///////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  File:   Diagnostics.sg
//
//  Note:   The Singularity Diagnostics web application
//

using Microsoft.SingSharp;
using Microsoft.SingSharp.Runtime;
using Microsoft.Singularity.Diagnostics.Contracts;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.WebApps;
using Microsoft.Singularity.WebApps.Contracts;
using Microsoft.Singularity.PingPong.Contracts;
using System;
using System.Collections;
using System.Diagnostics;
using System.Text;
using System.Web;

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

namespace Microsoft.Singularity.WebApps
{
    [Category("WebApp")]
    internal sealed class Parameters
    {
        [Endpoint]
        public readonly TRef<WebAppContract.Exp:Start> webAppRef;

#if false 
        [Endpoint]
        public readonly TRef<DirectoryServiceContract.Imp:Start> nsRef;
#endif 
        reflective private Parameters();
    }
    
    public class DiagnosticsWebApp : IWebApp
    {
        private TRef<ChannelContract.Imp:ReadyState> m_ChanConn;
        private TRef<ProcessContract.Imp:ReadyState> m_ProcConn;
        private TRef<MemoryContract.Imp:ReadyState> m_MemConn;
        private TRef<PingContract.Imp:PendingState> m_PingConn;

        private class ProcPairInfo
        {
            public int numChannels;
            public int numMessages;
        }

        private Hashtable m_ProcPairInfoTable; // State from the last snapshot

        public DiagnosticsWebApp()
        {
            ChannelContract.Imp! impChanConn;
            ChannelContract.Exp! expChanConn;
            ChannelContract.NewChannel(out impChanConn, out expChanConn);

            ProcessContract.Imp! impProcConn;
            ProcessContract.Exp! expProcConn;
            ProcessContract.NewChannel(out impProcConn, out expProcConn);

            MemoryContract.Imp! impMemConn;
            MemoryContract.Exp! expMemConn;
            MemoryContract.NewChannel(out impMemConn, out expMemConn);

            DirectoryServiceContract.Imp epNS = DirectoryService.NewClientEndpoint();

            try
            {
                // Look up the general Diagnostics contract (this will go away!)
                epNS.SendBind(Bitter.FromString2(ChannelContract.ModuleName), expChanConn);
                switch receive
                {
                    case epNS.NakBind(ServiceContract.Exp:Start rejectedEP, error) :
                        delete impChanConn;
                        delete rejectedEP;
                        break;

                    case epNS.AckBind() :
                        impChanConn.RecvReady();
                        m_ChanConn = new TRef<ChannelContract.Imp:ReadyState>(impChanConn);
                        // success
                        break;

                    case epNS.ChannelClosed() :
                        throw new Exception("epNS channel closed");
                }

                // Look up the specific diagnostic modules we need
                epNS.SendBind(Bitter.FromString2(ProcessContract.ModuleName), expProcConn);

                switch receive
                {
                    case epNS.NakBind(ServiceContract.Exp:Start rejectedEP, error) :
                        delete impProcConn;
                        delete rejectedEP;
                        break;

                    case epNS.AckBind() :
                        impProcConn.RecvReady();
                        m_ProcConn = new TRef<ProcessContract.Imp:ReadyState>(impProcConn);
                        // success
                        break;

                    case epNS.ChannelClosed() :
                        throw new Exception("epNS channel closed");
                }

                epNS.SendBind(Bitter.FromString2(MemoryContract.ModuleName), expMemConn);

                switch receive
                {
                    case epNS.NakBind(ServiceContract.Exp:Start rejectedEP, error) :
                        delete impMemConn;
                        delete rejectedEP;
                        break;

                    case epNS.AckBind() :
                        impMemConn.RecvReady();
                        m_MemConn = new TRef<MemoryContract.Imp:ReadyState>(impMemConn);
                        // success
                        break;

                    case epNS.ChannelClosed() :
                        throw new Exception("epNS channel closed");
                }
            }
            finally
            {
                delete epNS;
            }

