/*
    * 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.shardingsphere.sharding.rule.attribute;
  
  import com.cedarsoftware.util.CaseInsensitiveMap;
  import com.google.common.base.Strings;
  import org.apache.shardingsphere.infra.datanode.DataNode;
  import org.apache.shardingsphere.infra.rule.attribute.datanode.DataNodeRuleAttribute;
  import org.apache.shardingsphere.sharding.rule.ShardingTable;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  
  /**
   * Sharding data node rule attribute.
   */
  public final class ShardingDataNodeRuleAttribute implements DataNodeRuleAttribute {
      
      private final Map<String, ShardingTable> shardingTables;
      
      private final Map<String, Collection<DataNode>> tableDataNodes;
      
      public ShardingDataNodeRuleAttribute(final Map<String, ShardingTable> shardingTables) {
          this.shardingTables = shardingTables;
          tableDataNodes = createShardingTableDataNodes(shardingTables);
      }
      
      private Map<String, Collection<DataNode>> createShardingTableDataNodes(final Map<String, ShardingTable> shardingTables) {
          Map<String, Collection<DataNode>> result = new CaseInsensitiveMap<>(shardingTables.size(), 1F);
          for (ShardingTable each : shardingTables.values()) {
              result.put(each.getLogicTable(), each.getActualDataNodes());
          }
          return result;
      }
      
      @Override
      public Map<String, Collection<DataNode>> getAllDataNodes() {
          return tableDataNodes;
      }
      
      @Override
      public Collection<DataNode> getDataNodesByTableName(final String tableName) {
          return tableDataNodes.getOrDefault(tableName, Collections.emptyList());
      }
      
      @Override
      public Optional<String> findFirstActualTable(final String logicTable) {
          return findShardingTable(logicTable).map(optional -> optional.getActualDataNodes().get(0).getTableName());
      }
      
      private Optional<ShardingTable> findShardingTable(final String logicTableName) {
          return Strings.isNullOrEmpty(logicTableName) || !shardingTables.containsKey(logicTableName) ? Optional.empty() : Optional.of(shardingTables.get(logicTableName));
      }
      
      @Override
      public boolean isNeedAccumulate(final Collection<String> tables) {
          return containsShardingTable(tables);
      }
      
      private boolean containsShardingTable(final Collection<String> logicTableNames) {
          for (String each : logicTableNames) {
              if (isShardingTable(each)) {
                  return true;
              }
          }
          return false;
      }
      
      private boolean isShardingTable(final String logicTableName) {
          return shardingTables.containsKey(logicTableName);
      }
      
      @Override
      public Optional<String> findLogicTableByActualTable(final String actualTable) {
          return findShardingTableByActualTable(actualTable).map(ShardingTable::getLogicTable);
      }
      
      private Optional<ShardingTable> findShardingTableByActualTable(final String actualTableName) {
          for (ShardingTable each : shardingTables.values()) {
              if (each.isExisted(actualTableName)) {
                  return Optional.of(each);
             }
         }
         return Optional.empty();
     }
     
     @Override
     public Optional<String> findActualTableByCatalog(final String catalog, final String logicTable) {
         return findShardingTable(logicTable).flatMap(optional -> findActualTableFromActualDataNode(catalog, optional.getActualDataNodes()));
     }
     
     private Optional<String> findActualTableFromActualDataNode(final String catalog, final List<DataNode> actualDataNodes) {
         return actualDataNodes.stream().filter(each -> each.getDataSourceName().equalsIgnoreCase(catalog)).findFirst().map(DataNode::getTableName);
     }
 }