content: /*
   * Copyright (c) 2013. wyouflf (wyouflf@gmail.com)
   *
   * 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.lidroid.xutils.db.table;
  
  import android.database.Cursor;
  import com.lidroid.xutils.db.converter.ColumnConverter;
  import com.lidroid.xutils.db.converter.ColumnConverterFactory;
  import com.lidroid.xutils.db.sqlite.ColumnDbType;
  import com.lidroid.xutils.db.sqlite.ForeignLazyLoader;
  import com.lidroid.xutils.exception.DbException;
  import com.lidroid.xutils.util.LogUtils;
  
  import java.lang.reflect.Field;
  import java.util.List;
  
  public class Foreign extends Column {
  
      private final String foreignColumnName;
      private final ColumnConverter foreignColumnConverter;
  
      /* package */ Foreign(Class<?> entityType, Field field) {
          super(entityType, field);
  
          foreignColumnName = ColumnUtils.getForeignColumnNameByField(field);
          Class<?> foreignColumnType =
                  TableUtils.getColumnOrId(getForeignEntityType(), foreignColumnName).columnField.getType();
          foreignColumnConverter = ColumnConverterFactory.getColumnConverter(foreignColumnType);
      }
  
      public String getForeignColumnName() {
          return foreignColumnName;
      }
  
      public Class<?> getForeignEntityType() {
          return ColumnUtils.getForeignEntityType(this);
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public void setValue2Entity(Object entity, Cursor cursor, int index) {
          Object fieldValue = foreignColumnConverter.getFieldValue(cursor, index);
          if (fieldValue == null) return;
  
          Object value = null;
          Class<?> columnType = columnField.getType();
          if (columnType.equals(ForeignLazyLoader.class)) {
              value = new ForeignLazyLoader(this, fieldValue);
          } else if (columnType.equals(List.class)) {
              try {
                  value = new ForeignLazyLoader(this, fieldValue).getAllFromDb();
              } catch (DbException e) {
                  LogUtils.e(e.getMessage(), e);
              }
          } else {
              try {
                  value = new ForeignLazyLoader(this, fieldValue).getFirstFromDb();
              } catch (DbException e) {
                  LogUtils.e(e.getMessage(), e);
              }
          }
  
          if (setMethod != null) {
              try {
                  setMethod.invoke(entity, value);
              } catch (Throwable e) {
                  LogUtils.e(e.getMessage(), e);
              }
          } else {
              try {
                  this.columnField.setAccessible(true);
                  this.columnField.set(entity, value);
              } catch (Throwable e) {
                  LogUtils.e(e.getMessage(), e);
              }
          }
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public Object getColumnValue(Object entity) {
          Object fieldValue = getFieldValue(entity);
          Object columnValue = null;
  
          if (fieldValue != null) {
              Class<?> columnType = columnField.getType();
              if (columnType.equals(ForeignLazyLoader.class)) {
                  columnValue = ((ForeignLazyLoader) fieldValue).getColumnValue();
              } else if (columnType.equals(List.class)) {
                  try {
                      List<?> foreignEntities = (List<?>) fieldValue;
                      if (foreignEntities.size() > 0) {
  
                          Class<?> foreignEntityType = ColumnUtils.getForeignEntityType(this);
                          Column column = TableUtils.getColumnOrId(foreignEntityType, foreignColumnName);
                          columnValue = column.getColumnValue(foreignEntities.get(0));
  
                          // 仅自动关联外键
                          Table table = this.getTable();
                          if (table != null && column instanceof Id) {
                              for (Object foreignObj : foreignEntities) {
                                  Object idValue = column.getColumnValue(foreignObj);
                                  if (idValue == null) {
                                      table.db.saveOrUpdate(foreignObj);
                                  }
                              }
                          }
  
                          columnValue = column.getColumnValue(foreignEntities.get(0));
                      }
                  } catch (Throwable e) {
                      LogUtils.e(e.getMessage(), e);
                  }
              } else {
                  try {
                      Column column = TableUtils.getColumnOrId(columnType, foreignColumnName);
                      columnValue = column.getColumnValue(fieldValue);
  
                      Table table = this.getTable();
                      if (table != null && columnValue == null && column instanceof Id) {
                          table.db.saveOrUpdate(fieldValue);
                      }
  
                      columnValue = column.getColumnValue(fieldValue);
                  } catch (Throwable e) {
                      LogUtils.e(e.getMessage(), e);
                  }
              }
          }
  
          return columnValue;
      }
  
      @Override
      public ColumnDbType getColumnDbType() {
          return foreignColumnConverter.getColumnDbType();
      }
  
      /**
       * It always return null.
       *
       * @return null
       */
      @Override
      public Object getDefaultValue() {
          return null;
      }
  }
  