///////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  File:   Type.sg
//
//  Note:
//

using FileSystem.Utils;
using System;
using System.Text;
using System.Threading;
using Microsoft.Singularity;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.FileSystem;
using Microsoft.Singularity.V1.Services;

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="Write contents of file to stdout", 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( "filename", Mandatory=true, Position=0, HelpMessage="Name of file.")]
        internal string fileName;

        [BoolParameter( "q", Default=false, HelpMessage="Quiet Mode: read file but do not write to stdout")]
        internal bool quietMode;

        reflective internal Parameters();

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

    public class Type
    {
        internal static int AppMain(Parameters! config)
        {
            string fileName;
            FileContract.Imp fileImp;
            long readSize = 512;
            long readOffset = 0;
            byte* opt(ExHeap[]) buf = new[ExHeap] byte[readSize];

            byte [] bytes = new byte[readSize];

            DirectoryServiceContract.Imp rootNS = (config.nsRef).Acquire(); 
            if (rootNS == null) { 
                throw new Exception("Unable to acquire handle to the Directory Service root"); 
            } 
            
            rootNS.RecvSuccess();

            fileImp = FileUtils.OpenFile(config.fileName, rootNS);
            delete rootNS; 

            if (fileImp == null){
                delete buf;
                Console.WriteLine("Unable to open file " + config.fileName);
                return 1;
            }

            do
            {
                fileImp.SendRead(buf, 0, readOffset, readSize);
                switch receive
                {
                    case fileImp.AckRead( _buf,  bytesRead,  error) :
                        if (error != 0)
                            Console.WriteLine("Got Error "+error);
                        buf = _buf;
                        Bitter.ToByteArray(buf,0,(int) bytesRead,bytes,0);
                        string str = Encoding.ASCII.GetString(bytes, 0,(int)bytesRead);
                        if (!config.quietMode) Console.Write(str);
                        readOffset += bytesRead;
                        if (bytesRead < readSize) {
                            delete buf;
                            goto end;
                        }
                        break;
                    case fileImp.ChannelClosed() :
                        goto end;
                        break;
                    case unsatisfiable :
                        goto end;
                        break;
                }
            } while (true);
end:        delete fileImp;
            return 0;
        }

    } // class Type
}