/*
 *  ReactOS kernel
 *  Copyright (C) 2002, 2004 ReactOS Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
/*
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * FILE:             services/fs/cdfs/misc.c
 * PURPOSE:          CDROM (ISO 9660) filesystem driver
 * PROGRAMMER:       Eric Kohl
 * UPDATE HISTORY:
 */

/* INCLUDES *****************************************************************/

#include "cdfs.h"

#define NDEBUG
#include <debug.h>

/* FUNCTIONS ****************************************************************/

VOID
CdfsSwapString(PWCHAR Out,
               PUCHAR In,
               ULONG Count)
{
    PUCHAR t = (PUCHAR)Out;
    ULONG i;

    for (i = 0; i < Count; i += 2)
    {
        t[i] = In[i+1];
        t[i+1] = In[i];
        if (t[i+1] == 0 && t[i] == ';')
            break;
    }
    if ((i>2)&&(t[i-2] == '.'))
    {
        t[i-2] = 0;
        t[i-1] = 0;
    }
    t[i] = 0;
    t[i+1] = 0;
}


VOID
CdfsDateTimeToSystemTime(PFCB Fcb,
                         PLARGE_INTEGER SystemTime)
{
    TIME_FIELDS TimeFields;
    LARGE_INTEGER LocalTime;

    TimeFields.Milliseconds = 0;
    TimeFields.Second = Fcb->Entry.Second;
    TimeFields.Minute = Fcb->Entry.Minute;
    TimeFields.Hour = Fcb->Entry.Hour;

    TimeFields.Day = Fcb->Entry.Day;
    TimeFields.Month = Fcb->Entry.Month;
    TimeFields.Year = Fcb->Entry.Year + 1900;

    RtlTimeFieldsToTime(&TimeFields,
        &LocalTime);
    ExLocalTimeToSystemTime(&LocalTime, SystemTime);
}


VOID
CdfsFileFlagsToAttributes(PFCB Fcb,
                          PULONG FileAttributes)
{
    /* FIXME: Fix attributes */

    *FileAttributes = // FILE_ATTRIBUTE_READONLY |
        ((Fcb->Entry.FileFlags & FILE_FLAG_HIDDEN) ? FILE_ATTRIBUTE_HIDDEN : 0) |
        ((Fcb->Entry.FileFlags & FILE_FLAG_DIRECTORY) ? FILE_ATTRIBUTE_DIRECTORY : 0) |
        ((Fcb->Entry.FileFlags & FILE_FLAG_SYSTEM) ? FILE_ATTRIBUTE_SYSTEM : 0) |
        ((Fcb->Entry.FileFlags & FILE_FLAG_READONLY) ? FILE_ATTRIBUTE_READONLY : 0);
}

BOOLEAN
CdfsIsNameLegalDOS8Dot3(IN UNICODE_STRING FileName
    )
{
    ULONG i;
    STRING DbcsName;
    CHAR DbcsNameBuffer[12];

    /* 8dot3 filename is max 12 length */
    if (FileName.Length / sizeof(WCHAR) > 12)
    {
        return FALSE;
    }

    for (i = 0; i < FileName.Length / sizeof(WCHAR) ; i++)
    {
        /* Don't allow spaces in FileName */
        if (FileName.Buffer[i] == L' ')
            return FALSE;
    }

    /* If FileName is finishing with a dot, remove it */
    if (FileName.Buffer[FileName.Length / sizeof(WCHAR) - 1] == '.')
    {
        FileName.Length -= sizeof(WCHAR);
    }

    /* Finally, convert the string to call the FsRtl function */
    DbcsName.MaximumLength = 12;
    DbcsName.Buffer = DbcsNameBuffer;
    if (!NT_SUCCESS(RtlUnicodeStringToCountedOemString(&DbcsName,
                                                       &FileName,
                                                       FALSE )))
    {

        return FALSE;
    }
    return FsRtlIsFatDbcsLegal(DbcsName, FALSE, FALSE, FALSE);
}

