/*
 * Copyright (c) 2011-2015 EPFL DATA Laboratory
 * Copyright (c) 2014-2015 The Squall Collaboration (see NOTICE)
 *
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package ch.epfl.data.squall.api.sql.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.schema.Table;

/*
 * This class is necessary because we cannot extract tableSchemaName from column.getTable()
 *   tableSchemaName is the name from TPCH_Schema (non-aliased tableName)
 */
public class TableAliasName {
    private final String _queryName;

    // alias, schemaName
    private final HashMap<String, String> _nameSchemaList = new HashMap<String, String>();

    /*
     * This list of tables is provided from SQLVisitor It won't work if we
     * obtain a list of tables from a list of columns using the method
     * column.getTable()
     */
    public TableAliasName(List<Table> tableList, String queryName) {
	_queryName = queryName;
	for (final Table table : tableList) {
	    final String tableCompName = ParserUtil.getComponentName(table);
	    final String tableSchemaName = table.getWholeTableName();
	    _nameSchemaList.put(tableCompName, tableSchemaName);
	}
    }

    /*
     * Get all component names
     */
    public List<String> getComponentNames() {
	final List<String> result = new ArrayList<String>();
	for (final Iterator iter = _nameSchemaList.entrySet().iterator(); iter
		.hasNext();) {
	    final Map.Entry<String, String> entry = (Map.Entry<String, String>) iter
		    .next();
	    result.add(entry.getKey());
	}
	return result;
    }

    /*
     * Returns "TableSchemaName.ColumnName"
     */
    public String getFullSchemaColumnName(Column column) {
	final String columnName = column.getColumnName();
	final String tableCompName = ParserUtil.getComponentName(column);
	final String tableSchemaName = getSchemaName(tableCompName);
	return tableSchemaName + "." + columnName;
    }

    public String getSchemaName(String tableCompName) {
	final String schemaName = _nameSchemaList.get(tableCompName);
	if (schemaName == null)
	    throw new RuntimeException("Table with alias " + tableCompName
		    + " does not exist in " + _queryName + " query!");
	return schemaName;
    }

}