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

using Microsoft.SingSharp;
using Microsoft.Singularity.Channels;
using Microsoft.Singularity.Directory;
using Microsoft.Singularity.Io;
using Microsoft.Singularity.Security;

using System;

using MSD = Microsoft.Singularity.Directory;

namespace Microsoft.Singularity.Services.Fat.Fs
{
    public class ComponentTest
    {
        private delegate EnumerationRecords[] in ExHeap EnumerateDelegate(uint whence, out uint nextWhence);

        private static string! DirEntryToHuman(char[]! in ExHeap dn)
        {
            int ls = 7;
            while (dn[ls] == ' ' && ls > 0) {
                ls--;
            }
            string! s = Bitter.ToString2(dn, 0, ls + 1);

            ls = 10;
            while (dn[ls] == ' ' && ls >= 8) {
                ls--;
            }
            if (ls >= 8) {
                s += "." + Bitter.ToString2(dn, 8, ls - 8 + 1);
            }
            return s;
        }

        private static void TestShortName(string! longName,
                                          int attempt,
                                          string! shortName)
        {
            char[]! in ExHeap ln = Bitter.FromString2(longName);
            char[]! in ExHeap sn = new [ExHeap] char [DirectoryEntry.ShortNameEntryLength];
            LongDirectoryEntry.WriteShortNameEntry(ln, attempt, sn);

            string got = DirEntryToHuman(sn);
            DebugStub.Print("Longname = \"{0}\" (\"{1}\") => \"{2}\" ({3})",
                            __arglist(longName, shortName,
                                      got,
                                      Bitter.ToString2(sn))
                            );

            if (got == shortName) {
                DebugStub.Print("        [ Pass ]\n");
            }
            else {
                DebugStub.Print("        [ FAIL ]\n");
                DebugStub.Break();
            }
            delete ln;
            delete sn;
        }

        private static void TestShortName(string! longName, string! shortName)
        {
            TestShortName(longName, 1, shortName);
        }

        private static void TestShortNames()
        {
            TestShortName("The cat sat on the mat", "THECAT~1");
            TestShortName("The cat sat on the mat", "THECAT~1");
            TestShortName("abcdefghi.xyz", "ABCDEF~1.XYZ");
            TestShortName("test1.txt", "TEST1~1.TXT");
            TestShortName("....test1.txt...", "TEST1~1.TXT");
            TestShortName(" . . ..test1.txt.. . ", "TEST1~1.TXT");
            TestShortName("The cat sat on the mat.txt", "THECAT~1.TXT");
            TestShortName("a.b", "A~1.B");
            TestShortName("a.b", "A~1.B");
            TestShortName("a.b", 99, "A~99.B");
            TestShortName("abcdefghi.1234", 700, "ABCD~700.123");
        }

        private static void TestEnumerate(EnumerateDelegate! enumerateDelegate)
        {
            int done = 0;
            for (uint whence = 0; whence != Directory.FinalWhence;) {
                uint nextWhence;

                EnumerationRecords[] in ExHeap er = enumerateDelegate(whence, out nextWhence);
                if (er != null) {
                    for (int i = 0; i < er.Length; i++) {
                        expose (er[i]) {
                            DebugStub.Print(
                                "{0}{1}\n",
                                __arglist(
                                    Bitter.ToString(er[i].Path),
                                    (er[i].Type == NodeType.Directory) ? "/" : "",
                                    er[i].Type)
                                );
                        }
                    }
                    done += er.Length;
                    delete er;
                }
                whence = nextWhence;
            }
            DebugStub.Print("Counted {0} entries.", __arglist(done));
        }

        private static void EnumerateAndFindResults(Directory! d)
        {
            int done = 0;
            for (uint whence = 0; whence != Directory.FinalWhence;) {
                uint nextWhence;

                EnumerationRecords[] in ExHeap er =
                    d.Enumerate2(whence, out nextWhence);
                if (er != null) {
                    for (int i = 0; i < er.Length; i++) {
                        expose (er[i]) {
                            DebugStub.Print(
                                "Validating find for {0}{1}...",
                                __arglist(
                                    Bitter.ToString(er[i].Path),
                                    (er[i].Type == NodeType.Directory) ? "/" : "",
                                    er[i].Type)
                                );
                            bool exists = d.FileOrDirectoryExists(er[i].Path);
                            DebugStub.Print("{0}\n",
                                            __arglist(exists ? "yes" : "no"));
                        }
                    }
                    done += er.Length;
                    delete er;
                }
                whence = nextWhence;
            }
            Console.WriteLine("Counted {0} entries.", done);
        }

        private static void FillInTail(char[]! in ExHeap filename,
                                       int suffix)
        {
            int pos = filename.Length;
            while (suffix != 0 && pos != 0) {
                filename[--pos] = (char)((int)'0' + (suffix % 10));
                suffix /= 10;
            }
        }

        private static bool CreateRangeOfSubDirectories(Directory! d,
                                                        string basename,
                                                        int rangeBegin,
                                                        int rangeLength)
        {
            int digitCount = (int)Math.Log10(rangeBegin + rangeLength);
            char []! in ExHeap fullname =
                Bitter.FromString2(basename + new string(' ', digitCount + 1));

            try {
                int rangeEnd = rangeBegin + rangeLength;
                while (rangeBegin != rangeEnd) {
                    FillInTail(fullname, rangeBegin);

