using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Web;
using WebDAVSharp.Server.Adapters;
using WebDAVSharp.Server.Exceptions;
using WebDAVSharp.Server.Stores;

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

		/// <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.WebDavNotFoundException"></exception>
		/// <exception cref="WebDavNotFoundException"><para>
		///   <paramref name="context" /> specifies a request for a store item that does not exist.</para>
		/// <para>- or -</para>
		/// <para>
		///   <paramref name="context" /> specifies a request for a store item that is not a document.</para></exception>
		/// <exception cref="WebDavConflictException"><paramref name="context" /> specifies a request for a store item using a collection path that does not exist.</exception>
		public void ProcessRequest(WebDavServer server, HttpContext context, IWebDavStore store, String fileName) {
			IWebDavStoreCollection collection = GetParentCollection(server, store, fileName);
			IWebDavStoreItem item = GetItemFromCollection(collection, fileName);
			IWebDavStoreDocument doc = item as IWebDavStoreDocument;
			if (doc == null)
				throw new WebDavNotFoundException();

			long docSize = doc.Size;
			if (docSize == 0) {
				context.Response.StatusCode = (int)HttpStatusCode.OK;
				//context.Response.ContentLength64 = 0;
			}

			using (Stream stream = doc.OpenReadStream()) {
				context.Response.StatusCode = (int)HttpStatusCode.OK;

				//if (docSize > 0)
				//    context.Response.ContentLength64 = docSize;

				byte[] buffer = new byte[4096];
				int inBuffer;
				while ((inBuffer = stream.Read(buffer, 0, buffer.Length)) > 0)
					context.Response.OutputStream.Write(buffer, 0, inBuffer);
			}
			//context.Response.Close();
		}
	}
}