
		if( !file.isEmpty() ) {
			return file.getOriginalFilename();
		};
		return null;
	}

	public static byte[] hmac(byte[] key, String data) {
		Mac sha256_HMAC;
		byte[] result = null;
		try {
			sha256_HMAC = Mac.getInstance("HmacSHA256");
			SecretKeySpec secret_key = new SecretKeySpec(key, "HmacSHA256");
			sha256_HMAC.init(secret_key);
			result = sha256_HMAC.doFinal(data.getBytes("UTF-8"));
		} catch (NoSuchAlgorithmException | InvalidKeyException | IllegalStateException | UnsupportedEncodingException e) {
			return null;
		}
		return result;
	}

	public static String hmac_hex(byte[] key, String data) throws EgovBizException {
		return new String(Hex.encodeHex(hmac(key, data)));
	}

	public static String getAddDateRoute(String route) {
		if( route == null ) return "";

		// 파일 저장 경로에 날짜 추가
		Calendar cal = Calendar.getInstance();
		//현재 년도, 월, 일
		int year = cal.get(Calendar.YEAR);
		int month = cal.get(Calendar.MONTH) + 1;
		int date = cal.get(Calendar.DATE);
		return route + year + "/" + month + "/" + date + "/";
	}

	public static String getAddTempRoute(String route) {
		if( route == null ) return "";

		// 파일 저장 경로에 임시경로 추가
		String directory = null;
		try {
			directory = Utils.generateUniqueString();
		} catch (NoSuchAlgorithmException e) {
			LOGGER.error("NoSuchAlgorithmException! {}", e);
			directory = "";
		}

		return route + directory + "/";
	}
}