// code from: http://www.heikniemi.net/hc/archives/000205.html
//       and: http://www.heikniemi.net/hc/archives/files/Upload.cs

using System;
using System.Collections;
using System.Collections.Specialized;
using System.IO;
using System.Net;

namespace eBay_Images {
	/// <summary>
	/// Provides functionality for programmatically uploading files 
	/// with the HTTP protocol.
	/// </summary>
	public sealed class HttpUpload {
		#region Constructor

		/// <summary>
		/// Private Constructor (prevents the object from being built)
		/// </summary>
		private HttpUpload() { }

		#endregion

		#region UploadFile

		/// <summary>
		/// Uploads the given file to the given url.
		/// </summary>
		/// <param name="pathname">The pathname of the file to be uploaded.</param>
		/// <param name="uri">The URI to which the file shall be sent.</param>
		/// <param name="fieldName">The name of the form field for the upload.</param>
		/// <param name="cookies">Cookies to be sent with the request.</param>
		/// <param name="credentials">Login credentials to be passed.</param>
		public static HttpWebResponse UploadFile(string pathname, Uri uri, string fieldName,
												 CookieContainer cookies, ICredentials credentials) {

			return Upload(uri, cookies, credentials, new UploadSpec(pathname, fieldName));
		}

		#endregion

		#region UploadByteArray

		/// <summary>
		/// Uploads the given byte array to the given url.
		/// </summary>
		/// <param name="data">The data to be uploaded.</param>
		/// <param name="fileName">The name to be sent as the filename.</param>
		/// <param name="uri">The URI to which the file shall be sent.</param>
		/// <param name="fieldName">The name of the form field for the upload.</param>
		/// <param name="cookies">Cookies to be sent with the request.</param>
		/// <param name="credentials">Login credentials to be passed.</param>
		public static HttpWebResponse UploadByteArray(byte[] data, string fileName, Uri uri, string fieldName,
													  CookieContainer cookies, ICredentials credentials) {

			return Upload(uri, cookies, credentials, new UploadSpec(data, fileName, fieldName));
		}

		#endregion

		#region Upload

		/// <summary>
		/// Uploads the given data.
		/// </summary>
		/// <param name="uri">The URI to which the data shall be sent.</param>
		/// <param name="cookies">Cookies to be sent with the request.</param>
		/// <param name="credentials">Login credentials to be passed.</param>
		/// <param name="objects">The data to be sent.</param>
		public static HttpWebResponse Upload(Uri uri, CookieContainer cookies, ICredentials credentials, params UploadSpec[] objects) {
			return Upload(uri, null, cookies, credentials, objects);
		}

		/// <summary>
		/// Uploads the given data.
		/// </summary>
		/// <param name="uri">The URI to which the data shall be sent.</param>
		/// <param name="formFields">Form fields to be posted along with the file.</param>
		/// <param name="cookies">Cookies to be sent with the request.</param>
		/// <param name="credentials">Login credentials to be passed.</param>
		/// <param name="objects">The data to be sent.</param>
		public static HttpWebResponse Upload(Uri uri, StringDictionary formFields, CookieContainer cookies, ICredentials credentials, params UploadSpec[] objects) {
			// Initialize the request object
			HttpWebRequest req = (WebRequest.Create(uri) as HttpWebRequest);
			if (cookies != null) req.CookieContainer = cookies;
			if (credentials != null) req.Credentials = credentials;

			string boundary = Guid.NewGuid().ToString("N");
			req.ContentType = "multipart/form-data; boundary=" + boundary;
			req.Method = "POST";

			MemoryStream postData = new MemoryStream();
			string newLine = "\r\n";
			StreamWriter sw = new StreamWriter(postData);

			if (formFields != null)
				foreach (DictionaryEntry de in formFields) {
					sw.Write("--" + boundary + newLine);
					sw.Write("Content-Disposition: form-data; name=\"{0}\"{1}{1}{2}{1}",
						de.Key,
						newLine,
						de.Value);
				}

			foreach (UploadSpec us in objects) {
				sw.Write("--" + boundary + newLine);
				sw.Write("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"{2}",
					us.FieldName,
					us.FileName,
					newLine);
				sw.Write("Content-Type: application/octet-stream" + newLine + newLine);
				sw.Flush();

				postData.Write(us.Contents, 0, us.Contents.Length);
				sw.Write(newLine);
			}

			sw.Write("--{0}--{1}", boundary, newLine);
			sw.Flush();

			req.ContentLength = postData.Length;
			using (Stream s = req.GetRequestStream())
				postData.WriteTo(s);
			postData.Close();

			return (req.GetResponse() as HttpWebResponse);
		}

		#endregion
	}

	/// <summary>
	/// Holds the information about the file(s) to be uploaded.
	/// </summary>
	public struct UploadSpec {
		#region Member Variables

		private byte[] contents;
		private string fileName;
		private string fieldName;

		#endregion

		#region Properties

		/// <summary>
		/// The byte array content to be uploaded.
		/// </summary>
		public byte[] Contents {
			get { return contents; }
			set { contents = value; }
		}

		/// <summary>
		/// The name of the file to be uploaded.
		/// </summary>
		public string FileName {
			get { return fileName; }
			set { fileName = value; }
		}

		/// <summary>
		/// The HTML form field the file should be uploaded into.
		/// </summary>
		public string FieldName {
			get { return fieldName; }
			set { fieldName = value; }
		}

		#endregion

		#region UploadSpec

		/// <summary>
		/// Creates a new upload spec based on a byte array.
		/// </summary>
		/// <param name="contents">The contents to be uploaded.</param>
		/// <param name="fileName">The file to be uploaded.</param>
		/// <param name="fieldName">The field name as which this file shall be sent to.</param>
		public UploadSpec(byte[] contents, string fileName, string fieldName) {
			this.contents = contents;
			this.fileName = fileName;
			this.fieldName = fieldName;
		}

		/// <summary>
		/// Creates a new upload spec based on a file name.
		/// </summary>
		/// <param name="pathname"></param>
		/// <param name="fieldName"></param>
		public UploadSpec(string pathname, string fieldName) {
			using (FileStream inFile = new FileStream(pathname, FileMode.Open)) {
				byte[] inBytes = new byte[inFile.Length];
				inFile.Read(inBytes, 0, inBytes.Length);
				this.contents = inBytes;
			}
			this.fileName = Path.GetFileName(pathname);
			this.fieldName = fieldName;
		}

		#endregion
	}
}