package de.superx.spring.batch.reader;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

import org.h2.jdbcx.JdbcDataSource;
import org.junit.Assert;
import org.junit.Test;

import de.superx.job.ExtractAction;

public class JdbcExtractReaderTest {

    /**
     * Dieser Test soll sicher stellen, dass der "JdbcExtractReader" einen Schemafilter als Parameter übergibt;
     * dies ist notwendig, weil er Metadaten über Datenbanktabellen ausliest, um für einzelne Tabellen SQL-Statements
     * zu erzeugen - ohne die Filterung nach Schemata besteht die Gefahr, dass Metadaten unterschiedlicher Tabellen
     * gleichen Namens vermischt werden
     * @throws SQLException
     */
    @SuppressWarnings("static-method")
    @Test
    public void testSchemaConsideration() throws SQLException {
        ExtractAction ea = createExtractAction();
        JdbcDataSource dataSource = initializeH2Datasource();
        try (Connection con = dataSource.getConnection(); Statement st = con.createStatement()) {
            JdbcExtractReader<Integer> extrR = new JdbcExtractReader<Integer>(ea, dataSource);
            extrR.beforeStep(null);
            String generated_sql = extrR.selectFromTableStmt;
            Assert.assertTrue("generated SQL should not contain 'should_not_appear' when schema filtering works", !generated_sql.contains("should_not_appear"));
        } catch (SQLException sqle) {
            throw sqle;
        }
    }

    private static JdbcDataSource initializeH2Datasource() throws SQLException {
        String h2Url = "jdbc:h2:mem:schema_test;DB_CLOSE_DELAY=-1;INIT=CREATE SCHEMA extract_schema;MODE=POSTGRESQL;DATABASE_TO_LOWER=TRUE";
        JdbcDataSource dataSource = new JdbcDataSource();
        dataSource.setURL(h2Url);
        dataSource.setUser("sa");
        dataSource.setPassword("");
        try (Connection con = dataSource.getConnection(); Statement st = con.createStatement()) {
            st.execute("CREATE TABLE extract_schema.extract_table(id INT, name TEXT);");
            st.execute("CREATE SCHEMA a_schema2;");
            st.execute("CREATE TABLE a_schema2.extract_table(should_not_appear TEXT);");
        }
        h2Url = "jdbc:h2:mem:schema_test;DB_CLOSE_DELAY=-1;SCHEMA=extract_schema;MODE=POSTGRESQL;DATABASE_TO_LOWER=TRUE";
        dataSource.setURL(h2Url);
        return dataSource;
    }

    private static ExtractAction createExtractAction() {
        ExtractAction ea = new ExtractAction();
        ea.sourceTable = "extract_table";
        ea.stagingSchema = "staging_schema";
        ea.stagingTable = "staging_table";
        ea.extractionScript = "1=1 -- extraction_script";
        ea.dataSource = "dummy";
        return ea;
    }
}