/*
    *    Copyright 2009-2024 the original author or authors.
    *
    *    Licensed 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
    *
    *       https://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.ibatis.scripting.xmltags;
  
  import java.lang.reflect.Array;
  import java.math.BigDecimal;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.ibatis.builder.BuilderException;
  
  /**
   * @author Clinton Begin
   */
  public class ExpressionEvaluator {
  
    public static final ExpressionEvaluator INSTANCE = new ExpressionEvaluator();
  
    public boolean evaluateBoolean(String expression, Object parameterObject) {
      Object value = OgnlCache.getValue(expression, parameterObject);
      if (value instanceof Boolean) {
        return (Boolean) value;
      }
      if (value instanceof Number) {
        return new BigDecimal(String.valueOf(value)).compareTo(BigDecimal.ZERO) != 0;
      }
      return value != null;
    }
  
    /**
     * @deprecated Since 3.5.9, use the {@link #evaluateIterable(String, Object, boolean)}.
     */
    @Deprecated
    public Iterable<?> evaluateIterable(String expression, Object parameterObject) {
      return evaluateIterable(expression, parameterObject, false);
    }
  
    /**
     * @since 3.5.9
     */
    public Iterable<?> evaluateIterable(String expression, Object parameterObject, boolean nullable) {
      Object value = OgnlCache.getValue(expression, parameterObject);
      if (value == null) {
        if (nullable) {
          return null;
        }
        throw new BuilderException("The expression '" + expression + "' evaluated to a null value.");
      }
      if (value instanceof Iterable) {
        return (Iterable<?>) value;
      }
      if (value.getClass().isArray()) {
        // the array may be primitive, so Arrays.asList() may throw
        // a ClassCastException (issue 209). Do the work manually
        // Curse primitives! :) (JGB)
        int size = Array.getLength(value);
        List<Object> answer = new ArrayList<>();
        for (int i = 0; i < size; i++) {
          Object o = Array.get(value, i);
          answer.add(o);
        }
        return answer;
      }
      if (value instanceof Map) {
        return ((Map) value).entrySet();
      }
      throw new BuilderException(
          "Error evaluating expression '" + expression + "'.  Return value (" + value + ") was not iterable.");
    }
  
  }