/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License. You may obtain a
 * copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package org.apache.geode.cache.query.internal;

import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.HashSet;
import java.util.Set;

import org.apache.geode.cache.query.FunctionDomainException;
import org.apache.geode.cache.query.NameResolutionException;
import org.apache.geode.cache.query.QueryInvalidException;
import org.apache.geode.cache.query.QueryInvocationTargetException;
import org.apache.geode.cache.query.QueryService;
import org.apache.geode.cache.query.TypeMismatchException;
import org.apache.geode.pdx.internal.PdxString;

/**
 * Class Description
 *
 * @version $Revision: 1.1 $
 */

public class Functions {
  public static final int ELEMENT = 1;

  public static Object nvl(CompiledValue arg1, CompiledValue arg2, ExecutionContext context)
      throws FunctionDomainException, TypeMismatchException, NameResolutionException,
      QueryInvocationTargetException {
    Object value = arg1.evaluate(context);
    if (value == null) {
      return arg2.evaluate(context);
    }
    return value;
  }

  public static Date to_date(CompiledValue cv1, CompiledValue cv2, ExecutionContext context)
      throws FunctionDomainException, TypeMismatchException, NameResolutionException,
      QueryInvocationTargetException {
    Object value1 = cv1.evaluate(context);
    Object value2 = cv2.evaluate(context);
    if (!(value1 instanceof String) || !(value2 instanceof String)) {
      throw new QueryInvalidException(
          "Parameters to the to_date function should be strictly simple strings");
    }
    String dateStr = (String) value1;
    String format = (String) value2;
    Date dt = null;
    try {
      // Removed the following line so that to data format conforms to
      // SimpleDateFormat exactly (bug 39144)
      // format = ((format.replaceAll("Y", "y")).replaceAll("m", "M")).replaceAll("D", "d");

      /*
       * if((format.indexOf("MM") == -1 && format.indexOf("M") == -1) || (format. indexOf("dd") ==
       * -1 && format.indexOf("d") == -1) || (format.indexOf("yyyy") == -1 && format.indexOf("yy")
       * == -1)) { throw new QueryInvalidException("Malformed date format string"); }
       * if(format.indexOf("MMM") != -1 || format.indexOf("ddd") != -1 || format.in dexOf("yyyyy")
       * != -1) { throw new QueryInvalidException("Malformed date format string"); }
       */

      SimpleDateFormat sdf1 = new SimpleDateFormat(format);
      dt = sdf1.parse(dateStr);

    } catch (Exception ex) {
      throw new QueryInvalidException(
          String.format("Malformed date format string as the format is %s",
              format),
          ex);
    }
    return dt;
  }
  // end of to_date

  public static Object element(Object arg, ExecutionContext context)
      throws FunctionDomainException, TypeMismatchException {
    if (arg == null || arg == QueryService.UNDEFINED)
      return QueryService.UNDEFINED;

    if (arg instanceof Collection) {
      Collection c = (Collection) arg;
      // for remote distinct queries, the result of sub query could contain a
      // mix of String and PdxString which could be duplicates, so convert all
      // PdxStrings to String
      if (context.isDistinct() && ((DefaultQuery) context.getQuery()).isRemoteQuery()) {
        Set tempResults = new HashSet();
        for (Object o : c) {
          if (o instanceof PdxString) {
            o = ((PdxString) o).toString();
          }
          tempResults.add(o);
        }
        c.clear();
        c.addAll(tempResults);
        tempResults = null;
      }
      checkSingleton(c.size());
      return c.iterator().next();
    }

    // not a Collection, must be an array
    Class clazz = arg.getClass();
    if (!clazz.isArray())
      throw new TypeMismatchException(
          String.format("The 'element' function cannot be applied to an object of type ' %s '",
              clazz.getName()));

    // handle arrays
    if (arg instanceof Object[]) {
      Object[] a = (Object[]) arg;
      if (((DefaultQuery) context.getQuery()).isRemoteQuery() && context.isDistinct()) {
        for (int i = 0; i < a.length; i++) {
          if (a[i] instanceof PdxString) {
            a[i] = ((PdxString) a[i]).toString();
          }
        }
      }
      checkSingleton(a.length);
      return a[0];
    }

    if (arg instanceof int[]) {
      int[] a = (int[]) arg;
      checkSingleton(a.length);
      return Integer.valueOf(a[0]);
    }

    if (arg instanceof long[]) {
      long[] a = (long[]) arg;
      checkSingleton(a.length);
      return Long.valueOf(a[0]);
    }


    if (arg instanceof boolean[]) {
      boolean[] a = (boolean[]) arg;
      checkSingleton(a.length);
      return Boolean.valueOf(a[0]);
    }

    if (arg instanceof byte[]) {
      byte[] a = (byte[]) arg;
      checkSingleton(a.length);
      return Byte.valueOf(a[0]);
    }

    if (arg instanceof char[]) {
      char[] a = (char[]) arg;
      checkSingleton(a.length);
      return new Character(a[0]);
    }

    if (arg instanceof double[]) {
      double[] a = (double[]) arg;
      checkSingleton(a.length);
      return Double.valueOf(a[0]);
    }

    if (arg instanceof float[]) {
      float[] a = (float[]) arg;
      checkSingleton(a.length);
      return new Float(a[0]);
    }


    if (arg instanceof short[]) {
      short[] a = (short[]) arg;
      checkSingleton(a.length);
      return new Short(a[0]);
    }

    // did I miss something?
    throw new TypeMismatchException(
        String.format("The 'element' function cannot be applied to an object of type ' %s '",
            clazz.getName()));
  }

  private static void checkSingleton(int size) throws FunctionDomainException {
    if (size != 1)
      throw new FunctionDomainException(
          String.format("element() applied to parameter of size %s",
              Integer.valueOf(size)));
  }


}