using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;
using log4net;

namespace Pithos.Network
{
    public static class WebExtensions
    {

        public static string ReadToEnd(this HttpWebResponse response)
        {
            using (var stream = response.GetResponseStream())
            {
                if (stream == null)
                    return null;
                using (var reader = new StreamReader(stream))
                {
                    var body = reader.ReadToEnd();
                    return body;
                }
            }
        }
    
        public static void LogError(this ILog log,HttpWebResponse response)
        {
            if (log.IsDebugEnabled)
            {
                if (response != null)
                {
                    var body = response.ReadToEnd();
                    log.ErrorFormat("Headers:\n{0}\nBody:{1}", response.Headers,body);
                }
            }
        }

        public static TextReader GetLoggedReader(this Stream stream, ILog log)
        {
            var reader = new StreamReader(stream);
            if (!log.IsDebugEnabled)
                return reader;
            
            using (reader)
            {
                var body = reader.ReadToEnd();
                log.DebugFormat("JSON response: {0}", body);
                return new StringReader(body);
            }
        }


        public static TOut NullSafe<TIn, TOut>(this TIn obj, Func<TIn, TOut> memberAction)
        {
            //Note we should not use obj != null because it can not test value types and also
            //compiler has to lift the type to a nullable type for doing the comparision with null.
            return (!EqualityComparer<TIn>.Default.Equals(obj, default(TIn))) ? memberAction(obj) : default(TOut);

        }




    }
}