////////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  Note:   Simple Windows XP-like TaskList program.
//
using System;
using System.Collections;
using System.Runtime.CompilerServices;
using System.Threading;

using Microsoft.Singularity;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.Diagnostics.Contracts;
using Microsoft.Singularity.Configuration;
using Microsoft.Singularity.Io;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.V1.Services;
using Microsoft.SingSharp;

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

namespace Microsoft.Singularity.Applications
{
    [ConsoleCategory(HelpMessage="Tasklist [options]  Displays XP-like task information",
                     DefaultAction=true)]
    internal sealed class Parameters
    {
        [InputEndpoint("data")]
        public readonly TRef<UnicodePipeContract.Exp:READY> Stdin;

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

        [Endpoint]
        public readonly TRef<ProcessContract.Imp:Start> processRef;

        [Endpoint]
        public readonly TRef<MemoryContract.Imp:Start> memoryRef;

        [Endpoint]
        public readonly TRef<ChannelContract.Imp:Start> channelRef;

        [BoolParameter( "d", Default=false , HelpMessage="Dumps output and PageTable to Debugger.")]
        internal bool dumpTable;

        [BoolParameter( "c", Default=false , HelpMessage="Displays channels per process.")]
        internal bool displayChannels;

        [BoolParameter( "t", Default=false , HelpMessage="Displays ThreadIds per process.")]
        internal bool displayThreads;

        [LongParameter( "r", Default=-1, HelpMessage="Repeat every <n> seconds")]
        internal long pauseSeconds;

        reflective internal Parameters();

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

    internal class TaskList
    {
        private class ProcessData
        {
            public int id;
            public string name;
            public long memBytes;
            public long peakMemBytes;
            public long commMemBlocks;
            public long commMemBytes;
            public long handlePages;
            public int[] tids; 
            public int parentID;
            
            public ProcessData() {
                tids = null; 
            }
        }

        private class ChannelData
        {
            public int ChannelId;
            public int ImpProcessId;
            public int ExpProcessId;
            public int MessagesDeliveredToImp;
            public int MessagesDeliveredToExp;
        }
        
        private class TaskListException : Exception
        {
            internal TaskListException(string errorMessage)
                : base(errorMessage)
            {
            }
        }

        private static int []! GetProcessIDs(ProcessContract.Imp:ReadyState! imp)
        {
            int [] ids = null;
            int[]! in ExHeap xids;
            imp.SendGetProcessIDs();
            imp.RecvProcessIDs(out xids);
            // REVIEW: The kernel process is being returned twice so we're
            // skipping one of the entries if the process ID matches.
            int startIndex = 0;
            if (xids[0] == xids[1])
                startIndex++;
            ids = new int[xids.Length - startIndex];
            for (int i = startIndex; i < xids.Length; i++) {
                ids[i - startIndex] = xids[i];
            }
            delete xids;
            return ids;
        }

        private static int [] GetProcessThreadIDs(ProcessContract.Imp:ReadyState! imp, int procID)
        {
            imp.SendGetProcessThreadIDs(procID);
            int [] retVal = null; 
            
            switch receive {
                case imp.NotFound() :
                    break;

                case imp.ProcessThreadIDs(int[]! in ExHeap tids) :
                    retVal = new int[tids.Length];
                    for (int i = 0; i < tids.Length; i++) {
                        retVal[i] = tids[i]; 
                    } 
                    delete tids;
                    break;

                case imp.ChannelClosed() :
                    throw new TaskListException("GetProcessThreadIDs: imp channel closed");
            }
            return retVal; 
        } 

        private static string []! GetProcessNames(ProcessContract.Imp:ReadyState! imp, int []! ids)
        {
            string [] names = new string[ids.Length];
            for (int i = 0; i < ids.Length; i++) {
                imp.SendGetProcessName(ids[i]);

                switch receive {
                    case imp.NotFound() :
                        break;

                    case imp.ProcessName(char[]! in ExHeap procName) :
                        names[i] = Bitter.ToString(procName);
                        delete procName;
                        break;

                    case imp.ChannelClosed() :
                        throw new TaskListException("GetProcessNames: imp channel closed");
                }
            }
            return names;
        }

        private static int []! GetParentIDs(ProcessContract.Imp:ReadyState! imp, int []! ids)
        {
            int [] parentIDs = new int[ids.Length];
            for (int i = 0; i < ids.Length; i++) {
                imp.SendGetParentID(ids[i]);

