/* $Id: create.c,v 1.2 2000/01/12 19:05:32 ekohl Exp $
 *
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * FILE:             services/fs/vfat/create.c
 * PURPOSE:          VFAT Filesystem
 * PROGRAMMER:       Jason Filby (jasonfilby@yahoo.com)

 */

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

#include <wchar.h>
#include <internal/string.h>
#include <ddk/ntddk.h>
#include <ddk/cctypes.h>

#define NDEBUG
#include <internal/debug.h>

#include "vfat.h"

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

BOOLEAN IsLastEntry(PVOID Block, ULONG Offset)
/*
 * FUNCTION: Determine if the given directory entry is the last
 */
{
   return(((FATDirEntry *)Block)[Offset].Filename[0] == 0);
}

BOOLEAN IsVolEntry(PVOID Block, ULONG Offset)
/*
 * FUNCTION: Determine if the given directory entry is a vol entry
 */
{
   if( (((FATDirEntry *)Block)[Offset].Attrib)==0x28 ) return TRUE;
   else return FALSE;
}

BOOLEAN IsDeletedEntry(PVOID Block, ULONG Offset)
/*
 * FUNCTION: Determines if the given entry is a deleted one
 */
{
   /* Checks special character */

   return ((((FATDirEntry *)Block)[Offset].Filename[0] == 0xe5));
}

BOOLEAN GetEntryName(PVOID Block, PULONG _Offset, PWSTR Name, PULONG _jloop,
  PDEVICE_EXTENSION DeviceExt, ULONG * _StartingSector)
/*
 * FUNCTION: Retrieves the file name, be it in short or long file name format
 */
{
   FATDirEntry* test;
   slot* test2;
   ULONG Offset = *_Offset;
   ULONG StartingSector = *_StartingSector;
   ULONG jloop = *_jloop;
   ULONG cpos;
   
   test = (FATDirEntry *)Block;
   test2 = (slot *)Block;
   
   *Name = 0;

   if (IsDeletedEntry(Block,Offset))
     {
	return(FALSE);
     }
   
   if(test2[Offset].attr == 0x0f) 
     {
        vfat_initstr(Name, 256);
	vfat_wcsncpy(Name,test2[Offset].name0_4,5);
	vfat_wcsncat(Name,test2[Offset].name5_10,5,6);
	vfat_wcsncat(Name,test2[Offset].name11_12,11,2);

        cpos=0;
        while((test2[Offset].id!=0x41) && (test2[Offset].id!=0x01) &&
	      (test2[Offset].attr>0)) 
	  {
	     Offset++;
             if(Offset==ENTRIES_PER_SECTOR) {
               Offset=0;
               StartingSector++;//FIXME : nor always the next sector
               jloop++;
               VFATReadSectors(DeviceExt->StorageDevice,StartingSector,1,Block);
               test2 = (slot *)Block;
             }
             cpos++;
             vfat_movstr(Name, 13, 0, cpos*13);
             vfat_wcsncpy(Name, test2[Offset].name0_4, 5);
             vfat_wcsncat(Name,test2[Offset].name5_10,5,6);
             vfat_wcsncat(Name,test2[Offset].name11_12,11,2);

          }

	if (IsDeletedEntry(Block,Offset+1))
	  {
	     Offset++;
	     *_Offset = Offset;
             *_jloop = jloop;
             *_StartingSector = StartingSector;
	     return(FALSE);
	  }
	
	*_Offset = Offset;
        *_jloop = jloop;
        *_StartingSector = StartingSector;
	
	return(TRUE);
     }   
      
   RtlAnsiToUnicode(Name,test[Offset].Filename,8);
   if (test[Offset].Ext[0]!=' ')
     {
	RtlCatAnsiToUnicode(Name,".",1);
     }
   RtlCatAnsiToUnicode(Name,test[Offset].Ext,3);
      
   *_Offset = Offset;
   
   return(TRUE);
}

NTSTATUS ReadVolumeLabel(PDEVICE_EXTENSION DeviceExt, PVPB Vpb)
/*
 * FUNCTION: Read the volume label
 */
{
   ULONG i = 0;
   ULONG j;
   ULONG Size;
   char* block;
   ULONG StartingSector;
   ULONG NextCluster;