            // Spawn the Ping child process so we can do simulated IPC bursts
            PingContract.Imp! childImp;
            PingContract.Exp! childExp;
            PingContract.NewChannel(out childImp, out childExp);

            string[] args = new string[1];
            args[0] = "ChildPing.x86";
            Process child = new Process(args, (Endpoint * in ExHeap)childExp);
            child.Start();

            childImp.RecvPingReady();
            childImp.SendStartPingPong(1);
            m_PingConn = new TRef<PingContract.Imp:PendingState>(childImp);
        }

        public void ProcessRequest(IHttpRequest! request)
        {
            if (m_ChanConn == null)
            {
                ReportInternalError(request, "No channel to the channel diagnostic module");
            }
            else if (m_ProcConn == null)
            {
                ReportInternalError(request, "No channel to the process diagnostic module");
            }
            else if (m_MemConn == null)
            {
                ReportInternalError(request, "No channel to the memory diagnostic module");
            }
            else if (m_PingConn == null)
            {
                ReportInternalError(request, "No channel to the pingpong child apps");
            }
            else
            {
                ChannelContract.Imp impChanConn = m_ChanConn.Acquire();
                ProcessContract.Imp impProcConn = m_ProcConn.Acquire();
                MemoryContract.Imp impMemConn = m_MemConn.Acquire();
                PingContract.Imp impPingConn = m_PingConn.Acquire();

                Console.Write("1");

                try
                {
                    string uri = request.GetUriPath();

                    if (uri.EndsWith("diagram.png"))
                    {
                        // Serve the image
                        request.SendStatus(200, "OK");
                        request.SendHeader("Content-type", "image/jpeg");
                        request.SendBodyData(DiagnosticImage.ImageData);
                    }
                    else if (uri.IndexOf("pingpong") > 0)
                    {
                        Console.Write("2");

                        string queryString = request.GetQueryString();
                        int numReps = 10000;

                        if (queryString != null)
                        {
                            string paramPreamble = "numreps=";
                            int preambleIndex = queryString.IndexOf(paramPreamble);

                            if (preambleIndex != -1)
                            {
                                int nextParamIndex = queryString.IndexOf(';', preambleIndex);
                                string numRepsStr;
                                int start = preambleIndex + paramPreamble.Length;

                                if (nextParamIndex == -1)
                                {
                                    numRepsStr = queryString.Substring(start);
                                }
                                else
                                {
                                    numRepsStr = queryString.Substring(start, nextParamIndex - start);
                                }

                                numReps = Int32.Parse(numRepsStr);
                            }
                        }

                        // Start the ping-pong exchange
                        impPingConn.RecvDone();
                        impPingConn.SendStartPingPong(numReps);

                        // Serve the reply
                        request.SendStatus(200, "OK");
                        request.SendHeader("Content-type", "text/plain");
                        request.SendBodyData(Encoding.ASCII.GetBytes("Started " + numReps + " ping-pong exchanges."));
                    }
                    else if (uri.IndexOf("dumpheap") > 0)
                    {
                        Console.Write("4");
                        ServeHeapDump(impMemConn, request);
                    }
                    else
                    {
                        Console.Write("<");
                        ServeMasterPage(impChanConn, impProcConn, impMemConn, request);
                        Console.Write(">");
                    }

                }
                catch(Exception e)
                {
                    ReportInternalError(request, "Caught an exception: " + e);
                }
                finally
                {
                    m_PingConn.Release(impPingConn);
                    m_MemConn.Release(impMemConn);
                    m_ProcConn.Release(impProcConn);
                    m_ChanConn.Release(impChanConn);
                }
            }

            request.Done();
        }


        private void ServeMasterPage(ChannelContract.Imp:ReadyState! impChanConn,
                                     ProcessContract.Imp:ReadyState! impProcConn,
                                     MemoryContract.Imp:ReadyState! impMemConn,
                                     IHttpRequest! request)
        {
            // Serve the master page