                    MSD.ErrorCode error = d.CreateDirectory(fullname);

                    if (error != MSD.ErrorCode.NoError) {
                        Console.WriteLine(
                            "Failed to create directory {0}: {1}",
                            Bitter.ToString2(fullname),
                            SdsUtils.ErrorCodeToString(error));
                        return false;
                    }
                    rangeBegin++;
                }
            }
            finally {
                delete fullname;
            }
            return true;
        }

        private static bool DeleteRangeOfSubDirectories(Directory! d,
                                                        string basename,
                                                        int rangeBegin,
                                                        int rangeLength)
        {
            int digitCount = (int)Math.Log10(rangeBegin + rangeLength);
            char []! in ExHeap fullname =
                Bitter.FromString2(basename + new string(' ', digitCount + 1));

            try {
                int rangeEnd = rangeBegin + rangeLength;
                while (rangeBegin != rangeEnd) {
                    FillInTail(fullname, rangeBegin);

                    MSD.ErrorCode error = d.DeleteDirectory(fullname);

                    if (error != MSD.ErrorCode.NoError) {
                        Console.WriteLine(
                            "Failed to delete directory {0}: {1}",
                            Bitter.ToString2(fullname),
                            SdsUtils.ErrorCodeToString(error));
                        return false;
                    }
                    rangeBegin++;
                }
            }
            finally {
                delete fullname;
            }
            return true;
        }

        private static char[]! in ExHeap GetTreeNodeName(int count, int depth)
        {
            return Bitter.FromString2(
                (!)String.Format("d_{0}_{1}", depth, count)
                );
        }

        private static void CreateTree(Directory! treeRoot,
                                       int        fanout,
                                       int        depth)
        {
            if (depth <= 0) {
                return;
            }

            DebugStub.Print("CreateTree(fanout = {0}, depth = {1})",
                            __arglist(fanout, depth));

            for (int i = 0; i < fanout; i++) {
                char[]! in ExHeap nodeName = GetTreeNodeName(i, depth);
                try {
                    MSD.ErrorCode error = treeRoot.CreateDirectory(nodeName);
                    if (error != MSD.ErrorCode.NoError) {
                        DebugStub.Break();
                    }

                    Directory child;
                    error = treeRoot.OpenDirectory(nodeName, out child);
                    if (error != MSD.ErrorCode.NoError) {
                        DebugStub.Break();
                    }

                    CreateTree((!)child, fanout, depth - 1);
                }
                finally {
                    delete nodeName;
                }
            }
        }

        private static void DeleteTree(Directory! treeRoot,
                                       int fanout,
                                       int depth)
        {
            if (depth <= 0) {
                return;
            }

            DebugStub.Print("DeleteTree(fanout = {0}, depth = {1})\n",
                            __arglist(fanout, depth));

            for (int i = 0; i < fanout; i++) {
                char[]! in ExHeap nodeName = GetTreeNodeName(i, depth);
                try {
                    Directory child;
                    MSD.ErrorCode error =
                        treeRoot.OpenDirectory(nodeName, out child);
                    DebugStub.Assert(error == MSD.ErrorCode.NoError);

                    DeleteTree((!)child, fanout, depth - 1);
                    error = treeRoot.DeleteDirectory(nodeName);
                    DebugStub.Assert(error == MSD.ErrorCode.NoError);
                    error = treeRoot.OpenDirectory(nodeName, out child);
                    DebugStub.Assert(error == MSD.ErrorCode.NotFound);
                }
                finally {
                    delete nodeName;
                }
            }
        }

        private static void CreateAndDestroyTree(Directory! treeRoot,
                                                 int        fanout,
                                                 int        depth)
        {
            CreateTree(treeRoot, fanout, depth);
            DeleteTree(treeRoot, fanout, depth);
        }

        private static void CreateFile(Directory! directory,
                                       string!    filename)
        {
            File file;

            char[]! in ExHeap ename = Bitter.FromString2(filename);
            MSD.ErrorCode error = directory.CreateAndOpenFile(ename, out file);
            delete ename;
            DebugStub.Assert(error == MSD.ErrorCode.NoError);
            if (file == null) {
                return;
            }

            byte[]! in ExHeap buffer = new [ExHeap] byte [32];
            try {
                const int sections = 1000;
                for (int i = 0; i < sections; i++) {
                    byte b = (byte)('a' + (i % 26));
                    for (int j = 0; j < buffer.Length; j++) {
                        buffer[j] = b;
                    }
                    buffer[buffer.Length - 2] = (byte)'\r';
                    buffer[buffer.Length - 1] = (byte)'\n';
                    int written;
                    FileError fe = file.Write(buffer,
                                              0, (uint)(i * buffer.Length),
                                              buffer.Length, out written);
                    DebugStub.Assert(written == buffer.Length);
                    DebugStub.Assert(fe == FileError.NoError);
                }
                DebugStub.Print("Wrote {0} bytes to {1}\n",
                                __arglist(sections * buffer.Length,
                                          filename));
                file.Close();
            }
            finally {
                delete buffer;
            }
        }

