////////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  Note:
//
using System;
using System.Runtime.CompilerServices;
using System.Threading;

using Microsoft.Singularity;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.V1.Services;
using Microsoft.Singularity.Io;
using Microsoft.Singularity.Channels;

using Microsoft.Singularity.Channels;
using Microsoft.Contracts;
using Microsoft.SingSharp.Reflection;
using Microsoft.Singularity.Applications;
using Microsoft.Singularity.Io;
using Microsoft.Singularity.Configuration;
[assembly: Transform(typeof(ApplicationResourceTransform))]

namespace Microsoft.Singularity.Applications 
{
    [ConsoleCategory(HelpMessage="Raw disk read performance test", DefaultAction=true)]
    internal class Parameters 
    {
        [InputEndpoint("data")]
        public readonly TRef<UnicodePipeContract.Exp:READY> Stdin;

        [OutputEndpoint("data")]
        public readonly TRef<UnicodePipeContract.Imp:READY> Stdout;

        [Endpoint]
        public readonly TRef<DirectoryServiceContract.Imp:Start> nsRef;

        [StringParameter( "device", Mandatory=true, Position=0 , HelpMessage="Raw device to read")]
        internal string deviceName;

        [LongParameter( "mb", Default=10, HelpMessage="Megabytes to read.")]
        internal long numMB;

        [LongParameter( "chunk", Default=65536, HelpMessage="Chunk size for each read.")]
        internal long chunkSize;

        [LongParameter( "r", Default=1, HelpMessage="Repetition count.")]
        internal long repetitions;

        reflective internal Parameters();

        internal int AppMain() {
            return DiskRead.AppMain(this);
        }
    }

    public class DiskRead
    {
        public static DiskDeviceContract.Imp:Ready OpenDevice(String! devname)
        {
            DiskDeviceContract.Exp! exp;
            DiskDeviceContract.Imp! imp;
            DiskDeviceContract.NewChannel(out imp, out exp);
            DirectoryServiceContract.Imp ns;

            // get NS endpoint
            ns = DirectoryService.NewClientEndpoint();
            bool success = false;
            ErrorCode error; 
            success = SdsUtils.Bind(devname, ns, exp, out error);
            if (!success) {
                Console.WriteLine("Bind of {0} failed\n", devname);
                delete imp;
                delete ns;
                return null;
            }
            switch receive {
                case imp.Success():
                    break;
                case imp.ContractNotSupported():
                    Console.WriteLine("{0} does not support DiskDevice", devname);
                    delete imp;
                    delete ns;
                    return null;
                case imp.ChannelClosed():
                    Console.WriteLine("DiskDevice channel to {0} closed unexpectedly", devname);
                    delete imp;
                    delete ns;
                    return null;
            }

            delete ns;
            return imp;
        }

        public static bool StringToNumber(String! s, out ulong num)
        {
            char [] arr;

            if (s.Length == 0) {
                num = 0;
                return false;
            }

            arr = s.ToCharArray();
            foreach (char c in arr) {
                if (!Char.IsDigit(c)) {
                    num = 0;
                    return false;
                }
            }
            num = (ulong) int.Parse(s);
            return true;
        }


        private static void  DisplayPerf(long ticks, long cycles, ulong numMB, ulong chunkSize)
        {
            double elapsed   = ticks / 10000000.0;
            double opsPerSec = numMB * 1024 * 1024 / (elapsed * chunkSize);
            double mbPerSec  = numMB / elapsed;
            Console.WriteLine("Ops/s: {0:f2}  MB/s: {1:f2}  Elapsed: {2:f2}",
                              opsPerSec, mbPerSec, elapsed);
        }

        internal static int AppMain(Parameters! config)
        {
            long numMB = config.numMB;
            long chunkSize = config.chunkSize; 
            long iters = config.repetitions;

            DiskDeviceContract.Imp imp;
            string! devName = (!)config.deviceName;

            imp = OpenDevice(devName);
            if (null == imp) {
                return 1;
            }

            for (long i = 0; i < iters; i++) {
                long startIrqCount = ProcessService.GetKernelInterruptCount();
                long startSwitchCount = ProcessService.GetContextSwitchCount();
                long startKernelGcCount = ProcessService.GetKernelGcCount();
                int  startGcCount;
                long startGcMillis;
                long startGcBytes;
                GC.PerformanceCounters(out startGcCount,
                                       out startGcMillis,
                                       out startGcBytes);

                long cycles;
                long ticks;

                imp.SendReadPerf( (int) numMB, (int) chunkSize);
                imp.RecvAckReadPerf(out cycles, out ticks);


                int  endGcCount;
                long endGcMillis;
                long endGcBytes;
                GC.PerformanceCounters(out endGcCount,
                                       out endGcMillis,
                                       out endGcBytes);

                DisplayPerf(ticks, cycles, (ulong) numMB, (ulong)chunkSize);
                Console.WriteLine("[AppGC :- cnt {0} bytes {1} Kern: ints {2} swi {3} gcs {4}]",
                endGcCount - startGcCount,
                endGcBytes - startGcBytes,
                ProcessService.GetKernelInterruptCount() - startIrqCount,
                ProcessService.GetContextSwitchCount() - startSwitchCount,
                ProcessService.GetKernelGcCount() - startKernelGcCount);
            }

            delete imp;
            return 0;
        }
    }
}