            // -----------------------------------------------
            // First, get all our data in order.
            long maxMemory, usedMemory, freeMemory;
            long totalCommBlocks, totalCommBytes;

            Console.Write("3");
            impMemConn.SendGetFreeMemory();
            Console.Write("a");
            impMemConn.RecvMemory(out freeMemory);
            Console.Write("b");
            impMemConn.SendGetUsedMemory();
            Console.Write("c");
            impMemConn.RecvMemory(out usedMemory);
            Console.Write("d");
            impMemConn.SendGetMaxMemory();
            Console.Write("e");
            impMemConn.RecvMemory(out maxMemory);
            Console.Write("f");
            impMemConn.SendTotalUsedCommunicationHeap();
            Console.Write("g");
            impMemConn.RecvBlocksAndTotal(out totalCommBlocks, out totalCommBytes);
            Console.Write("4");

            // This structure hashes process 2-tuples to the
            // ProcPairInfo structure. The key
            // is "procA:procB", using the process names,
            // with the lower-ID process on the left.
            Hashtable procPairTable = new Hashtable();

            // This table lets us look up process names
            Hashtable procNames = new Hashtable();

            // Fill in the name table
            int[]! in ExHeap procIDs;
            impProcConn.SendGetProcessIDs();
            impProcConn.RecvProcessIDs(out procIDs);
            Console.Write("5");

            try
            {
                for (int i = 0; i < procIDs.Length; ++i)
                {
                    impProcConn.SendGetProcessName(procIDs[i]);

                    switch receive
                    {
                        case impProcConn.NotFound() :
                            // Do nothing; go to the next ID
                            break;

                        case impProcConn.ProcessName(char[]! in ExHeap procName) :
                            // Drop the name into the table
                            int procID = procIDs[i];
                            string valCopy = Bitter.ToString(procName);
                            delete procName;
                            procNames[procID] = valCopy;
                            break;

                        case impProcConn.ChannelClosed():
                            throw new Exception("impProcConn channel closed");
                    }
                }
            }
            finally
            {
                delete procIDs;
            }
            Console.Write("6");

            // Now fill in the table of channels
            ChannelInfo[]! in ExHeap channels;
            impChanConn.SendGetChannels();
            impChanConn.RecvChannels(out channels);
            Console.Write("7");

            try
            {
                for (int i = 0; i < channels.Length; i++)
                {
                    int leftProcID, rightProcID;
                    string leftProcName, rightProcName;

                    // Ignore loop channels for now
                    if (channels[i].ImpProcessId != channels[i].ExpProcessId)
                    {
                        if (channels[i].ImpProcessId < channels[i].ExpProcessId)
                        {
                            leftProcID = channels[i].ImpProcessId;
                            rightProcID = channels[i].ExpProcessId;
                        }
                        else
                        {
                            leftProcID = channels[i].ExpProcessId;
                            rightProcID = channels[i].ImpProcessId;
                        }

                        leftProcName = procNames[leftProcID] as string;
                        rightProcName = procNames[rightProcID] as string;

                        if ((leftProcName != null) && (rightProcName != null))
                        {
                            string compoundName = leftProcName + ":" + rightProcName;
                            ProcPairInfo pairInfo = procPairTable[compoundName] as ProcPairInfo;

                            if (pairInfo == null)
                            {
                                pairInfo = new ProcPairInfo();
                            }

                            // Add to the list of channels between these processes
                            pairInfo.numChannels++;
                            pairInfo.numMessages += channels[i].MessagesDeliveredToExp + channels[i].MessagesDeliveredToImp;
                            procPairTable[compoundName] = pairInfo;
                        }
                    }
                }
            }
            finally
            {
                // This is done below, where we dump the channels; uncomment this if we get rid of that HTML.
                //delete channels;
            }
            Console.Write("8");

