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

using System;
using System.Text;
using System.Threading;
using System.Collections;

using Microsoft.Singularity;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.Security;
using Microsoft.Singularity.Security.SDS;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.V1.Services;
using Microsoft.SingSharp;

namespace Microsoft.Singularity.Directory
{
    public class SdsUtilsAcl
    {

//------------------------------------------------------------------------------
// QueryACL
//------------------------------------------------------------------------------
        public static  bool QueryACL (string! path, bool effective,
                                      DirectoryServiceContract.Imp:Ready! ds,
                                      out Acl aclOut, out ErrorCode errorOut )
        {
            errorOut = ErrorCode.Unknown;
            aclOut = Acl.nullAcl;
            char[]! in ExHeap exPath;
            exPath = Bitter.FromString2(path);
            bool results;

            if (!ds.InState(DirectoryServiceContract.Ready.Value)) DebugStub.Break();
            ds.SendQueryACL(exPath, effective);
            try {
                switch receive {
                    case ds.NakQueryACL(error):
  // Failed: no such leaf node, or leaf node is not a file
                        errorOut = error;
                        return false;

                    case ds.AckQueryACL(nodePattern, descendantPattern):
                        // Success
                        // unmarshall ACL
                        errorOut = ErrorCode.NoError;
                        string res1 = Bitter.ToString(nodePattern);
                        string res2 = Bitter.ToString(descendantPattern);
                        aclOut = new Acl(res1, res2);
                        delete nodePattern;
                        delete descendantPattern;
                        return true;
                        break;

                    case ds.ChannelClosed():
  // Directory channel closed unexpectedly
                        errorOut = ErrorCode.ChannelClosed;
                        return false;
                        break;

                    case unsatisfiable :
                        // should never happen.
                        errorOut = ErrorCode.Unsatisfiable;
                        return false;
                        break;

                    case ds.NakQueryACLReparse(i_prefix,
                                                    i_suffix,
                                                    linkFound):
                        // traversed either a mount point or a link
                        string pre = Bitter.ToString2(i_prefix);
                        string suf = Bitter.ToString(i_suffix);
                        delete i_prefix;
                        delete i_suffix;

                        DebugStub.WriteLine("QueryACL.reparse: pre={0}, suf={1}, linkfound ={2}",
                                            __arglist(pre,suf, linkFound? "true": "false"));

                        // Either a SymLink or a non-leaf provider node has been encountered.
                        if (linkFound) {
                            //reissue search
                            DebugStub.WriteLine("link: issuing rebind to{0}",__arglist(pre));
                            return QueryACL(pre, effective, ds, out aclOut, out errorOut);
                        }
                        else {
                            // Bind to the ServiceProvider and continue search
                            DirectoryServiceContract.Imp dsImp =
                                SdsUtils.GetDSPChannel(ds, pre, out errorOut);

                            if (dsImp == null) {
                                return false; // failure; code already in errorOut
                            }

                            try {
                                if (null == suf) {
                                    // Strange to get a NakCreateDirectoryReparse here!
                                    errorOut = ErrorCode.Unknown;
                                    return false;
                                }
                                else {
                                    return QueryACL(suf, effective, dsImp, out aclOut, out errorOut);
                                }
                            }
                            finally {
                                SdsUtils.ReleaseDSPChannel(pre, dsImp);
                            }
                        } //!linkFound
                        break;
                } //switch
            }
            finally {
            if (!ds.InState(DirectoryServiceContract.Ready.Value)) DebugStub.Break();
            }
        } //QueryACL

//------------------------------------------------------------------------------
// StoreACL
//------------------------------------------------------------------------------
        public static  bool StoreACL (string! path, Acl acl,
                                      DirectoryServiceContract.Imp:Ready! ds,
                                      out ErrorCode errorOut )
        {
            errorOut = ErrorCode.Unknown;
            char[]! in ExHeap exPath;
            char[] in ExHeap exAclStr1, exAclStr2;
            exPath = Bitter.FromString2(path);
            exAclStr1 = Bitter.FromString(acl.Node);
            exAclStr2 = Bitter.FromString(acl.Descendant);
            bool results;

            if (!ds.InState(DirectoryServiceContract.Ready.Value)) DebugStub.Break();
            ds.SendStoreACL(exPath, exAclStr1, exAclStr2);
            try {
                switch receive {
                    case ds.NakStoreACL(error):
                        // Failed: no such leaf node, or leaf node is not a file
                        errorOut = error;
                        return false;

                    case ds.AckStoreACL():
                        // Success
                        errorOut = ErrorCode.NoError;
                        return true;
                        break;

                    case ds.ChannelClosed():
                        // Directory channel closed unexpectedly
                        errorOut = ErrorCode.ChannelClosed;
                        return false;
                        break;

                    case unsatisfiable :
                        // should never happen.
                        errorOut = ErrorCode.Unsatisfiable;
                        return false;
                        break;

                    case ds.NakStoreACLReparse(i_prefix,
                                                    i_suffix,
                                                    linkFound) :
                        // traversed either a mount point or a link
                        string pre= Bitter.ToString2(i_prefix);
                        string suf= Bitter.ToString(i_suffix);
                        delete i_prefix;
                        delete i_suffix;

                        DebugStub.WriteLine("StoreACL.reparse: pre={0}, suf={1}, linkfound ={2}",
                                            __arglist(pre, suf, linkFound? "true": "false"));

                        // Either a SymLink or a non-leaf provider node has been encountered.
                        if (linkFound) {
                            //reissue search
                            DebugStub.WriteLine("link: issuing rebind to{0}",__arglist(pre));
                            return StoreACL(pre, acl, ds, out errorOut);
                        }
                        else {
                            // Bind to the ServiceProvider and continue search
                            DirectoryServiceContract.Imp dsImp =
                                SdsUtils.GetDSPChannel(ds, pre, out errorOut);

                            if (dsImp == null) {
                                return false; // failure; code already in errorOut
                            }

                            try {
                                if (null == suf) {
                                    // Strange to get a NakCreateDirectoryReparse here!
                                    errorOut = ErrorCode.Unknown;
                                    return false;
                                }
                                else {
                                    return StoreACL(suf, acl, dsImp, out errorOut);
                                }
                            }
                            finally {
                                SdsUtils.ReleaseDSPChannel(pre, dsImp);
                            }
                        } //!linkFound
                        break;
                } //switch
            }
            finally {
            if (!ds.InState(DirectoryServiceContract.Ready.Value)) DebugStub.Break();
            }
        } //StoreAcl
    } // class
}