/*
*
* 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.qpid.server.store.derby;


import static org.apache.qpid.server.store.jdbc.AbstractJDBCConfigurationStore.State.CLOSED;
import static org.apache.qpid.server.store.jdbc.AbstractJDBCConfigurationStore.State.CONFIGURED;

import java.io.File;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.qpid.server.model.ConfiguredObject;
import org.apache.qpid.server.store.DurableConfigurationStore;
import org.apache.qpid.server.store.FileBasedSettings;
import org.apache.qpid.server.store.MessageStore;
import org.apache.qpid.server.store.MessageStoreProvider;
import org.apache.qpid.server.store.StoreException;
import org.apache.qpid.server.store.jdbc.AbstractJDBCConfigurationStore;
import org.apache.qpid.server.store.jdbc.AbstractJDBCPreferenceStore;
import org.apache.qpid.server.store.preferences.PreferenceStore;
import org.apache.qpid.server.util.FileUtils;

/**
 * Implementation of a DurableConfigurationStore backed by Apache Derby
 * that also provides a MessageStore.A
 */
public class DerbyConfigurationStore extends AbstractJDBCConfigurationStore
        implements MessageStoreProvider, DurableConfigurationStore
{
    private static final Logger LOGGER = LoggerFactory.getLogger(DerbyConfigurationStore.class);


    private final ProvidedDerbyMessageStore _providedMessageStore = new ProvidedDerbyMessageStore();
    private final ProvidedPreferenceStore _providedPreferenceStore = new ProvidedPreferenceStore();

    private String _connectionURL;

    private ConfiguredObject<?> _parent;
    private final Class<? extends ConfiguredObject> _rootClass;

    public DerbyConfigurationStore(final Class<? extends ConfiguredObject> rootClass)
    {
        _rootClass = rootClass;
    }

    @Override
    public void init(ConfiguredObject<?> parent)
            throws StoreException
    {
        changeState(CLOSED, CONFIGURED);
        {
            _parent = parent;
            DerbyUtils.loadDerbyDriver();

            _connectionURL = DerbyUtils.createConnectionUrl(parent.getName(), ((FileBasedSettings)_parent).getStorePath());

            createOrOpenConfigurationStoreDatabase();

        }
    }

    @Override
    public void upgradeStoreStructure() throws StoreException
    {
        upgradeIfNecessary(_parent);
    }

    @Override
    public Connection getConnection() throws SQLException
    {
        return DriverManager.getConnection(_connectionURL);
    }

    @Override
    public void closeConfigurationStore() throws StoreException
    {
        if (_providedMessageStore.isMessageStoreOpen())
        {
            throw new IllegalStateException("Cannot close the store as the provided message store is still open");
        }
       
        doIfNotState(CLOSED, new Runnable() 
                             {
                                 @Override
                                 public void run()
                                 {
                                     try
                                     {
                                         DerbyUtils.shutdownDatabase(_connectionURL);
                                     }
                                     catch (SQLException e)
                                     {
                                         throw new StoreException("Error closing configuration store", e);
                                     }

                                 }
                             }); 
        setState(CLOSED);

    }

    @Override
    protected String getSqlBlobType()
    {
        return "blob";
    }

    @Override
    protected String getSqlBlobStorage(String columnName)
    {
        return "";
    }

    @Override
    protected String getSqlVarBinaryType(int size)
    {
        return "varchar("+size+") for bit data";
    }

    @Override
    protected String getSqlBigIntType()
    {
        return "bigint";
    }

    @Override
    protected String getBlobAsString(ResultSet rs, int col) throws SQLException
    {
        return DerbyUtils.getBlobAsString(rs, col);
    }

    @Override
    public void onDelete(ConfiguredObject<?> parent)
    {
        if (_providedMessageStore.isMessageStoreOpen())
        {
            throw new IllegalStateException("Cannot delete the store as the provided message store is still open");
        }

        FileBasedSettings fileBasedSettings = (FileBasedSettings) parent;
        String storePath = fileBasedSettings.getStorePath();

        if (!DerbyUtils.MEMORY_STORE_LOCATION.equals(storePath))
        {
            if (storePath != null)
            {
                LOGGER.debug("Deleting store {}", storePath);

                File configFile = new File(storePath);
                if (!FileUtils.delete(configFile, true))
                {
                    LOGGER.info("Failed to delete the store at location " + storePath);
                }
            }
        }
    }

    @Override
    public MessageStore getMessageStore()
    {
        return _providedMessageStore;
    }

    public PreferenceStore getPreferenceStore()
    {
        return _providedPreferenceStore;
    }


    @Override
    protected boolean tableExists(final String tableName, final Connection conn) throws SQLException
    {
        return DerbyUtils.tableExists(tableName, conn);
    }

    @Override
    protected Logger getLogger()
    {
        return LOGGER;
    }

    private class ProvidedDerbyMessageStore extends AbstractDerbyMessageStore
    {
        @Override
        protected void doOpen(final ConfiguredObject<?> parent)
        {
            // Nothing to do, store provided by DerbyConfigurationStore
        }

        @Override
        public Connection getConnection() throws SQLException
        {
            checkMessageStoreOpen();
            return DerbyConfigurationStore.this.getConnection();
        }

        @Override
        protected void doClose()
        {
            // Nothing to do, store provided by DerbyConfigurationStore
        }

        @Override
        public String getStoreLocation()
        {
            return ((FileBasedSettings)(DerbyConfigurationStore.this._parent)).getStorePath();
        }

        @Override
        public File getStoreLocationAsFile()
        {
            return DerbyUtils.isInMemoryDatabase(getStoreLocation()) ? null : new File(getStoreLocation());
        }

        @Override
        public void onDelete(final ConfiguredObject<?> parent)
        {
            if (isMessageStoreOpen())
            {
                throw new IllegalStateException("Cannot delete the store as store is still open");
            }

            try(Connection connection = DerbyConfigurationStore.this.getConnection())
            {
                onDelete(connection);
            }
            catch (SQLException e)
            {
                throw new StoreException("Cannot get connection to perform deletion", e);
            }
        }

        @Override
        protected Logger getLogger()
        {
            return DerbyConfigurationStore.this.getLogger();
        }
    }

    private class ProvidedPreferenceStore extends AbstractJDBCPreferenceStore
    {
        private final Logger LOGGER = LoggerFactory.getLogger(ProvidedPreferenceStore.class);

        @Override
        protected Logger getLogger()
        {
            return LOGGER;
        }

        @Override
        protected Connection getConnection() throws SQLException
        {
            return DerbyConfigurationStore.this.getConnection();
        }

        @Override
        protected String getSqlBlobType()
        {
            return "blob";
        }

        @Override
        protected String getBlobAsString(final ResultSet rs, final int col) throws SQLException
        {
            return DerbyUtils.getBlobAsString(rs, col);
        }

        @Override
        protected void doDelete()
        {
            try
            {
                dropTables(DerbyConfigurationStore.this.getConnection());
            }
            catch (SQLException e)
            {
                getLogger().warn("Could not drop preference database tables on deletion", e);
            }
        }

        @Override
        public void doClose()
        {
            // noop
        }
    }
}