// NAnt - A .NET build tool
// Copyright (C) 2001 Gerry Shaw
//
// This program 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 program 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
//
// Ian MacLean (imaclean@gmail.com)
// Gerry Shaw (gerry_shaw@yahoo.com)

using System;
using System.Globalization;
using System.IO;
using System.Text;

namespace NAnt.Core {

    /// <summary>
    /// Stores the file name, line number and column number to record a position 
    /// in a text file.
    /// </summary>
    [Serializable]
    public class Location {
        #region Private Instance Fields

        private string _fileName;
        private int _lineNumber;
        private int _columnNumber;

        #endregion Private Instance Fields

        public static readonly Location UnknownLocation = new Location();

        /// <summary>
        /// Creates a location consisting of a file name, line number and 
        /// column number.
        /// </summary>
        /// <remarks>
        /// <paramref name="fileName" /> can be a local URI resource, e.g., file:///C:/WINDOWS/setuplog.txt.
        /// </remarks>
        public Location(string fileName, int lineNumber, int columnNumber) {
            Init(fileName, lineNumber, columnNumber);
        }

        /// <summary>
        /// Creates a location consisting of a file name.
        /// </summary>
        /// <remarks>
        /// <paramref name="fileName" /> can be a local URI resource, e.g., file:///C:/WINDOWS/setuplog.txt.
        /// </remarks>
        public Location(string fileName) {
            Init(fileName, 0, 0);
        }

        /// <summary>
        /// Creates an "unknown" location.
        /// </summary>
        private Location() {
            Init(null, 0, 0);
        }

        /// <summary>Private Init function.</summary>
        private void Init(string fileName, int lineNumber, int columnNumber) {
            if (fileName != null) {
                try {
                    // first check to see if fileName is a URI
                    Uri uri = new Uri(fileName);
                    fileName = uri.LocalPath;
                } catch {
                    try {
                        // must be a simple filename
                        fileName = Path.GetFullPath(fileName);
                    } catch (ArgumentException) {
                        // when filename is an invalid path, just leave it as 
                        // is
                    }
                }
            }
            _fileName = fileName;
            _lineNumber = lineNumber;
            _columnNumber = columnNumber;
        }

        /// <summary>
        /// Gets a string containing the file name for the location.
        /// </summary>
        /// <remarks>
        /// The file name includes both the file path and the extension.
        /// </remarks>
        public string FileName {
            get { return _fileName; }
        }

        /// <summary>
        /// Gets the line number for the location.
        /// </summary>
        /// <remarks>
        /// Lines start at 1.  Will be zero if not specified.
        /// </remarks>
        public int LineNumber {
            get { return _lineNumber; }
        }

        /// <summary>
        /// Gets the column number for the location.
        /// </summary>
        /// <remarks>
        /// Columns start a 1.  Will be zero if not specified.
        /// </remarks>
        public int ColumnNumber {
            get { return _columnNumber; }
        }

        /// <summary>
        /// Returns the file name, line number and a trailing space. An error
        /// message can be appended easily. For unknown locations, returns
        /// an empty string.
        ///</summary>
        public override string ToString() {
            StringBuilder sb = new StringBuilder("");

            if (_fileName != null) {
                sb.Append(_fileName);
                if (_lineNumber != 0) {
                    sb.Append(String.Format(CultureInfo.InvariantCulture, "({0},{1})", _lineNumber, _columnNumber));
                }
                sb.Append(":");
            }

            return sb.ToString();
        }
    }
}