// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Configuration.Internal;
using System.IO;
using System.Xml;
 
namespace System.Configuration
{
    // ConfigXmlDocument - the default Xml Document doesn't track line numbers, and line
    // numbers are necessary to display source on config errors.
    // These classes wrap corresponding System.Xml types and also carry
    // the necessary information for reporting filename / line numbers.
    // Note: these classes will go away if webdata ever decides to incorporate line numbers
    // into the default XML classes.  This class could also go away if webdata brings back
    // the UserData property to attach any info off of any node.
    public sealed class ConfigXmlDocument : XmlDocument, IConfigErrorInfo
    {
        private XmlTextReader _reader;
        private int _lineOffset;
        private string _filename;
 
        int IConfigErrorInfo.LineNumber
        {
            get
            {
                if (_reader == null)
                {
                    return 0;
                }
 
                if (_lineOffset > 0)
                {
                    return _reader.LineNumber + _lineOffset - 1;
                }
 
                return _reader.LineNumber;
            }
        }
 
        public int LineNumber { get { return ((IConfigErrorInfo)this).LineNumber; } }
 
        public string Filename
        {
            get { return _filename; }
        }
 
        string IConfigErrorInfo.Filename
        {
            get { return _filename; }
        }
 
        public override void Load(string filename)
        {
            _filename = filename;
            try
            {
                _reader = new XmlTextReader(filename);
                _reader.XmlResolver = null;
                base.Load(_reader);
            }
            finally
            {
                if (_reader != null)
                {
                    _reader.Close();
                    _reader = null;
                }
            }
        }
 
        public void LoadSingleElement(string filename, XmlTextReader sourceReader)
        {
            _filename = filename;
            _lineOffset = sourceReader.LineNumber;
            string outerXml = sourceReader.ReadOuterXml();
 
            try
            {
                _reader = new XmlTextReader(new StringReader(outerXml), sourceReader.NameTable);
                base.Load(_reader);
            }
            finally
            {
                if (_reader != null)
                {
                    _reader.Close();
                    _reader = null;
                }
            }
        }
 
        public override XmlAttribute CreateAttribute(string prefix, string localName, string namespaceUri)
        {
            return new ConfigXmlAttribute(_filename, LineNumber, prefix, localName, namespaceUri, this);
        }
 
        public override XmlElement CreateElement(string prefix, string localName, string namespaceUri)
        {
            return new ConfigXmlElement(_filename, LineNumber, prefix, localName, namespaceUri, this);
        }
 
        public override XmlText CreateTextNode(string text)
        {
            return new ConfigXmlText(_filename, LineNumber, text, this);
        }
 
        public override XmlCDataSection CreateCDataSection(string data)
        {
            return new ConfigXmlCDataSection(_filename, LineNumber, data, this);
        }
 
        public override XmlComment CreateComment(string data)
        {
            return new ConfigXmlComment(_filename, LineNumber, data, this);
        }
 
        public override XmlSignificantWhitespace CreateSignificantWhitespace(string data)
        {
            return new ConfigXmlSignificantWhitespace(_filename, LineNumber, data, this);
        }
 
        public override XmlWhitespace CreateWhitespace(string data)
        {
            return new ConfigXmlWhitespace(_filename, LineNumber, data, this);
        }
    }
}