/*
 * Copyright 2002-2014 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.batch.core.repository.support;

import java.lang.reflect.Field;
import java.sql.Types;
import javax.sql.DataSource;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.batch.core.repository.ExecutionContextSerializer;
import org.springframework.batch.core.repository.dao.AbstractJdbcBatchMetadataDao;
import org.springframework.batch.core.repository.dao.ExecutionContextDao;
import org.springframework.batch.core.repository.dao.Jackson2ExecutionContextStringSerializer;
import org.springframework.batch.core.repository.dao.JdbcExecutionContextDao;
import org.springframework.batch.core.repository.dao.JdbcJobExecutionDao;
import org.springframework.batch.core.repository.dao.JdbcJobInstanceDao;
import org.springframework.batch.core.repository.dao.JdbcStepExecutionDao;
import org.springframework.batch.core.repository.dao.JobExecutionDao;
import org.springframework.batch.core.repository.dao.JobInstanceDao;
import org.springframework.batch.core.repository.dao.StepExecutionDao;
import org.springframework.batch.item.database.support.DataFieldMaxValueIncrementerFactory;
import org.springframework.batch.item.database.support.DefaultDataFieldMaxValueIncrementerFactory;
import org.springframework.batch.support.DatabaseType;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.jdbc.core.JdbcOperations;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.support.lob.DefaultLobHandler;
import org.springframework.jdbc.support.lob.LobHandler;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

import static org.springframework.batch.support.DatabaseType.SYBASE;

/**
 * A {@link FactoryBean} that automates the creation of a
 * {@link SimpleJobRepository} using JDBC DAO implementations which persist
 * batch metadata in database. Requires the user to describe what kind of
 * database they are using.
 *
 * @author Ben Hale
 * @author Lucas Ward
 * @author Dave Syer
 * @author Michael Minella
 */
public class JobRepositoryFactoryBean extends AbstractJobRepositoryFactoryBean implements InitializingBean {

        protected static final Log logger = LogFactory.getLog(JobRepositoryFactoryBean.class);

        private DataSource dataSource;

        private JdbcOperations jdbcOperations;

        private String databaseType;

        private String tablePrefix = AbstractJdbcBatchMetadataDao.DEFAULT_TABLE_PREFIX;

        private DataFieldMaxValueIncrementerFactory incrementerFactory;

        private int maxVarCharLength = AbstractJdbcBatchMetadataDao.DEFAULT_EXIT_MESSAGE_LENGTH;

        private LobHandler lobHandler;

        private ExecutionContextSerializer serializer;

        private Integer lobType;

        /**
         * @param type a value from the {@link java.sql.Types} class to indicate the type to use for a CLOB
         */
        public void setClobType(int type) {
                this.lobType = type;
        }

        /**
         * A custom implementation of the {@link ExecutionContextSerializer}.
         * The default, if not injected, is the {@link Jackson2ExecutionContextStringSerializer}.
         *
         * @param serializer used to serialize/deserialize {@link org.springframework.batch.item.ExecutionContext}
         * @see ExecutionContextSerializer
         */
        public void setSerializer(ExecutionContextSerializer serializer) {
                this.serializer = serializer;
        }

        /**
         * A special handler for large objects. The default is usually fine, except
         * for some (usually older) versions of Oracle. The default is determined
         * from the data base type.
         *
         * @param lobHandler the {@link LobHandler} to set
         *
         * @see LobHandler
         */
        public void setLobHandler(LobHandler lobHandler) {
                this.lobHandler = lobHandler;
        }

        /**
         * Public setter for the length of long string columns in database. Do not
         * set this if you haven't modified the schema. Note this value will be used
         * for the exit message in both {@link JdbcJobExecutionDao} and
         * {@link JdbcStepExecutionDao} and also the short version of the execution
         * context in {@link JdbcExecutionContextDao} . For databases with
         * multi-byte character sets this number can be smaller (by up to a factor
         * of 2 for 2-byte characters) than the declaration of the column length in
         * the DDL for the tables.
         *
         * @param maxVarCharLength the exitMessageLength to set
         */
        public void setMaxVarCharLength(int maxVarCharLength) {
                this.maxVarCharLength = maxVarCharLength;
        }

        /**
         * Public setter for the {@link DataSource}.
         * @param dataSource a {@link DataSource}
         */
        public void setDataSource(DataSource dataSource) {
                this.dataSource = dataSource;
        }
        
        /**
         * Public setter for the {@link JdbcOperations}. If this property is not set explicitly,
         * a new {@link JdbcTemplate} will be created for the configured DataSource by default.
         * @param jdbcOperations a {@link JdbcOperations}
         */
        public void setJdbcOperations(JdbcOperations jdbcOperations) {
                this.jdbcOperations = jdbcOperations;
        }

        /**
         * Sets the database type.
         * @param dbType as specified by
         * {@link DefaultDataFieldMaxValueIncrementerFactory}
         */
        public void setDatabaseType(String dbType) {
                this.databaseType = dbType;
        }