   Size = DeviceExt->rootDirectorySectors;//FIXME : in fat32, no limit
   StartingSector = DeviceExt->rootStart;
   NextCluster=0;

   block = ExAllocatePool(NonPagedPool,BLOCKSIZE);
   DPRINT("FindFile : start at sector %lx, entry %ld\n",StartingSector,i);
   for (j=0; j<Size; j++)
   {
     VFATReadSectors(DeviceExt->StorageDevice,StartingSector,1,block);

     for (i=0; i<ENTRIES_PER_SECTOR; i++)
     {
       if (IsVolEntry((PVOID)block,i))
       {
         FATDirEntry *test = (FATDirEntry *)block;

         /* copy volume label */
         RtlAnsiToUnicode(Vpb->VolumeLabel,test[i].Filename,8);
         RtlCatAnsiToUnicode(Vpb->VolumeLabel,test[i].Ext,3);
         Vpb->VolumeLabelLength = wcslen(Vpb->VolumeLabel);

         ExFreePool(block);
         return(STATUS_SUCCESS);
       }
       if (IsLastEntry((PVOID)block,i))
       {
         *(Vpb->VolumeLabel) = 0;
         Vpb->VolumeLabelLength = 0;
         ExFreePool(block);
         return(STATUS_UNSUCCESSFUL);
       }
     }
     // not found in this sector, try next :

     /* directory can be fragmented although it is best to keep them
        unfragmented */
     StartingSector++;
     if (DeviceExt->FatType ==FAT32)
     {
       if(StartingSector==ClusterToSector(DeviceExt,NextCluster+1))
       {
         NextCluster = GetNextCluster(DeviceExt,NextCluster);
         if (NextCluster == 0||NextCluster==0xffffffff)
         {
           *(Vpb->VolumeLabel) = 0;
           Vpb->VolumeLabelLength = 0;
           ExFreePool(block);
           return(STATUS_UNSUCCESSFUL);
         }
         StartingSector = ClusterToSector(DeviceExt,NextCluster);
       }
     }
   }
   *(Vpb->VolumeLabel) = 0;
   Vpb->VolumeLabelLength = 0;
   ExFreePool(block);
   return(STATUS_UNSUCCESSFUL);
}


NTSTATUS FindFile(PDEVICE_EXTENSION DeviceExt, PVFATFCB Fcb,
          PVFATFCB Parent, PWSTR FileToFind,ULONG *StartSector,ULONG *Entry)
/*
 * FUNCTION: Find a file
 */
{
   ULONG i, j;
   ULONG Size;
   char* block;
   WCHAR name[256];
   ULONG StartingSector;
   ULONG NextCluster;
   WCHAR TempStr[2];
   
   DPRINT("FindFile(Parent %x, FileToFind '%S')\n",Parent,FileToFind);
   
   if (wcslen(FileToFind)==0)
     {
	CHECKPOINT;
        TempStr[0] = (WCHAR)'.';
	TempStr[1] = 0;
	FileToFind=(PWSTR)&TempStr;
     }
   if (Parent != NULL)
     {
	DPRINT("Parent->entry.FirstCluster %d\n",Parent->entry.FirstCluster);
     }
   
   DPRINT("FindFile '%S'\n", FileToFind);
   if (Parent == NULL||Parent->entry.FirstCluster==1)
     {
	CHECKPOINT;
	Size = DeviceExt->rootDirectorySectors; /* FIXME : in fat32, no limit */
	StartingSector = DeviceExt->rootStart;
	NextCluster=0;
	if(FileToFind[0]==0 ||(FileToFind[0]=='\\' && FileToFind[1]==0) ||
	   (FileToFind[0]=='.' && FileToFind[1]==0))
	  {
	     /* it's root : complete essentials fields then return ok */
	     CHECKPOINT;
	     memset(Fcb,0,sizeof(VFATFCB));
	     memset(Fcb->entry.Filename,' ',11);
	     Fcb->entry.FileSize=DeviceExt->rootDirectorySectors*BLOCKSIZE;
	     Fcb->entry.Attrib=FILE_ATTRIBUTE_DIRECTORY;
	     if (DeviceExt->FatType == FAT32)
	       Fcb->entry.FirstCluster=2;
	     else
	       Fcb->entry.FirstCluster=1; /* FIXME : is 1 the good value for mark root? */
	     if(StartSector)
	       *StartSector=StartingSector;
	     if(Entry)
	       *Entry=0;
	     return(STATUS_SUCCESS);
	  }
     }
   else
     {
	DPRINT("Parent->entry.FileSize %x\n",Parent->entry.FileSize);
	
