// WFS provider by Peter Robineau (peter.robineau@gmx.at)

// This file can be redistributed and/or modified under the terms of the GNU Lesser General Public License.

using System;

using System.Collections.Specialized;

using System.Diagnostics;

using System.IO;

using System.Net;

using System.Security;

namespace SharpMap.Utilities.Wfs

{

/// <summary>

/// This class provides an easy to use interface for HTTP-GET and HTTP-POST requests.

/// </summary>

public class HttpClientUtil

{

#region Fields and Properties

private readonly NameValueCollection _requestHeaders;

private byte[] _postData;

private string _proxyUrl;

private string _url;

private HttpWebRequest _webRequest;

private HttpWebResponse _webResponse;

/// <summary>

/// Gets ans sets the Url of the request.

/// </summary>

public string Url

{

get { return _url; }

set { _url = value; }

}

/// <summary>

/// Gets and sets the proxy Url of the request.

/// </summary>

public string ProxyUrl

{

get { return _proxyUrl; }

set { _proxyUrl = value; }

}

/// <summary>

/// Sets the data of a HTTP POST request as byte array.

/// </summary>

public byte[] PostData

{

set { _postData = value; }

}

/// <summary>

/// Gets or sets the network credentials used for authenticating the request with the Internet resource

/// </summary>

public ICredentials Credentials { get; set; }

#endregion

#region Constructors

/// <summary>

/// Initializes a new instance of the <see cref="HttpClientUtil"/> class.

/// </summary>

public HttpClientUtil()

{

_requestHeaders = new NameValueCollection();

}

#endregion

#region Public Member

/// <summary>

/// Adds a HTTP header.

/// </summary>

/// <param name="name">The name of the header</param>

/// <param name="value">The value of the header</param>

public void AddHeader(string name, string value)

{

_requestHeaders.Add(name, value);

}

/// <summary>

/// Performs a HTTP-GET or HTTP-POST request and returns a datastream for reading.

/// </summary>

public Stream GetDataStream()

{

if (string.IsNullOrEmpty(_url))

throw new ArgumentNullException("Request Url is not set!");

// Free all resources of the previous request, if it hasn't been done yet...

Close();

try

{

_webRequest = (HttpWebRequest) WebRequest.Create(_url);

}

catch (SecurityException ex)

{

Trace.TraceError("An exception occured due to security reasons while initializing a request to " + _url +

": " + ex.Message);

throw ex;

}

catch (NotSupportedException ex)

{

Trace.TraceError("An exception occured while initializing a request to " + _url + ": " + ex.Message);

throw ex;

}

_webRequest.Timeout = 90000;

if (!string.IsNullOrEmpty(_proxyUrl))

_webRequest.Proxy = new WebProxy(_proxyUrl);

try

{

_webRequest.Headers.Add(_requestHeaders);

if (Credentials != null)

{

_webRequest.UseDefaultCredentials = false;

_webRequest.Credentials = Credentials;

}

/* HTTP POST */

if (_postData != null)

{

_webRequest.ContentLength = _postData.Length;

_webRequest.Method = WebRequestMethods.Http.Post;

using (Stream requestStream = _webRequest.GetRequestStream())

{

requestStream.Write(_postData, 0, _postData.Length);

}

}

/* HTTP GET */

else

_webRequest.Method = WebRequestMethods.Http.Get;

_webResponse = (HttpWebResponse) _webRequest.GetResponse();

return _webResponse.GetResponseStream();

}

catch (Exception ex)

{

Trace.TraceError("An exception occured during a HTTP request to " + _url + ": " + ex.Message);

throw ex;

}

}

/// <summary>

/// This method resets all configurations.

/// </summary>

public void Reset()

{

_url = null;

_proxyUrl = null;

_postData = null;

_requestHeaders.Clear();

}

/// <summary>

/// This method closes the WebResponse object.

/// </summary>

public void Close()

{

if (_webResponse != null)

{

/*

* The Close method closes the response stream and releases the connection

* to the resource for reuse by other requests.

*

* You must call either the Stream.Close or the HttpWebResponse.Close

* method to close the stream and release the connection for reuse.

* It is not necessary to call both Stream.Close and HttpWebResponse.Close,

* but doing so does not cause an error. Failure to close the stream

* can cause your application to run out of connections.

*/

_webResponse.Close();

//_webResponse.GetResponseStream().Dispose();

}

}

#endregion

}

}