#region CPL License
/*
Nuclex.NAnt.Tasks
Copyright (C) 2009 Nuclex Development Labs

This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.

This library 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
IBM Common Public License for more details.

You should have received a copy of the IBM Common Public
License along with this library
*/
#endregion

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

using Microsoft.Win32;

using NAnt.Core;
using NAnt.Core.Attributes;
using NAnt.Core.Types;
using System.Xml;

namespace Nuclex.NAnt.Tasks {

  /// <summary>Removes nodes from XML documents</summary>
  [TaskName("xmlremove")]
  public class XmlRemoveTask : Task {

    /// <summary>Initializes a new XML node removal task</summary>
    public XmlRemoveTask() { }

    /// <summary>XPath of the nodes that will be removed from an XML file</summary>
    [TaskAttribute("xpath", Required = true), StringValidator(AllowEmpty = false)]
    public string XPath {
      get { return this.xPath; }
      set { this.xPath = value; }
    }

    /// <summary>XML file from which nodes will be removed</summary>
    [TaskAttribute("file", Required = true)]
    public FileInfo File {
      get { return this.xmlFile; }
      set { this.xmlFile = value; }
    }

    /// <summary>Executes the task</summary>
    protected override void ExecuteTask() {
      XmlDocument document = new XmlDocument();
      document.Load(this.xmlFile.FullName);

      int count = 0;
      foreach(XmlNode node in document.SelectNodes(this.xPath)) {
        node.ParentNode.RemoveChild(node);
        ++count;
      }

      // If the user wants the task to fail if no nodes matched his XPath, do so now.
      if(count == 0) {
        if(FailOnError) {
          throw new BuildException(String.Format("Node not found by XPath '{0}'", XPath));
        }
      }

      document.Save(this.xmlFile.FullName);

      Log(Level.Info, "Removed {0} XML nodes from {1}", count, this.xmlFile.FullName);
    }

    /// <summary>File to remove nodes from</summary>
    private FileInfo xmlFile;
    /// <summary>XPath for the nodes to be removed</summary>
    private string xPath;

  }

} // namespace Nuclex.NAnt.Tasks