/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.runtime.core.el.function;

import org.mule.runtime.core.api.el.ExpressionLanguageContext;
import org.mule.runtime.core.api.el.ExpressionLanguageFunction;
import org.mule.runtime.core.api.expression.ExpressionRuntimeException;
import org.mule.runtime.core.config.i18n.CoreMessages;
import org.mule.runtime.core.el.datetime.DateTime;

import java.text.ParseException;
import java.util.Calendar;
import java.util.Date;

import javax.xml.datatype.XMLGregorianCalendar;

public class DateTimeExpressionLanguageFuntion implements ExpressionLanguageFunction {

  @Override
  public Object call(Object[] params, ExpressionLanguageContext context) {
    int numParams = params.length;
    if (numParams < 1 || numParams > 3) {
      throw new IllegalArgumentException("invalid number of arguments");
    }

    if (numParams == 1) {
      Object dateParam = params[0];
      if (dateParam instanceof Date) {
        return new DateTime((Date) dateParam);
      } else if (dateParam instanceof Calendar) {
        return new DateTime((Calendar) dateParam);
      } else if (dateParam instanceof XMLGregorianCalendar) {
        return new DateTime((XMLGregorianCalendar) dateParam);
      } else {
        try {
          return new DateTime(dateParam.toString());
        } catch (RuntimeException e) {
          throw new ExpressionRuntimeException(CoreMessages.createStaticMessage("Unable to parse string as a ISO-8601 date"), e);
        }
      }
    } else {
      try {
        return new DateTime((String) params[0], (String) params[1]);
      } catch (ParseException e) {
        throw new ExpressionRuntimeException(CoreMessages
            .createStaticMessage("Unable to parse string as a date using format '" + params[1] + "''"));
      }
    }
  }
}