/*
 *  Copyright 2004 Clinton Begin
 *
 *  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
 *
 *      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 com.ibatis.sqlmap.engine.exchange;


import com.ibatis.sqlmap.engine.accessplan.AccessPlan;
import com.ibatis.sqlmap.engine.accessplan.AccessPlanFactory;
import com.ibatis.sqlmap.engine.mapping.parameter.ParameterMap;
import com.ibatis.sqlmap.engine.mapping.parameter.ParameterMapping;
import com.ibatis.sqlmap.engine.mapping.result.ResultMap;
import com.ibatis.sqlmap.engine.mapping.result.ResultMapping;
import com.ibatis.sqlmap.engine.mapping.result.ResultObjectFactoryUtil;
import com.ibatis.sqlmap.engine.scope.ErrorContext;
import com.ibatis.sqlmap.engine.scope.RequestScope;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * DataExchange implementation for beans
 */
public class JavaBeanDataExchange extends BaseDataExchange implements DataExchange {

  private static final Object[] NO_DATA = new Object[0];

  private AccessPlan resultPlan;
  private AccessPlan parameterPlan;
  private AccessPlan outParamPlan;

  protected JavaBeanDataExchange(DataExchangeFactory dataExchangeFactory) {
    super(dataExchangeFactory);
  }

  /**
   * Initializes the data exchange instance.
   *
   * @param properties
   */
  public void initialize(Map properties) {
    Object map = properties.get("map");
    if (map instanceof ParameterMap) {
      ParameterMap parameterMap = (ParameterMap) map;
      if (parameterMap != null) {
        ParameterMapping[] parameterMappings = parameterMap.getParameterMappings();
        String[] parameterPropNames = new String[parameterMappings.length];
        for (int i = 0; i < parameterPropNames.length; i++) {
          parameterPropNames[i] = parameterMappings[i].getPropertyName();
        }
        parameterPlan = AccessPlanFactory.getAccessPlan(parameterMap.getParameterClass(), parameterPropNames);

        // OUTPUT PARAMS
        List outParamList = new ArrayList();
        for (int i = 0; i < parameterPropNames.length; i++) {
          if (parameterMappings[i].isOutputAllowed()) {
            outParamList.add(parameterMappings[i].getPropertyName());
          }
        }
        String[] outParams = (String[]) outParamList.toArray(new String[outParamList.size()]);
        outParamPlan = AccessPlanFactory.getAccessPlan(parameterMap.getParameterClass(), outParams);
      }

    } else if (map instanceof ResultMap) {
      ResultMap resultMap = (ResultMap) map;
      if (resultMap != null) {
        ResultMapping[] resultMappings = resultMap.getResultMappings();
        String[] resultPropNames = new String[resultMappings.length];
        for (int i = 0; i < resultPropNames.length; i++) {
          resultPropNames[i] = resultMappings[i].getPropertyName();
        }
        resultPlan = AccessPlanFactory.getAccessPlan(resultMap.getResultClass(), resultPropNames);
      }
    }
  }

  public Object[] getData(RequestScope request, ParameterMap parameterMap, Object parameterObject) {
    if (parameterPlan != null) {
      return parameterPlan.getProperties(parameterObject);
    } else {
      return NO_DATA;
    }
  }

  public Object setData(RequestScope request, ResultMap resultMap, Object resultObject, Object[] values) {
    if (resultPlan != null) {
      Object object = resultObject;

      ErrorContext errorContext = request.getErrorContext();

      if (object == null) {
        errorContext.setMoreInfo("The error occured while instantiating the result object");
        try {
          object = ResultObjectFactoryUtil.createObjectThroughFactory(resultMap.getResultClass());
        } catch (Exception e) {
          throw new RuntimeException("JavaBeansDataExchange could not instantiate result class.  Cause: " + e, e);
        }
      }
      errorContext.setMoreInfo("The error happened while setting a property on the result object.");
      resultPlan.setProperties(object, values);
      return object;
    } else {
      return null;
    }
  }

  // Bug ibatis-12
  public Object setData(RequestScope request, ParameterMap parameterMap, Object parameterObject, Object[] values) {
    if (outParamPlan != null) {
      Object object = parameterObject;
      if (object == null) {
        try {
          object = ResultObjectFactoryUtil.createObjectThroughFactory(parameterMap.getParameterClass());
        } catch (Exception e) {
          throw new RuntimeException("JavaBeansDataExchange could not instantiate parameter class. Cause: " + e, e);
        }
      }
      values = getOutputParamValues(parameterMap.getParameterMappings(), values);
      outParamPlan.setProperties(object, values);
      return object;
    } else {
      return null;
    }
  }

  private Object[] getOutputParamValues(ParameterMapping[] mappings, Object[] values) {
    List outParamValues = new ArrayList();
    for (int i = 0; i < mappings.length; i++) {
      if (mappings[i].isOutputAllowed()) {
        outParamValues.add(values[i]);
      }
    }
    return outParamValues.toArray();
  }

}