EDIT

/**

* Copyright (C) 2007 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.cdm.model.agent;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import org.apache.commons.lang3.StringUtils;

import eu.etaxonomy.cdm.common.UTF8;

/**

 * A class for handling ORCIDs (http://https://orcid.org/, https://support.orcid.org/hc/en-us/articles/360006897674).

 * It offers parsing and formatting functionality as well as validation.

 * A {@link ORCID} object can only be created by syntactic valid input.

 * It internally stores 1 strings (length=16).

 *

 *

 * @author a.mueller

 * @since 2019-11-08

 */

public final class ORCID implements java.io.Serializable{

    /**

     * Explicit serialVersionUID for interoperability.

     */

    private static final long serialVersionUID = 4304992020966546747L;

    public static final String ORCID_ORG = "orcid.org/";

	/**

	 * The default public ORCID proxy server

	 */

	public static final String HTTP_ORCID_ORG = "https://" + ORCID_ORG;

    private volatile transient int hashCode = -1;	// Zero ==> undefined

//********************************* VARIABLES *************************************/

	/**

	 * The base digits without prefix, checksum and hyphens("-")

	 */

	private String baseNumber;

	/**

	 * The checksum.

	 * @see #checkDigit()

	 */

	private String checkSum;

// ***************************** FACTORY METHODS ***************************************/

	public static ORCID fromString(String orcid) throws IllegalArgumentException{

		return new ORCID(orcid);

	}

// ******************************* CONSTRUCTOR ************************************/

	private ORCID(){} //empty constructor required for JAXB

//    /**

//     * Creates a doi by its registrantCode and its suffix

//     * @param registrantCode the registrant code, the is the part following the directoryIndicator "10."

//     * 	and preceding the first forward slash (followed by the suffix)

//     * @param suffix the suffix is the part of the DOI following the first forward slash. It is provided

//     * by the registrant

//     */

//    private ORCID(String registrantCode, String suffix) {

//    	//preliminary until prefix_registrantCode and suffix validation is implemented

//		this("10." + registrantCode + "/" + suffix);

//

//		//use only after validation of both parts

////		this.prefix_registrantCode = registrantCode;

////		this.suffix = suffix;

//	}

    private ORCID(String doiString) {

		parseOrcidString(doiString);

	}

//************************************ GETTER ***********************************/

	/**

	 * The pure number representation, including the checksum (this maybe 'X'

	 * so it's not only digits

	 * @return

	 */

	public String getDigitsOnly() {

		return baseNumber+checkSum;

	}

// ********************************************* PARSER *******************************/

	private static Pattern orcidPattern = Pattern.compile("^(\\d{4}("+UTF8.ANY_DASH_RE()+")?){3}\\d{3}[0-9Xx]?$");

	private void parseOrcidString(String orcid){

		if (StringUtils.isBlank(orcid)){

			throw new IllegalArgumentException("ORCID string must not be null or blank");

		}

		orcid = orcid.trim();

		if (orcid.startsWith("http:") ){

		    orcid = orcid.replaceFirst("http:", "https:").trim();  //https is the current display standard

		}

		//replace URI prefix

		if (orcid.startsWith(HTTP_ORCID_ORG)){

			orcid = orcid.replaceFirst(HTTP_ORCID_ORG, "");

		}else if (orcid.startsWith(ORCID_ORG)){

		    orcid = orcid.replaceFirst(ORCID_ORG, "");

        }

		//now we should have the pure orcid

		if (orcid.length() != 15 && orcid.length() != 16 && orcid.length() != 18 && orcid.length() != 19){

			//for persistence reason we currently restrict the length of DOIs to 1000

			throw new IllegalArgumentException("ORCIDs must have exactly 16 digits. 3 dashes ('-') may be included after each group of 4 digits.");

		}

		Matcher matcher = orcidPattern.matcher(orcid);

		if (!matcher.find()){

            throw new IllegalArgumentException("ORCID can not be parsed. It must have exactly 16 digits. 3 dashes ('-') may be included after each group of 4 digits.");

		}

		orcid = orcid.replaceAll(UTF8.ANY_DASH_RE(), "");

		if (orcid.length() == 16){

	        this.baseNumber = orcid.substring(0, 15);

		    this.checkSum = orcid.substring(15);

		    if (!checkDigit(baseNumber).equals(checkSum)){

		        throw new IllegalArgumentException("ORCID checksum not correct (last digit is checksum, see https://support.orcid.org/hc/en-us/articles/360006897674-Structure-of-the-ORCID-Identifier).");

		    }

		}else{

		    this.baseNumber = orcid;

		    this.checkSum = checkDigit(baseNumber);

		}

	}

	private String makeOrcid(){

		return baseNumber.substring(0,4) + "-" + baseNumber.substring(4,8) + "-"

		        + baseNumber.substring(8,12) + "-" + baseNumber.substring(12,15) + checkSum;

	}

	public String asURI(){

		return HTTP_ORCID_ORG + makeOrcid();

	}

	/**

     * Generates check digit as per ISO 7064 11,2.

     * (code from https://support.orcid.org/hc/en-us/articles/360006897674)

     */

	public String checkDigit(){

	    return checkDigit(baseNumber);

	}

	/**

	  * @see #checkDigit()

	  * @param baseDigits the base digits without the checkSum digit

	  */

	private static String checkDigit(String baseDigits) {

	    int total = 0;

	    for (int i = 0; i < baseDigits.length(); i++) {

	        int digit = Character.getNumericValue(baseDigits.charAt(i));

	        total = (total + digit) * 2;

	    }

	    int remainder = total % 11;

	    int result = (12 - remainder) % 11;

	    return result == 10 ? "X" : String.valueOf(result);

	}

//************************************************* toString/equals /hashCode *********************/

	@Override

	public int hashCode() {

		if (hashCode == -1) {

            hashCode = 31 * baseNumber.hashCode();

        }

        return hashCode;

	}

	@Override

	public boolean equals(Object obj) {

		if (obj instanceof ORCID){

			return this.baseNumber.equals(((ORCID)obj).baseNumber) &&

			        this.checkSum.equals(((ORCID)obj).checkSum);

		}

		return false;

	}

	@Override

	public String toString(){

		return asURI();

	}

}