            // -----------------------------------------------
            // Now generate the page.
            request.SendStatus(200, "OK");
            request.SendHeader("Content-type", "text/html");
            request.SendHeader("charset", "utf-8");

            Console.Write("9");

            // Serve up the canned page preamble. This leaves us in a <script> context.
            request.SendBodyData(MasterPage.HTMLData);

            // Drop in Javascript statements to drive the dynamic portions of the page

            foreach (string! pairName in procPairTable.Keys)
            {
                ProcPairInfo info = (ProcPairInfo!)procPairTable[pairName];
                ProcPairInfo prevInfo = null;

                if (m_ProcPairInfoTable != null) // might be first run
                {
                    prevInfo = m_ProcPairInfoTable[pairName] as ProcPairInfo; // might be null
                }

                int msgDelta;

                if (prevInfo != null)
                {
                    msgDelta = info.numMessages - prevInfo.numMessages;
                }
                else
                {
                    msgDelta = info.numMessages;
                }

                // The scaling value of 3 means that 1,000 tops out the thermometer; change as
                // appropriate!
                double scaledValue = (msgDelta <= 0
                                      ? 0
                                      : 3 * (Math.Sqrt(msgDelta)));

                int roundedValue = (int)scaledValue;

                if (roundedValue < 80)
                {
                    request.SendBodyData(Encoding.ASCII.GetBytes("setThermometerValue(\"" + pairName + "\", \"" + roundedValue + "%\");\n"));
                }
                else
                {
                    request.SendBodyData(Encoding.ASCII.GetBytes("setThermometerToOverflow(\"" + pairName + "\", \"" + roundedValue + "%\");\n"));
                }

                request.SendBodyData(Encoding.ASCII.GetBytes("setThermometerLabel(\"" + pairName + "\", \"(" + info.numMessages + " / " + info.numChannels + ")\");\n"));
            }

            // Stash our new snapshot for next time
            m_ProcPairInfoTable = procPairTable;

            // Push data into the memory thermometer
            request.SendBodyData(Encoding.ASCII.GetBytes("setThermometerValue(\"usedMemory\", \"" + ((usedMemory * 100) / freeMemory) + "%\");\n"));
            request.SendBodyData(Encoding.ASCII.GetBytes("setThermometerLabel(\"usedMemory\", \"(" + usedMemory + " of " + maxMemory + " used, " + freeMemory + " bytes free)\");\n"));

            // Don't forget to close out the <script> context
            request.SendBodyData(Encoding.ASCII.GetBytes("</script>"));

            //
            // Preserve some of the old-style HTML tables for now...
            //

            // Send total amount of communication heap blocks and memory
            request.SendBodyData(Encoding.ASCII.GetBytes("<hr><h1>Communication heap used</h1><table border=2>"));
            request.SendBodyData(Encoding.ASCII.GetBytes("<tr><td>Total blocks</td><td>" + totalCommBlocks + "</td></tr>"));
            request.SendBodyData(Encoding.ASCII.GetBytes("<tr><td>Total bytes</td><td>" + totalCommBytes + "</td></tr>"));

            request.SendBodyData(Encoding.ASCII.GetBytes("</table>"));

            // Dump the table of processes with their names
            request.SendBodyData(Encoding.ASCII.GetBytes("<hr><h1>Processes</h1><table border=2>"));
            request.SendBodyData(Encoding.ASCII.GetBytes("<tr><td>PID</td><td>Image</td></tr>"));
            foreach (int procId in procNames.Keys)
            {
                string procName = (string)procNames[procId];
                request.SendBodyData(Encoding.ASCII.GetBytes("<tr><td>" + procId + "</td><td>" + procName + "</td></tr>"));
            }
            request.SendBodyData(Encoding.ASCII.GetBytes("</table>"));


