using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Web;
using System.Xml;
using Common.Logging;
using WebDAVSharp.Server.Adapters;
using WebDAVSharp.Server.Exceptions;
using WebDAVSharp.Server.Stores;

namespace WebDAVSharp.Server.MethodHandlers {
	/// <summary>
	/// This class implements the <c>LOCK</c> HTTP method for WebDAV#.
	/// </summary>
	internal class WebDavLockMethodHandler : WebDavMethodHandlerBase, IWebDavMethodHandler {
		/// <summary>
		/// Gets the collection of the names of the HTTP methods handled by this instance.
		/// </summary>
		/// <value>
		/// The names.
		/// </value>
		public IEnumerable<string> Names {
			get {
				return new[]
				{
										"LOCK"
								};
			}
		}

		/// <summary>
		/// Processes the request.
		/// </summary>
		/// <param name="server">The <see cref="WebDavServer" /> through which the request came in from the client.</param>
		/// <param name="context">The
		/// <see cref="IHttpListenerContext" /> object containing both the request and response
		/// objects to use.</param>
		/// <param name="store">The <see cref="IWebDavStore" /> that the <see cref="WebDavServer" /> is hosting.</param>
		/// <exception cref="WebDAVSharp.Server.Exceptions.WebDavPreconditionFailedException"></exception>
		public void ProcessRequest(WebDavServer server, HttpContext context, IWebDavStore store, String fileName) {
			ILog log = LogManager.GetCurrentClassLogger();

			/***************************************************************************************************
			 * Retreive al the information from the request
			 ***************************************************************************************************/

			// read the headers
			int depth = GetDepthHeader(context.Request);
			string timeout = GetTimeoutHeader(context.Request);

			// Initiate the XmlNamespaceManager and the XmlNodes
			XmlNamespaceManager manager = null;
			XmlNode lockscopeNode = null, locktypeNode = null, ownerNode = null;

			// try to read the body
			try {
				StreamReader reader = new StreamReader(context.Request.InputStream, Encoding.UTF8);
				string requestBody = reader.ReadToEnd();

				if (!requestBody.Equals("") && requestBody.Length != 0) {
					XmlDocument requestDocument = new XmlDocument();
					requestDocument.LoadXml(requestBody);

					if (requestDocument.DocumentElement != null && requestDocument.DocumentElement.LocalName != "prop" &&
							requestDocument.DocumentElement.LocalName != "lockinfo") {
						log.Debug("LOCK method without prop or lockinfo element in xml document");
					}

					manager = new XmlNamespaceManager(requestDocument.NameTable);
					manager.AddNamespace("D", "DAV:");
					manager.AddNamespace("Office", "schemas-microsoft-com:office:office");
					manager.AddNamespace("Repl", "http://schemas.microsoft.com/repl/");
					manager.AddNamespace("Z", "urn:schemas-microsoft-com:");

					// Get the lockscope, locktype and owner as XmlNodes from the XML document
					lockscopeNode = requestDocument.DocumentElement.SelectSingleNode("D:lockscope", manager);
					locktypeNode = requestDocument.DocumentElement.SelectSingleNode("D:locktype", manager);
					ownerNode = requestDocument.DocumentElement.SelectSingleNode("D:owner", manager);
				}
				else {
					throw new WebDavPreconditionFailedException();
				}
			}
			catch (Exception ex) {
				log.Warn(ex.Message);
				throw;
			}

			/***************************************************************************************************
			 * Lock the file or folder
			 ***************************************************************************************************/

			bool isNew = false;

			// Get the parent collection of the item
			IWebDavStoreCollection collection = GetParentCollection(server, store, fileName);

			try {
				// Get the item from the collection
				IWebDavStoreItem item = GetItemFromCollection(collection, fileName);
			}
			catch (Exception) {
				collection.CreateDocument(fileName);
				isNew = true;
			}



			/***************************************************************************************************
			 * Create the body for the response
			 ***************************************************************************************************/

			// Create the basic response XmlDocument
			XmlDocument responseDoc = new XmlDocument();
			string responseXml = "<?xml version=\"1.0\" encoding=\"utf-8\" ?><D:prop " +
					"xmlns:D=\"DAV:\"><D:lockdiscovery><D:activelock/></D:lockdiscovery></D:prop>";
			responseDoc.LoadXml(responseXml);

			// Select the activelock XmlNode
			XmlNode activelock = responseDoc.DocumentElement.SelectSingleNode("D:lockdiscovery/D:activelock", manager);

			// Import the given nodes
			activelock.AppendChild(responseDoc.ImportNode(lockscopeNode, true));
			activelock.AppendChild(responseDoc.ImportNode(locktypeNode, true));
			activelock.AppendChild(responseDoc.ImportNode(ownerNode, true));

			// Add the additional elements, e.g. the header elements

			// The timeout element
			WebDavProperty timeoutProperty = new WebDavProperty("timeout", timeout);
			activelock.AppendChild(timeoutProperty.ToXmlElement(responseDoc));

			// The depth element
			WebDavProperty depthProperty = new WebDavProperty("depth", (depth == 0 ? "0" : "Infinity"));
			activelock.AppendChild(depthProperty.ToXmlElement(responseDoc));

			// The locktoken element
			WebDavProperty locktokenProperty = new WebDavProperty("locktoken", "");
			XmlElement locktokenElement = locktokenProperty.ToXmlElement(responseDoc);
			WebDavProperty hrefProperty = new WebDavProperty("href", "opaquelocktoken:e71d4fae-5dec-22df-fea5-00a0c93bd5eb1");
			locktokenElement.AppendChild(hrefProperty.ToXmlElement(responseDoc));
			activelock.AppendChild(locktokenElement);

			/***************************************************************************************************
			 * Send the response
			 ***************************************************************************************************/

			// convert the StringBuilder
			string resp = responseDoc.InnerXml;
			byte[] responseBytes = Encoding.UTF8.GetBytes(resp);

			if (isNew) {
				// HttpStatusCode doesn't contain WebDav status codes, but HttpWorkerRequest can handle these WebDav status codes
				context.Response.StatusCode = (int)HttpStatusCode.Created;
				context.Response.StatusDescription = HttpWorkerRequest.GetStatusDescription((int)HttpStatusCode.Created);
			}
			else {
				// HttpStatusCode doesn't contain WebDav status codes, but HttpWorkerRequest can handle these WebDav status codes
				context.Response.StatusCode = (int)HttpStatusCode.OK;
				context.Response.StatusDescription = HttpWorkerRequest.GetStatusDescription((int)HttpStatusCode.OK);
			}


			// set the headers of the response
			//context.Response.ContentLength64 = responseBytes.Length;
			//context.Response.AdaptedInstance.ContentType = "text/xml";
			context.Response.ContentType = "text/xml";


			// the body
			context.Response.OutputStream.Write(responseBytes, 0, responseBytes.Length);

			//context.Response.Close();
		}
	}
}