VOID
CdfsShortNameCacheGet
(PFCB DirectoryFcb, 
 PLARGE_INTEGER StreamOffset, 
 PUNICODE_STRING LongName, 
 PUNICODE_STRING ShortName)
{
    PLIST_ENTRY Entry;
    PCDFS_SHORT_NAME ShortNameEntry;
    GENERATE_NAME_CONTEXT Context = { 0 };

    DPRINT("CdfsShortNameCacheGet(%I64d,%wZ)\n", StreamOffset->QuadPart, LongName);

    /* Get the name list resource */
    ExAcquireResourceExclusiveLite(&DirectoryFcb->NameListResource, TRUE);

    /* Try to find the name in our cache */
    for (Entry = DirectoryFcb->ShortNameList.Flink; 
        Entry != &DirectoryFcb->ShortNameList;
        Entry = Entry->Flink)
    {
        ShortNameEntry = CONTAINING_RECORD(Entry, CDFS_SHORT_NAME, Entry);
        if (ShortNameEntry->StreamOffset.QuadPart == StreamOffset->QuadPart)
        {
            /* Cache hit */
            RtlCopyMemory
                (ShortName->Buffer, ShortNameEntry->Name.Buffer, 
                ShortNameEntry->Name.Length);
            ShortName->Length = ShortNameEntry->Name.Length;
            ExReleaseResourceLite(&DirectoryFcb->NameListResource);
            DPRINT("Yield short name %wZ from cache\n", ShortName);
            return;
        }
    }

    /* Cache miss */
    if (!CdfsIsNameLegalDOS8Dot3(*LongName))
    {
        RtlGenerate8dot3Name(LongName, FALSE, &Context, ShortName);
    }
    else
    {
        /* copy short name */
        RtlUpcaseUnicodeString
            (ShortName,
            LongName,
            FALSE);
    }

    DPRINT("Initial Guess %wZ\n", ShortName);

    /* Make it unique by scanning the cache and bumping */
    /* Note that incrementing the ambiguous name is enough, since we add new
    * entries at the tail.  We'll scan over all collisions. */
    /* XXX could perform better. */
    for (Entry = DirectoryFcb->ShortNameList.Flink; 
        Entry != &DirectoryFcb->ShortNameList;
        Entry = Entry->Flink)
    {
        ShortNameEntry = CONTAINING_RECORD(Entry, CDFS_SHORT_NAME, Entry);
        if (RtlCompareUnicodeString
            (ShortName,
            &ShortNameEntry->Name,
            TRUE) == 0) /* Match */
        {
            RtlGenerate8dot3Name(LongName, FALSE, &Context, ShortName);
            DPRINT("Collide; try %wZ\n", ShortName);
        }
    }

    /* We've scanned over all entries and now have a unique one.  Cache it. */
    ShortNameEntry = ExAllocatePoolWithTag(PagedPool, sizeof(CDFS_SHORT_NAME), TAG_FCB);
    if (!ShortNameEntry) 
    {
        /* We couldn't cache it, but we can return it.  We run the risk of
        * generating a non-unique name later. */
        ExReleaseResourceLite(&DirectoryFcb->NameListResource);
        DPRINT1("Couldn't cache potentially clashing 8.3 name %wZ\n", ShortName);
        return;
    }

    ShortNameEntry->StreamOffset = *StreamOffset;
    ShortNameEntry->Name.Buffer = ShortNameEntry->NameBuffer;
    ShortNameEntry->Name.Length = ShortName->Length;
    ShortNameEntry->Name.MaximumLength = sizeof(ShortNameEntry->NameBuffer);
    RtlCopyMemory
        (ShortNameEntry->NameBuffer, 
        ShortName->Buffer, 
        ShortName->Length);
    InsertTailList(&DirectoryFcb->ShortNameList, &ShortNameEntry->Entry);
    ExReleaseResourceLite(&DirectoryFcb->NameListResource);

    DPRINT("Returning short name %wZ for long name %wZ\n", ShortName, LongName);
}

/* EOF */
