package kr.wisestone.owl.config.persistence.routing;

import com.google.common.collect.Lists;
import kr.wisestone.owl.config.persistence.aop.TransactionDefinitionInterceptor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;

public class TransactionDefinitionRoutingDataSource extends AbstractRoutingDataSource {

    private Logger logger = LoggerFactory.getLogger(this.getClass());

    private List<Object> dataSourceKeys;

    private final AtomicInteger currentIndex = new AtomicInteger();

    @Override
    public void setTargetDataSources(Map<Object, Object> targetDataSources) {
        super.setTargetDataSources(targetDataSources);
        this.dataSourceKeys = Lists.newArrayList(targetDataSources.keySet());
    }

    @Override
    protected Object determineCurrentLookupKey() {
        if (TransactionDefinitionInterceptor
                .isCurrentTransactionReadOnly()
                && !dataSourceKeys.isEmpty()) {
            int size = dataSourceKeys.size();
            Object key = dataSourceKeys.get(currentIndex.getAndIncrement() % size);
            return key;
        }
        return null;
    }

}