using System;
using System.IO;
using System.Text;
using System.Web;
using System.Web.SessionState;

namespace CodeBackpack.Test.Http
{
    /// <summary>
    /// The <see cref="IHttpHandler"/> unit test utility.
    /// </summary>
    public class HttpHandlerTest
    {
        private readonly StringWriter output = new StringWriter();
        private readonly HttpContext context;

        protected HttpHandlerTest(string requestMethod, string requestBody, Encoding requestEncoding, string page, string query)
        {
            WorkerRequestStub workerRequest = new WorkerRequestStub(requestMethod,
                requestBody, requestEncoding, page, query, output);
            context = new HttpContext(workerRequest);
            if (requestMethod == "POST")
            {
                context.Request.ContentEncoding = requestEncoding;
            }
            
            // If the handler under test happens to need the session state, here you go:
            SessionIDManager idManager = new SessionIDManager();
            SessionStateUtility.AddHttpSessionStateToContext(context,
                new HttpSessionStateContainer(
                    idManager.CreateSessionID(context),
                    new SessionStateItemCollection(),
                    new HttpStaticObjectsCollection(),
                    60,
                    true,
                    HttpCookieMode.UseCookies,
                    SessionStateMode.InProc,
                    true));
        }

        /// <summary>
        /// Pretend a GET request was issued.
        /// </summary>
        /// <param name="virtualPath">The path part of URL. Don't give a URL like
        /// <code>http://foo/myhandler.ashx</code>, instead supply just <code>myhandler.ashx</code>
        /// </param>
        public static HttpHandlerTest ImitateGet(String virtualPath)
        {
            HttpHandlerTest httpHandlerTest = new HttpHandlerTest("GET", null, null, virtualPath, null);
            return httpHandlerTest;
        }

        /// <summary>
        /// Pretend a POST request was issued.
        /// </summary>
        /// <param name="virtualPath">See above.</param>
        /// <param name="requestBody">The POST request content.</param>
        /// <param name="requestEncoding">The POST request encoding that the handler is supposed to expect.</param>
        public static HttpHandlerTest ImitatePost(String virtualPath, String requestBody, Encoding requestEncoding)
        {
            HttpHandlerTest httpHandlerTest = new HttpHandlerTest("POST", requestBody, requestEncoding, virtualPath, null);
            return httpHandlerTest;
        }

        public virtual void Execute(IHttpHandler testSubject)
        {
            testSubject.ProcessRequest(context);
            // Force the data accumulated in internal response buffers to be written
            // to 'output' StringWriter.
            context.Response.Flush();
        }

        public virtual String Output
        {
            get { return output.ToString(); }
        }

        public virtual HttpContext Context
        {
            get { return context; }
        }
    }
}