/*
 * Copyright (c) 1998, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.testing.tests.performance.emulateddb;

import java.sql.*;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.sessions.DatabaseRecord;

/**
 * Emulated database result set meta data.
 * This extracts columns from a list of DatabaseRows.
 */
public class EmulatedResultSetMetaData implements ResultSetMetaData {

    protected EmulatedResultSet resultSet;

    public EmulatedResultSetMetaData(EmulatedResultSet resultSet) {
        this.resultSet = resultSet;
    }

    /**
     * Returns the number of columns in this <code>ResultSet</code> object.
     *
     * @return the number of columns
     * @exception SQLException if a database access error occurs
     */
    @Override
    public int getColumnCount() throws SQLException {
        if (resultSet.getRows().isEmpty()) {
            return 1;
        }
        return ((DatabaseRecord)resultSet.getRows().get(0)).getFields().size();
    }

    /**
     * Indicates whether the designated column is automatically numbered, thus read-only.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    @Override
    public boolean isAutoIncrement(int column) throws SQLException {
        return false;
    }

    /**
     * Indicates whether a column's case matters.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    @Override
    public boolean isCaseSensitive(int column) throws SQLException {
        return true;
    }

    /**
     * Indicates whether the designated column can be used in a where clause.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    @Override
    public boolean isSearchable(int column) throws SQLException {
        return true;
    }

    /**
     * Indicates whether the designated column is a cash value.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    @Override
    public boolean isCurrency(int column) throws SQLException {
        return false;
    }

    /**
     * Indicates the nullability of values in the designated column.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return the nullability status of the given column; one of <code>columnNoNulls</code>,
     *          <code>columnNullable</code> or <code>columnNullableUnknown</code>
     * @exception SQLException if a database access error occurs
     */
    @Override
    public int isNullable(int column) throws SQLException {
        return 0;
    }

    /**
     * Indicates whether values in the designated column are signed numbers.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    @Override
    public boolean isSigned(int column) throws SQLException {
        return true;
    }

    /**
     * Indicates the designated column's normal maximum width in characters.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return the normal maximum number of characters allowed as the width
     *          of the designated column
     * @exception SQLException if a database access error occurs
     */
    @Override
    public int getColumnDisplaySize(int column) throws SQLException {
        return 0;
    }

    /**
     * Gets the designated column's suggested title for use in printouts and
     * displays.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return the suggested column title
     * @exception SQLException if a database access error occurs
     */
    @Override
    public String getColumnLabel(int column) throws SQLException {
        return "";
    }

    /**
     * Get the designated column's name.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return column name
     * @exception SQLException if a database access error occurs
     */
    @Override
    public String getColumnName(int column) throws SQLException {
        return ((DatabaseField)((DatabaseRecord)resultSet.getRows().get(0)).getFields().get(column - 1)).getName();
    }

    /**
     * Get the designated column's table's schema.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return schema name or "" if not applicable
     * @exception SQLException if a database access error occurs
     */
    @Override
    public String getSchemaName(int column) throws SQLException {
        return "";
    }

    /**
     * Get the designated column's number of decimal digits.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return precision
     * @exception SQLException if a database access error occurs
     */
    @Override
    public int getPrecision(int column) throws SQLException {
        return 0;
    }

    /**
     * Gets the designated column's number of digits to right of the decimal point.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return scale
     * @exception SQLException if a database access error occurs
     */
    @Override
    public int getScale(int column) throws SQLException {
        return 0;
    }

    /**
     * Gets the designated column's table name.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return table name or "" if not applicable
     * @exception SQLException if a database access error occurs
     */
    @Override
    public String getTableName(int column) throws SQLException {
        return "";
    }

    /**
     * Gets the designated column's table's catalog name.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return the name of the catalog for the table in which the given column
     *          appears or "" if not applicable
     * @exception SQLException if a database access error occurs
     */
    @Override
    public String getCatalogName(int column) throws SQLException {
        return "";
    }

    /**
     * Retrieves the designated column's SQL type.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return SQL type from java.sql.Types
     * @exception SQLException if a database access error occurs
     * @see Types
     */
    @Override
    public int getColumnType(int column) throws SQLException {
        return 0;
    }

    /**
     * Retrieves the designated column's database-specific type name.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return type name used by the database. If the column type is
     * a user-defined type, then a fully-qualified type name is returned.
     * @exception SQLException if a database access error occurs
     */
    @Override
    public String getColumnTypeName(int column) throws SQLException {
        return "";
    }

    /**
     * Indicates whether the designated column is definitely not writable.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    @Override
    public boolean isReadOnly(int column) throws SQLException {
        return false;
    }

    /**
     * Indicates whether it is possible for a write on the designated column to succeed.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    @Override
    public boolean isWritable(int column) throws SQLException {
        return true;
    }

    /**
     * Indicates whether a write on the designated column will definitely succeed.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return <code>true</code> if so; <code>false</code> otherwise
     * @exception SQLException if a database access error occurs
     */
    @Override
    public boolean isDefinitelyWritable(int column) throws SQLException {
        return true;
    }

    //--------------------------JDBC 2.0-----------------------------------

    /**
     * <p>Returns the fully-qualified name of the Java class whose instances
     * are manufactured if the method <code>ResultSet.getObject</code>
     * is called to retrieve a value
     * from the column.  <code>ResultSet.getObject</code> may return a subclass of the
     * class returned by this method.
     *
     * @param column the first column is 1, the second is 2, ...
     * @return the fully-qualified name of the class in the Java programming
     *         language that would be used by the method
     * <code>ResultSet.getObject</code> to retrieve the value in the specified
     * column. This is the class name used for custom mapping.
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    @Override
    public String getColumnClassName(int column) throws SQLException {
        return "";
    }

    @Override
    public boolean isWrapperFor(Class<?> iFace) throws SQLException{
        return false;
    }

    @Override
    public <T>T unwrap(Class<T> iFace)  throws SQLException {
        return iFace.cast(this);
    }

}