        /**
         * Sets the table prefix for all the batch meta-data tables.
         * @param tablePrefix prefix prepended to batch meta-data tables
         */
        public void setTablePrefix(String tablePrefix) {
                this.tablePrefix = tablePrefix;
        }

        public void setIncrementerFactory(DataFieldMaxValueIncrementerFactory incrementerFactory) {
                this.incrementerFactory = incrementerFactory;
        }

        @Override
        public void afterPropertiesSet() throws Exception {

                Assert.notNull(dataSource, "DataSource must not be null.");

                if (jdbcOperations == null) {
                        jdbcOperations = new JdbcTemplate(dataSource);  
                }               

                if (incrementerFactory == null) {
                        incrementerFactory = new DefaultDataFieldMaxValueIncrementerFactory(dataSource);
                }

                if (databaseType == null) {
                        databaseType = DatabaseType.fromMetaData(dataSource).name();
                        logger.info("No database type set, using meta data indicating: " + databaseType);
                }

                if (lobHandler == null && databaseType.equalsIgnoreCase(DatabaseType.ORACLE.toString())) {
                        lobHandler = new DefaultLobHandler();
                }

                if(serializer == null) {
                        Jackson2ExecutionContextStringSerializer defaultSerializer = new Jackson2ExecutionContextStringSerializer();

                        serializer = defaultSerializer;
                }

                Assert.isTrue(incrementerFactory.isSupportedIncrementerType(databaseType), "'" + databaseType
                                + "' is an unsupported database type.  The supported database types are "
                                + StringUtils.arrayToCommaDelimitedString(incrementerFactory.getSupportedIncrementerTypes()));

                if(lobType != null) {
                        Assert.isTrue(isValidTypes(lobType), "lobType must be a value from the java.sql.Types class");
                }

                super.afterPropertiesSet();
        }

        @Override
        protected JobInstanceDao createJobInstanceDao() throws Exception {
                JdbcJobInstanceDao dao = new JdbcJobInstanceDao();
                dao.setJdbcTemplate(jdbcOperations);
                dao.setJobIncrementer(incrementerFactory.getIncrementer(databaseType, tablePrefix + "JOB_SEQ"));
                dao.setTablePrefix(tablePrefix);
                dao.afterPropertiesSet();
                return dao;
        }

        @Override
        protected JobExecutionDao createJobExecutionDao() throws Exception {
                JdbcJobExecutionDao dao = new JdbcJobExecutionDao();
                dao.setJdbcTemplate(jdbcOperations);
                dao.setJobExecutionIncrementer(incrementerFactory.getIncrementer(databaseType, tablePrefix
                                + "JOB_EXECUTION_SEQ"));
                dao.setTablePrefix(tablePrefix);
                dao.setClobTypeToUse(determineClobTypeToUse(this.databaseType));
                dao.setExitMessageLength(maxVarCharLength);
                dao.afterPropertiesSet();
                return dao;
        }

        @Override
        protected StepExecutionDao createStepExecutionDao() throws Exception {
                JdbcStepExecutionDao dao = new JdbcStepExecutionDao();
                dao.setJdbcTemplate(jdbcOperations);
                dao.setStepExecutionIncrementer(incrementerFactory.getIncrementer(databaseType, tablePrefix
                                + "STEP_EXECUTION_SEQ"));
                dao.setTablePrefix(tablePrefix);
                dao.setClobTypeToUse(determineClobTypeToUse(this.databaseType));
                dao.setExitMessageLength(maxVarCharLength);
                dao.afterPropertiesSet();
                return dao;
        }

        @Override
        protected ExecutionContextDao createExecutionContextDao() throws Exception {
                JdbcExecutionContextDao dao = new JdbcExecutionContextDao();
                dao.setJdbcTemplate(jdbcOperations);
                dao.setTablePrefix(tablePrefix);
                dao.setClobTypeToUse(determineClobTypeToUse(this.databaseType));
                dao.setSerializer(serializer);

                if (lobHandler != null) {
                        dao.setLobHandler(lobHandler);
                }

                dao.afterPropertiesSet();
                // Assume the same length.
                dao.setShortContextLength(maxVarCharLength);
                return dao;
        }

        private int determineClobTypeToUse(String databaseType) throws Exception {
                if(lobType != null) {
                        return lobType;
                } else {
                        if (SYBASE == DatabaseType.valueOf(databaseType.toUpperCase())) {
                                return Types.LONGVARCHAR;
                        }
                        else {
                                return Types.CLOB;
                        }
                }
        }

        private boolean isValidTypes(int value) throws Exception {
                boolean result = false;

                for (Field field : Types.class.getFields()) {
                        int curValue = field.getInt(null);
                        if(curValue == value) {
                                result = true;
                                break;
                        }
                }

                return result;
        }

}