        private static void CreateSparseFile(Directory! directory,
                                             string!    filename)
        {
            File file;

            char[]! in ExHeap ename = Bitter.FromString2(filename);
            MSD.ErrorCode error = directory.CreateAndOpenFile(ename, out file);
            delete ename;
            DebugStub.Assert(error == MSD.ErrorCode.NoError);
            if (file == null) {
                return;
            }

            byte[]! in ExHeap buffer = new [ExHeap] byte [32];
            try {
                const int sections = 1000;
                for (int i = 0; i < sections; i++) {
                    byte b = (byte)('a' + (i % 26));
                    for (int j = 0; j < buffer.Length; j++) {
                        buffer[j] = b;
                    }
                    buffer[buffer.Length - 2] = (byte)'\r';
                    buffer[buffer.Length - 1] = (byte)'\n';
                    int written;
                    FileError fe = file.Write(buffer,
                                              0, (uint)(2 * i * buffer.Length),
                                              buffer.Length, out written);
                    DebugStub.Assert(written == buffer.Length);
                    DebugStub.Assert(fe == FileError.NoError);
                }
                DebugStub.Print("Wrote {0} bytes to {1}\n",
                                __arglist(sections * buffer.Length,
                                          filename));
                file.Close();
            }
            finally {
                delete buffer;
            }
        }

        public static int MainTest(string []! args)
        {
            TestShortNames();

            BPB.ValidateOverlay();

            if (args.Length >= 2) {
                if (FatVolume.Mount((!)args[1], false) == false) {
                    return 0;
                }

                DateTime t0 = DateTime.Now;
                Directory! d = Directory.OpenRootDirectory();
                CreateFile(d, "testfile.txt");
                CreateSparseFile(d, "testfile2.txt");

                DateTime t1 = DateTime.Now;
                Directory! dummy = Directory.OpenRootDirectory();
                DateTime t2 = DateTime.Now;
                assert dummy != null;

                DebugStub.Print("First open took {0} ms.\n",
                                __arglist((t1 - t0).Milliseconds));
                DebugStub.Print("Second open took {0} ms.\n",
                                __arglist((t2 - t1).Milliseconds));

                //#if TEST_OPEN
                Directory foo;
                char []! in ExHeap subDirName = Bitter.FromString2("some T~1");
                d.OpenDirectory(subDirName, out foo);
                delete subDirName;

                Directory bar;
                char []! in ExHeap subDirName2 = Bitter.FromString2("foo");
                d.OpenDirectory(subDirName2, out bar);
                delete subDirName2;

                // #endif // TEST_OPEN

                EnumerateDelegate! ed1 = new EnumerateDelegate(d.Enumerate);
                DateTime t3 = DateTime.Now;
                TestEnumerate(ed1);
                DateTime t4 = DateTime.Now;
                TestEnumerate(ed1);
                DateTime t5 = DateTime.Now;

                EnumerateDelegate! ed2 = new EnumerateDelegate(d.Enumerate2);
                DateTime t6 = DateTime.Now;
                TestEnumerate(ed2);
                DateTime t7 = DateTime.Now;

                DebugStub.Print("Enum0 attempt 0 {0} ms.\n",
                                __arglist((t4 - t3).Milliseconds));
                DebugStub.Print("Enum0 attempt 1 {0} ms.\n",
                                __arglist((t5 - t4).Milliseconds));
                DebugStub.Print("Enum1 attempt 0 {0} ms.\n",
                                __arglist((t7 - t6).Milliseconds));

                EnumerateAndFindResults(d);

                const int TestFileCount = 200;
                const string TestFileBaseName = "some testing directory    ";

                DebugStub.Print("Creating test directories");
                CreateRangeOfSubDirectories(d, "Some long test dir",
                                            1, 400);

                TestEnumerate(ed1);
                TestEnumerate(ed2);
                EnumerateAndFindResults(d);

                DeleteRangeOfSubDirectories(d, "Some long test dir",
                                            1, 400);

                TestEnumerate(ed1);
                TestEnumerate(ed2);
                EnumerateAndFindResults(d);

                CreateRangeOfSubDirectories(
                    d, "The cat sat on the mat is long", 1, 3000);

                EnumerateAndFindResults(d);

                DeleteRangeOfSubDirectories(
                    d, "The cat sat on the mat is long", 1, 3000);

                TestEnumerate(ed1);
                TestEnumerate(ed2);
                EnumerateAndFindResults(d);

                CreateRangeOfSubDirectories(
                    d, "foo", 1, 300);

                EnumerateAndFindResults(d);

                DeleteRangeOfSubDirectories(
                    d, "foo", 1, 300);

                TestEnumerate(ed1);
                TestEnumerate(ed2);
                EnumerateAndFindResults(d);

                DebugStub.Print("Running directory tree create and delete test\n");
                CreateAndDestroyTree(d, 12, 3);
                FatVolume.Unmount();
            }

            return 0;
        }
    }
}