using System.Collections.Generic;
using System.Net;
using Mtp2Dav.WebDAVSharp.Server._1d2086a502937936ebc6bfe19cfa15d855be1c31.Adapters;
using Mtp2Dav.WebDAVSharp.Server._1d2086a502937936ebc6bfe19cfa15d855be1c31.Exceptions;
using Mtp2Dav.WebDAVSharp.Server._1d2086a502937936ebc6bfe19cfa15d855be1c31.Stores;

namespace Mtp2Dav.WebDAVSharp.Server._1d2086a502937936ebc6bfe19cfa15d855be1c31.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 => 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="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, IHttpListenerContext context, IWebDavStore store)
        {
            var collection = GetParentCollection(server, store, context.Request.Url);
            var item = GetItemFromCollection(collection, context.Request.Url);
            var doc = item as IWebDavStoreDocument;
            if (doc == null)
                throw new WebDavNotFoundException();

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

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

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

                var 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();
        }
    }
}