package com.ruoyi.shadow.config;

import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.TransactionDefinition;

import javax.sql.DataSource;
import java.sql.Connection;

/**
 * Rejects write-capable transaction definitions without emitting the
 * unsupported SQL Server statement {@code SET TRANSACTION READ ONLY}.
 * Database permissions remain the authoritative write barrier.
 */
final class SqlServerReadOnlyTransactionManager
        extends DataSourceTransactionManager {
    SqlServerReadOnlyTransactionManager(DataSource dataSource) {
        super(dataSource);
        setEnforceReadOnly(true);
    }

    @Override
    protected void doBegin(Object transaction,
                           TransactionDefinition definition) {
        if (!definition.isReadOnly()) {
            throw new IllegalStateException(
                    "SHADOW_SOURCE_TRANSACTION_MUST_BE_READ_ONLY");
        }
        super.doBegin(transaction, definition);
    }

    @Override
    protected void prepareTransactionalConnection(
            Connection connection, TransactionDefinition definition) {
        // SQL Server JDBC treats Connection#setReadOnly as a hint and SQL
        // Server does not support SET TRANSACTION READ ONLY. The source login
        // is independently verified to have no production write permission.
    }
}