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*/

package com.google.refine.expr.functions.strings;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.Properties;

import org.apache.commons.text.StringEscapeUtils;

import com.google.refine.expr.EvalError;
import com.google.refine.grel.ControlFunctionRegistry;
import com.google.refine.grel.Function;

public class Unescape implements Function {

    @Override
    public Object call(Properties bindings, Object[] args) {
        if (args.length == 2) {
            Object o1 = args[0];
            Object o2 = args[1];
            if (o1 != null && o2 != null && o1 instanceof String && o2 instanceof String) {
                String s = (String) o1;
                String mode = ((String) o2).toLowerCase();
                if ("html".equals(mode)) {
                    return StringEscapeUtils.unescapeHtml4(s);
                } else if ("xml".equals(mode)) {
                    return StringEscapeUtils.unescapeXml(s);
                } else if ("csv".equals(mode)) {
                    return StringEscapeUtils.unescapeCsv(s);
                } else if ("javascript".equals(mode)) {
                    return StringEscapeUtils.unescapeEcmaScript(s);
                } else if ("url".equals(mode)) {
                    try {
                        return URLDecoder.decode(s,"UTF-8");
                    } catch (UnsupportedEncodingException e) {}
                } else {
                    return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " does not recognize mode '" + mode + "'.");
                }
            }
        }
        return null;
    }
    
    @Override
    public String getDescription() {
        return "Unescapes all escaped parts of the string depending on the given escaping mode.";
    }
    
    @Override
    public String getParams() {
        return "string s, string mode ['html','xml','csv','url','javascript']";
    }
    
    @Override
    public String getReturns() {
        return "string";
    }
}
