package org.gcube.portlets.user.geoportaldataviewer.server.util;

/**
 * The Class URLUtil.
 *
 * @author Francesco Mangiacrapa at ISTI-CNR (francesco.mangiacrapa@isti.cnr.it)
 * 
 * Oct 29, 2020
 */
public class URLParserUtil {
	
	/**
	 * Gets the value of parameter.
	 *
	 * @param paramName the param name
	 * @param url the url
	 * @return the value of parameter
	 */
	public static String getValueOfParameter(String paramName, String url) {
//		logger.trace("finding: "+wmsParam +" into "+url);
		int index = url.toLowerCase().indexOf(paramName.toLowerCase()+"="); //ADDING CHAR "=" IN TAIL TO BE SECURE  IT IS A PARAMETER
//		logger.trace("start index of "+wmsParam+ " is: "+index);
		String value = "";
		if(index > -1){
			int start = index + paramName.length()+1; //add +1 for char '='
			String sub = url.substring(start, url.length());
			int indexOfSeparator = sub.indexOf("&");
			int end = indexOfSeparator!=-1?indexOfSeparator:sub.length();
			value = sub.substring(0, end);
		}else
			return null;

//		logger.trace("return value: "+value);
		return value;
	}
	
	
	/**
	 * Adds the parameter to query string.
	 *
	 * @param key the key
	 * @param value the value
	 * @param prefixAmpersand the prefix ampersand
	 * @param suffixAmpersand the suffix ampersand
	 * @return the string
	 */
	public static String addParameterToQueryString(String key, String value, boolean prefixAmpersand, boolean suffixAmpersand) {
		
		String queryParameter = "";
		
		if(prefixAmpersand)
			queryParameter+="&";
		
		queryParameter+=key+"="+value;
		
		if(suffixAmpersand)
			queryParameter+="&";
		
		return queryParameter;
		
	}
	
	/**
	 * Extract value of parameter from URL.
	 *
	 * @param paramName the param name
	 * @param url       the url
	 * @return the string
	 */
	public static String extractValueOfParameterFromURL(String paramName, String url) {
		int index = url.toLowerCase().indexOf(paramName.toLowerCase() + "="); // ADDING CHAR "=" IN TAIL TO BE SURE THAT IT
																				// IS A PARAMETER
		String value = "";
		if (index > -1) {

			int start = index + paramName.length() + 1; // add +1 for char '='
			String sub = url.substring(start, url.length());
			int indexOfSeparator = sub.indexOf("&");
			int end = indexOfSeparator != -1 ? indexOfSeparator : sub.length();
			value = sub.substring(0, end);
		} else
			return null;

		return value;
	}


}