/*******************************************************************************
 * Copyright 2017 Bstek
 *
 * 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.bstek.ureport.build.aggregate;

import com.bstek.ureport.build.BindData;
import com.bstek.ureport.build.Context;
import com.bstek.ureport.definition.Order;
import com.bstek.ureport.definition.value.GroupItem;
import com.bstek.ureport.expression.model.Condition;
import com.bstek.ureport.expression.model.expr.dataset.DatasetExpression;
import com.bstek.ureport.model.Cell;
import com.bstek.ureport.utils.DataUtils;

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

/**
 * @author Jacky.gao
 * @since 2017年3月29日
 */
public class CustomGroupAggregate extends Aggregate {

    @Override
    public List<BindData> aggregate(DatasetExpression expr, Cell cell, Context context) {
        List<?> objList = DataUtils.fetchData(cell, context, expr.getDatasetName());
        return doAggregate(expr, cell, context, objList);
    }

    protected List<BindData> doAggregate(DatasetExpression expr, Cell cell, Context context, List<?> objList) {
        List<BindData> list = new ArrayList<>();
        List<GroupItem> groupItems = expr.getGroupItems();
        if (objList.size() == 0) {
            list.add(new BindData(""));
            return list;
        } else if (objList.size() == 1) {
            Object o = objList.get(0);
            boolean conditionResult = doCondition(expr.getCondition(), cell, o, context);
            if (!conditionResult) {
                list.add(new BindData(""));
                return list;
            }
            String itemName = groupData(groupItems, cell, context, o);
            if (itemName == null) {
                list.add(new BindData(""));
                return list;
            }
            List<Object> rowList = new ArrayList<>();
            rowList.add(o);
            list.add(new BindData(itemName, rowList));
            return list;
        }
        Map<Object, List<Object>> map = new HashMap<>();
        for (Object o : objList) {
            boolean conditionResult = doCondition(expr.getCondition(), cell, o, context);
            if (!conditionResult) {
                continue;
            }
            String itemName = groupData(groupItems, cell, context, o);
            if (itemName == null) {
                continue;
            }
            List<Object> rowList;
            if (map.containsKey(itemName)) {
                rowList = map.get(itemName);
            } else {
                rowList = new ArrayList<>();
                map.put(itemName, rowList);
                list.add(new BindData(itemName, rowList));
            }
            rowList.add(o);
        }
        if (list.size() == 0) {
            List<Object> rowList = new ArrayList<>();
            rowList.add(new HashMap<String, Object>());
            list.add(new BindData("", rowList));
        }
        if (list.size() > 1) {
            Order order = expr.getOrder();
            orderBindDataList(list, order);
        }
        return list;
    }

    private String groupData(List<GroupItem> groupItems, Cell cell, Context context, Object o) {
        for (GroupItem item : groupItems) {
            Condition condition = item.getCondition();
            boolean doCondition = doCondition(condition, cell, o, context);
            if (doCondition) {
                return item.getName();
            }
        }
        return null;
    }
}