                switch receive {
                    case imp.NotFound() :
                        parentIDs[i] = -1;
                        break;

                    case imp.ParentID(int parentID) :
                        parentIDs[i] = parentID;
                        break;

                    case imp.ChannelClosed() :
                        throw new TaskListException("GetParentID: imp channel closed");
                }
            }
            return parentIDs;
        }

        private static void GetMemoryUsage(MemoryContract.Imp:ReadyState! imp, ProcessData[]! processData)
        {
            for (int i = 0; i < processData.Length; i++) {
                ProcessData! pd = (!)processData[i];
                imp.SendGetProcessUsedMemory(pd.id);
                imp.RecvMemory(out pd.memBytes);

                imp.SendGetProcessPeakMemory(pd.id);
                imp.RecvMemory(out pd.peakMemBytes);

                imp.SendProcessUsedCommunicationHeap(pd.id);
                imp.RecvBlocksAndTotal(out pd.commMemBlocks, out pd.commMemBytes);

                imp.SendGetProcessHandlePages(pd.id);
                imp.RecvPages(out pd.handlePages);
            }
        }

        private static ProcessData[]! GetProcessData(Parameters! config)
        {
            ProcessContract.Imp imp = config.processRef.Acquire(); 
            if (imp == null) {
                throw new TaskListException("Error: Unable to bind to " + ProcessContract.ModuleName);
            }
            int [] ids = GetProcessIDs(imp);
            string [] names = GetProcessNames(imp, ids);
            int [] parentIDs = GetParentIDs(imp, ids);
            

            ProcessData [] processData= new ProcessData[ids.Length];
            for (int i = 0; i < ids.Length; i++) {
                ProcessData! pd = new ProcessData();
                pd.id = ids[i];
                pd.name = names[i];
                pd.parentID = parentIDs[i];
                pd.tids = GetProcessThreadIDs(imp, ids[i]); 
                processData[i] = pd;
            }

            config.processRef.Release(imp);

            MemoryContract.Imp impMem = config.memoryRef.Acquire();
            if (impMem == null) {
                throw new TaskListException("Error: Unable to bind to " + MemoryContract.ModuleName);
            }
            GetMemoryUsage(impMem, processData);

            config.memoryRef.Release(impMem);

            return processData;
        }

        private static ChannelData []! GetChannelData(ProcessData [] processData, Parameters! config)
        {
            ChannelContract.Imp imp = config.channelRef.Acquire();
            if (imp == null) {
                throw new TaskListException("Error: Unable to bind to " + ChannelContract.ModuleName);
            }

            ChannelInfo[]! in ExHeap channels;
            imp.SendGetChannels();
            imp.RecvChannels(out channels);

            ChannelData [] channelData = new ChannelData[channels.Length];
            for (int i = 0; i < channels.Length; i++) {
                ChannelData cd = new ChannelData();
                channelData[i] = cd;

                cd.ChannelId = channels[i].ChannelId;
                cd.ImpProcessId = channels[i].ImpProcessId;
                cd.ExpProcessId = channels[i].ExpProcessId;
                cd.MessagesDeliveredToImp = channels[i].MessagesDeliveredToImp;
                cd.MessagesDeliveredToExp = channels[i].MessagesDeliveredToExp;
            }
            config.channelRef.Release(imp);
            delete channels;

            return channelData;
        }

        private static ArrayList! GetImportedChannels(ChannelData[]! channelData, int processId)
        {
            ArrayList channelList = new ArrayList();
            for (int i = 0; i < channelData.Length; i++) {
                ChannelData cd = channelData[i];
                if (cd == null) continue;
                if (cd.ImpProcessId == processId) {
                    channelList.Add(channelData[i]);
                }
            }
            return channelList;
        }

        private static ArrayList! GetExportedChannels(ChannelData[]! channelData, int processId)
        {
            ArrayList channelList = new ArrayList();
            for (int i = 0; i < channelData.Length; i++) {
                ChannelData cd = channelData[i];
                if (cd == null) continue;
                if (cd.ExpProcessId == processId) {
                    channelList.Add(channelData[i]);
                }
            }
            return channelList;
        }

