/**
 * Copyright 2014 Eediom Inc.
 * 
 * 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 org.araqne.logdb.query.expr;

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

import org.araqne.logdb.QueryContext;
import org.araqne.logdb.QueryParseException;
import org.araqne.logdb.Row;

public class Format extends FunctionExpression {
	private String format;
	private List<Expression> argExprs;
	private final int argCount;

	public Format(QueryContext ctx, List<Expression> exprs) {
		super("format", exprs, 2);

		if (!(exprs.get(0) instanceof StringConstant)){
		//	throw new QueryParseException("invalid-format-string", -1);
			Map<String, String> params = new HashMap<String, String>();
			params.put("exp", exprs.get(0).toString());
			throw new QueryParseException("91030", -1, -1, params);
		}

		this.argCount = exprs.size() - 1;
		this.format = exprs.get(0).eval(null).toString();
		this.argExprs = exprs.subList(1, exprs.size());
	}

	@Override
	public Object eval(Row row) {
		try {
			Object[] args = new Object[argExprs.size()];
			int i = 0;
			for (Expression argExpr : argExprs) {
				args[i++] = argExpr.eval(row);
			}

			if (argCount == 1 && args[0] != null) {
				if (args[0] instanceof List) {
					return String.format(format, ((List<?>) args[0]).toArray());
				} else {
					return String.format(format, args[0]);
				}
			} else {
				return String.format(format, args);
			}
		} catch (Throwable t) {
			return null;
		}
	}
}