/*
 * ParserLogException.cs
 *
 * This work is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License,
 * or (at your option) any later version.
 *
 * This work is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 * As a special exception, the copyright holders of this library give
 * you permission to link this library with independent modules to
 * produce an executable, regardless of the license terms of these
 * independent modules, and to copy and distribute the resulting
 * executable under terms of your choice, provided that you also meet,
 * for each linked independent module, the terms and conditions of the
 * license of that module. An independent module is a module which is
 * not derived from or based on this library. If you modify this
 * library, you may extend this exception to your version of the
 * library, but you are not obligated to do so. If you do not wish to
 * do so, delete this exception statement from your version.
 *
 * Copyright (c) 2003 Per Cederberg. All rights reserved.
 */

using System;
using System.Collections;
using System.Text;

namespace PerCederberg.Grammatica.Parser {

    /**
     * A parser log exception. This class contains a list of all the parse
     * errors encountered while parsing.
     *
     * @author   Per Cederberg, <per at percederberg dot net>
     * @version  1.1
     * @since    1.1
     */
    public class ParserLogException : Exception {
    
        /**
         * The list of errors found.
         */
        private ArrayList errors = new ArrayList();
    
        /**
         * Creates a new empty parser log exception.
         */
        public ParserLogException() {
        }
    
        /**
         * The message property. This property contains the detailed
         * exception error message.
         */
        public override string Message {
            get{
                return GetMessage(); 
            }   
        }

        /**
         * Returns the number of errors in this log.
         * 
         * @return the number of errors in this log
         */
        public int GetErrorCount() {
            return errors.Count;    
        }
        
        /**
         * Returns a specific error from the log.
         * 
         * @param index          the error index, 0 <= index < count
         * 
         * @return the parse error requested
         */
        public ParseException GetError(int index) {
            return (ParseException) errors[index];
        }
    
        /**
         * Adds a parse error to the log.
         * 
         * @param e              the parse error to add
         */    
        public void AddError(ParseException e) {
            errors.Add(e);
        }
        
        /**
         * Returns the detailed error message. This message will contain
         * the error messages from all errors in this log, separated by
         * a newline.
         * 
         * @return the detailed error message
         */
        public string GetMessage() {
            StringBuilder  buffer = new StringBuilder();
            
            for (int i = 0; i < GetErrorCount(); i++) {
                if (i > 0) {
                    buffer.Append("\n");
                }
                buffer.Append(GetError(i).GetMessage());
            }
            return buffer.ToString();
        }    
    }
}