        /// <summary>
        /// Use this method to write output to both the screen and the debugger if toDebugger is true.
        /// </summary>
        private static void WriteLine(bool toDebugger, string format, params object[] args) {
            string s = String.Format(format, args);
            Console.WriteLine(s);
            if (toDebugger) {
                DebugStub.WriteLine(s);
            }
        } 

        private static void WriteLine(bool toDebugger) {
            Console.WriteLine();
            if (toDebugger) {
                DebugStub.WriteLine();
            }
        } 

        internal static int AppMain(Parameters! config)
        {
            ProcessData [] processData;
            ChannelData [] channelData;

            // Set the default options
            bool displayChannels = config.displayChannels;
            bool displayThreads = config.displayThreads;
            bool dumpTable = config.dumpTable; 
            int pauseSeconds = (int) config.pauseSeconds;


            ProcessContract.Imp imp1 = config.processRef.Acquire(); 
            imp1.RecvReady();
            config.processRef.Release(imp1); 

            MemoryContract.Imp imp2 = config.memoryRef.Acquire(); 
            imp2.RecvReady();
            config.memoryRef.Release(imp2); 

            ChannelContract.Imp imp3 = config.channelRef.Acquire(); 
            imp3.RecvReady();
            config.channelRef.Release(imp3); 
            
            do
            {
                // Retrieve the process and channel data
                try {
                    processData = GetProcessData(config);
                }
                catch (TaskListException ex) {
                    Console.WriteLine("Error retrieving process data.");
                    Console.WriteLine(ex.ToString());
                    return 1;
                }
                try {
                    channelData = GetChannelData(processData,config);
                }
                catch (TaskListException ex) {
                    Console.WriteLine("Error retrieving channel data.");
                    Console.WriteLine(ex.ToString());
                    return 1;
                }

                // Prep for display
                Hashtable processName = new Hashtable(processData.Length);
                for (int i = 0; i < processData.Length; i++) {
                    ProcessData pd = processData[i];
                    if (pd == null) continue;
                    processName.Add(pd.id, pd.name);
                }

                // Display the results
                Console.WriteLine();
                WriteLine(dumpTable, "PID Task Name           Mem Usage Peak Mem Shared Mem Chan Imp Exp HP  Parent");
                WriteLine(dumpTable, "=== =================== ========= ======== ========== ======== === === ======");

                for (int i = 0; i < processData.Length; i++) {
                    ProcessData pd = processData[i];
                    if (pd == null) continue;

                    ArrayList importedChannels = GetImportedChannels(channelData, pd.id);
                    ArrayList exportedChannels = GetExportedChannels(channelData, pd.id);

                    WriteLine(dumpTable, "{0,3} {1,-19} {2,7} K {3,6} K {4,8} K {5,8} {6,3} {7,3} {8,5}", pd.id,
                                             pd.name, pd.memBytes / 1024, pd.peakMemBytes / 1024,
                                             pd.commMemBytes / 1024, importedChannels.Count, exportedChannels.Count,
                                             pd.handlePages, pd.parentID);

                    if (displayThreads) {
                        if (pd.tids != null && pd.tids.Length > 0) {
                            for (int j = 0; j < pd.tids.Length; j++) {
                                WriteLine(dumpTable, "     tid -> {0}",pd.tids[j]); 
                            }
                        }
                    }
                    
                    if (displayChannels) {
                        // First display the imports
                        for (int j = 0; j < importedChannels.Count; j++) {
                            ChannelData data = (ChannelData!) importedChannels[j];
                            WriteLine(dumpTable, "     -> {0} (cid={1}, msgs={2})",
                                      processName[data.ExpProcessId], data.ChannelId, data.MessagesDeliveredToImp);
                        }
                        // Then display the exports
                        for (int j = 0; j < exportedChannels.Count; j++) {
                            ChannelData data = (ChannelData!) exportedChannels[j];
                            WriteLine(dumpTable, "     <- {0} (cid={1}, msgs={2})",
                                      processName[data.ImpProcessId], data.ChannelId, data.MessagesDeliveredToExp);
                        }
                    }
                }
                if (dumpTable) {
                    AppRuntime.DumpPageTable(); 
                }
                if (pauseSeconds > 0) {
                    Thread.Sleep(1000 * (int)pauseSeconds);
                }
            } while (pauseSeconds >= 0);

            return 0;
        }
    }
}