package cn.jsxwsl.www.config.datasource;

import cn.jsxwsl.www.nums.DBTypeEnum;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
import org.springframework.lang.Nullable;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;

/**
 * @Author 佚名
 * @Date 2020/3/25 18:26
 */
@Configuration
@EnableTransactionManagement
public class MutiDataSource {

    /**
     * Spring boot提供了AbstractRoutingDataSource
     * 根据用户定义的规则选择当前的数据源，
     * 这样我们可以在执行查询之前，设置使用的数据源。
     * 实现可动态路由的数据源，在每次数据库查询操作前执行。
     * 它的抽象方法 determineCurrentLookupKey() 决定使用哪个数据源。
     */
    static class MyRoutingDataSource extends AbstractRoutingDataSource {
        @Nullable
        @Override
        protected Object determineCurrentLookupKey() {
            // 从当前线程获取到数据源的key
            return DataSourceTheadLocal.get();
        }
    }

    /**
     * 数据源 master
     *
     * @return DataSource
     */
    @Bean
    @ConfigurationProperties("spring.datasource.master")
    public DataSource masterDataSource() {
        return DataSourceBuilder.create().build();
    }

    /**
     * 数据源 slave1
     *
     * @return DataSource
     */
    @Bean
    @ConfigurationProperties("spring.datasource.slave1")
    public DataSource slave1DataSource() {
        return DataSourceBuilder.create().build();
    }

    /**
     * 数据源 slave2
     *
     * @return DataSource
     */
    @Bean
    @ConfigurationProperties("spring.datasource.slave2")
    public DataSource slave2DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    public DataSource myRoutingDataSource(DataSource masterDataSource,
                                          DataSource slave1DataSource,
                                          DataSource slave2DataSource) {
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put(DBTypeEnum.MASTER, masterDataSource);
        targetDataSources.put(DBTypeEnum.SLAVE1, slave1DataSource);
        targetDataSources.put(DBTypeEnum.SLAVE2, slave2DataSource);
        MyRoutingDataSource myRoutingDataSource = new MyRoutingDataSource();
        myRoutingDataSource.setDefaultTargetDataSource(masterDataSource);
        myRoutingDataSource.setTargetDataSources(targetDataSources);
        return myRoutingDataSource;
    }

    /**
     * 配置事务
     *
     * @param myRoutingDataSource DataSource
     * @return PlatformTransactionManager
     */
    @Bean
    public PlatformTransactionManager transactionManager(DataSource myRoutingDataSource) {
        return new DataSourceTransactionManager(myRoutingDataSource);
    }


    /**
     * mybatis
     * @param myRoutingDataSource DataSource
     * @return SqlSessionFactory
     * @throws Exception Exception
     */
    @Bean
    public SqlSessionFactory sqlSessionFactory(DataSource myRoutingDataSource) throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(myRoutingDataSource);
//        sqlSessionFactoryBean.setMapperLocations(
//                new PathMatchingResourcePatternResolver()
//                        .getResources("classpath:mapper/*.xml")
//        );
        return sqlSessionFactoryBean.getObject();
    }


}