/*
    * 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.infra.metadata.database;
  
  import lombok.AccessLevel;
  import lombok.Getter;
  import org.apache.shardingsphere.database.connector.core.type.DatabaseType;
  import org.apache.shardingsphere.infra.config.rule.RuleConfiguration;
  import org.apache.shardingsphere.infra.config.rule.decorator.RuleConfigurationDecorator;
  import org.apache.shardingsphere.infra.exception.ShardingSpherePreconditions;
  import org.apache.shardingsphere.infra.exception.kernel.metadata.resource.storageunit.MissingRequiredStorageUnitsException;
  import org.apache.shardingsphere.infra.metadata.database.resource.ResourceMetaData;
  import org.apache.shardingsphere.infra.metadata.database.rule.RuleMetaData;
  import org.apache.shardingsphere.infra.metadata.database.schema.model.ShardingSphereSchema;
  import org.apache.shardingsphere.infra.metadata.identifier.ShardingSphereIdentifier;
  import org.apache.shardingsphere.infra.rule.ShardingSphereRule;
  import org.apache.shardingsphere.infra.rule.attribute.datanode.MutableDataNodeRuleAttribute;
  import org.apache.shardingsphere.infra.rule.attribute.datasource.DataSourceMapperRuleAttribute;
  import org.apache.shardingsphere.infra.spi.type.typed.TypedSPILoader;
  
  import javax.sql.DataSource;
  import java.util.Collection;
  import java.util.LinkedHashMap;
  import java.util.LinkedList;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Optional;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.stream.Collectors;
  
  /**
   * ShardingSphere database.
   */
  @Getter
  public final class ShardingSphereDatabase {
      
      private final String name;
      
      private final DatabaseType protocolType;
      
      private final ResourceMetaData resourceMetaData;
      
      private final RuleMetaData ruleMetaData;
      
      @Getter(AccessLevel.NONE)
      private final Map<ShardingSphereIdentifier, ShardingSphereSchema> schemas;
      
      public ShardingSphereDatabase(final String name, final DatabaseType protocolType, final ResourceMetaData resourceMetaData,
                                    final RuleMetaData ruleMetaData, final Collection<ShardingSphereSchema> schemas) {
          this.name = name;
          this.protocolType = protocolType;
          this.resourceMetaData = resourceMetaData;
          this.ruleMetaData = ruleMetaData;
          this.schemas = new ConcurrentHashMap<>(schemas.stream().collect(Collectors.toMap(each -> new ShardingSphereIdentifier(each.getName()), each -> each)));
      }
      
      /**
       * Get all schemas.
       *
       * @return all schemas
       */
      public Collection<ShardingSphereSchema> getAllSchemas() {
          return schemas.values();
      }
      
      /**
       * Judge contains schema from database or not.
       *
       * @param schemaName schema name
       * @return contains schema from database or not
       */
      public boolean containsSchema(final String schemaName) {
          return schemas.containsKey(new ShardingSphereIdentifier(schemaName));
      }
      
      /**
       * Get schema.
       *
       * @param schemaName schema name
       * @return schema
       */
      public ShardingSphereSchema getSchema(final String schemaName) {
          return schemas.get(new ShardingSphereIdentifier(schemaName));
      }
     
     /**
      * Add schema.
      *
      * @param schema schema
      */
     public void addSchema(final ShardingSphereSchema schema) {
         schemas.put(new ShardingSphereIdentifier(schema.getName()), schema);
     }
     
     /**
      * Drop schema.
      *
      * @param schemaName schema name
      */
     public void dropSchema(final String schemaName) {
         schemas.remove(new ShardingSphereIdentifier(schemaName));
     }
     
     /**
      * Judge whether is completed.
      *
      * @return is completed or not
      */
     public boolean isComplete() {
         return !ruleMetaData.getRules().isEmpty() && !resourceMetaData.getStorageUnits().isEmpty();
     }
     
     /**
      * Judge whether contains data source.
      *
      * @return contains data source or not
      */
     public boolean containsDataSource() {
         return !resourceMetaData.getStorageUnits().isEmpty();
     }
     
     /**
      * Reload rules.
      */
     public synchronized void reloadRules() {
         Collection<ShardingSphereRule> toBeReloadedRules = ruleMetaData.getRules().stream()
                 .filter(each -> each.getAttributes().findAttribute(MutableDataNodeRuleAttribute.class).isPresent()).collect(Collectors.toList());
         RuleConfiguration ruleConfig = toBeReloadedRules.stream().map(ShardingSphereRule::getConfiguration).findFirst().orElse(null);
         Collection<ShardingSphereRule> rules = new LinkedList<>(ruleMetaData.getRules());
         toBeReloadedRules.stream().findFirst().ifPresent(optional -> {
             rules.removeAll(toBeReloadedRules);
             Map<String, DataSource> dataSources = resourceMetaData.getStorageUnits().entrySet().stream()
                     .collect(Collectors.toMap(Entry::getKey, entry -> entry.getValue().getDataSource(), (oldValue, currentValue) -> oldValue, LinkedHashMap::new));
             rules.add(optional.getAttributes().getAttribute(MutableDataNodeRuleAttribute.class).reloadRule(ruleConfig, name, dataSources, rules));
         });
         ruleMetaData.getRules().clear();
         ruleMetaData.getRules().addAll(rules);
     }
     
     /**
      * Check storage units existed.
      *
      * @param storageUnitNames storage unit names
      */
     public void checkStorageUnitsExisted(final Collection<String> storageUnitNames) {
         Collection<String> notExistedDataSources = resourceMetaData.getNotExistedDataSources(storageUnitNames);
         Collection<String> logicDataSources = ruleMetaData.getAttributes(DataSourceMapperRuleAttribute.class).stream()
                 .flatMap(each -> each.getDataSourceMapper().keySet().stream()).collect(Collectors.toSet());
         notExistedDataSources.removeIf(logicDataSources::contains);
         ShardingSpherePreconditions.checkMustEmpty(notExistedDataSources, () -> new MissingRequiredStorageUnitsException(name, notExistedDataSources));
     }
     
     /**
      * Decorate rule configuration.
      *
      * @param ruleConfig rule configuration
      * @return decorated rule configuration
      */
     @SuppressWarnings({"unchecked", "rawtypes"})
     public RuleConfiguration decorateRuleConfiguration(final RuleConfiguration ruleConfig) {
         Optional<RuleConfigurationDecorator> decorator = TypedSPILoader.findService(RuleConfigurationDecorator.class, ruleConfig.getClass());
         if (!decorator.isPresent()) {
             return ruleConfig;
         }
         Map<String, DataSource> dataSources = resourceMetaData.getStorageUnits().entrySet().stream()
                 .collect(Collectors.toMap(Entry::getKey, entry -> entry.getValue().getDataSource(), (oldValue, currentValue) -> oldValue, LinkedHashMap::new));
         return decorator.get().decorate(name, dataSources, ruleMetaData.getRules(), ruleConfig);
     }
 }