            // Dump the table of channels that exist at the moment
            request.SendBodyData(Encoding.ASCII.GetBytes("<hr><h1>Channels</h1><table border=2>"));
            request.SendBodyData(Encoding.ASCII.GetBytes("<tr><td>CID</td><td>Exp PID</td><td>Imp PID</td><td>Exp Bytes</td><td>Imp Bytes</td></tr>"));

            for (int i = 0; i < channels.Length; i++)
            {
                request.SendBodyData(Encoding.ASCII.GetBytes("<tr><td>"+
                                                             channels[i].ChannelId+
                                                             "</td><td>"+
                                                             channels[i].ExpProcessId+
                                                             "</td><td>"+
                                                             channels[i].ImpProcessId+
                                                             "</td><td>"+
                                                             channels[i].MessagesDeliveredToExp+
                                                             "</td><td>"+
                                                             channels[i].MessagesDeliveredToImp+
                                                             "</td></tr>"));
            }

            // Don't forget this...
            delete channels;

            request.SendBodyData(Encoding.ASCII.GetBytes("</table></body></html>"));
        }

        private void ServeHeapDump(MemoryContract.Imp:ReadyState! impMemConn,
                                   IHttpRequest! request)
        {
            request.SendStatus(200, "OK");
            request.SendHeader("Content-type", "text/html");
            request.SendHeader("charset", "utf-8");

            request.SendBodyData(Encoding.ASCII.GetBytes("<html><head><title>ExHeap dump</title></head><body><h1>ExHeap Dump</h1><table border=2><tr><td>Ptr</td><td>PID</td><td>Type</td><td>Size</td></tr>"));

            Hashtable procCounts = new Hashtable();
            MemoryContract.BlockInfo[]! in ExHeap dump;

            impMemConn.SendDumpExHeap();
            impMemConn.RecvExHeapDump(out dump);

            for (int i = 0; i < dump.Length; i++)
            {
                string text = String.Format("<tr><td>{0:x}</td><td>{1}</td><td>{2:x}</td><td>{3}</td></tr>", dump[i].ptrVal, dump[i].ownerProcID, dump[i].type, dump[i].size);
                request.SendBodyData(Encoding.ASCII.GetBytes(text));
                object count = procCounts[dump[i].ownerProcID];

                if (count == null)
                {
                    procCounts[dump[i].ownerProcID] = 1;
                }
                else
                {
                    procCounts[dump[i].ownerProcID] = ((int)count) + 1;
                }
            }

            delete dump;

            request.SendBodyData(Encoding.ASCII.GetBytes("</table><hr><h1>Totals by ProcID</h1><table border=2><tr><td>ProcID</td><td>Total Blocks</td></tr>"));

            foreach (DictionaryEntry entry in procCounts)
            {
                request.SendBodyData(Encoding.ASCII.GetBytes("<tr><td>" + entry.Key + "</td><td>" + entry.Value + "</td></tr>"));
            }

            request.SendBodyData(Encoding.ASCII.GetBytes("</table></body></html>"));
        }

        // ======================================================
        // The code below gets used when this webapp is compiled
        // to a stand-alone executable
        internal static int AppMain(Parameters! config)
        {
            //Endpoint * in ExHeap ep = Process.GetStartupEndpoint(0);
            WebAppContract.Exp conn = (config.webAppRef).Acquire();
            if (conn == null) {
                // Wrong contract type!
                return -1;
            }

            conn.SendWebAppReady();
            DiagnosticsWebApp webApp = new DiagnosticsWebApp();
            Driver.ServiceChannel(webApp, conn);
            delete conn;
            return 0;
        }

        private void ReportInternalError(IHttpRequest! request, string! description)
        {
            request.SendStatus(500, "Internal Error");
            request.SendHeader("Content-type", "text/plain");
            request.SendHeader("charset", "utf-8");
            request.SendBodyData(Encoding.ASCII.GetBytes(description));
        }

    }
}