	Size = ULONG_MAX;
	if (DeviceExt->FatType == FAT32)
	  NextCluster = Parent->entry.FirstCluster
	  +Parent->entry.FirstClusterHigh*65536;
	else
	  NextCluster = Parent->entry.FirstCluster;
	StartingSector = ClusterToSector(DeviceExt, NextCluster);
	if(Parent->entry.FirstCluster==1 && DeviceExt->FatType!=FAT32)
	  {
	     /* read of root directory in FAT16 or FAT12 */
	     StartingSector=DeviceExt->rootStart;
	  }
     }
   CHECKPOINT;
   block = ExAllocatePool(NonPagedPool,BLOCKSIZE);
   CHECKPOINT;
   if (StartSector && (*StartSector)) StartingSector=*StartSector;
   i=(Entry)?(*Entry):0;
   DPRINT("FindFile : start at sector %lx, entry %ld\n",StartingSector,i);
   for (j=0; j<Size; j++)
     {
	VFATReadSectors(DeviceExt->StorageDevice,StartingSector,1,block);
	
	for (i=(Entry)?(*Entry):0; i<ENTRIES_PER_SECTOR; i++)
	  {
	     if (IsVolEntry((PVOID)block,i))
	       continue;
	     if (IsLastEntry((PVOID)block,i))
	       {
		  if(StartSector) *StartSector=StartingSector;
		  if(Entry) *Entry=i;
		  ExFreePool(block);
		  return(STATUS_UNSUCCESSFUL);
	       }
	     if (GetEntryName((PVOID)block,&i,name,&j,DeviceExt,&StartingSector))
	       {
		  DPRINT("Comparing '%S' '%S'\n",name,FileToFind);
		  if (wstrcmpjoki(name,FileToFind))
		    {
		       /* In the case of a long filename, the firstcluster is stored in
			the next record -- where it's short name is */
		       if(((FATDirEntry *)block)[i].Attrib==0x0f) i++;
		       if( i==(ENTRIES_PER_SECTOR))
			 {
			    /* entry is in next sector */
			    StartingSector++;
			    /* FIXME : treat case of next sector fragmented */
			    VFATReadSectors(DeviceExt->StorageDevice,StartingSector,1,block);
			    i=0;
			 }
		       memcpy(&Fcb->entry,&((FATDirEntry *)block)[i],
			      sizeof(FATDirEntry));
		       vfat_wcsncpy(Fcb->ObjectName,name,MAX_PATH);
		       if(StartSector) *StartSector=StartingSector;
		       if(Entry) *Entry=i;
		       ExFreePool(block);
		       return(STATUS_SUCCESS);
		    }
	       }
	  }
	/* not found in this sector, try next : */
	
	/* directory can be fragmented although it is best to keep them
	 unfragmented */
	if(Entry) *Entry=0;
	StartingSector++;
	if ((Parent != NULL && Parent->entry.FirstCluster!=1)
	    || DeviceExt->FatType ==FAT32)
	  {
	     if(StartingSector==ClusterToSector(DeviceExt,NextCluster+1))
	       {
		  NextCluster = GetNextCluster(DeviceExt,NextCluster);
		  if (NextCluster == 0||NextCluster==0xffffffff)
		    {
		       if(StartSector) *StartSector=StartingSector;
		       if(Entry) *Entry=i;
		       ExFreePool(block);
		       return(STATUS_UNSUCCESSFUL);
		    }
		  StartingSector = ClusterToSector(DeviceExt,NextCluster);
	       }
	  }
     }
   if(StartSector) *StartSector=StartingSector;
   if(Entry) *Entry=i;
   ExFreePool(block);
   return(STATUS_UNSUCCESSFUL);
}


NTSTATUS FsdCloseFile(PDEVICE_EXTENSION DeviceExt, PFILE_OBJECT FileObject)
/*
 * FUNCTION: Closes a file
 */
{
   PVFATFCB pFcb;
   PVFATCCB pCcb;
   KIRQL oldIrql;
   
   DPRINT("FsdCloseFile(DeviceExt %x, FileObject %x)\n",
	  DeviceExt,FileObject);
   
 //FIXME : update entry in directory ?
   pCcb = (PVFATCCB)(FileObject->FsContext2);
   
   DPRINT("pCcb %x\n",pCcb);
   if (pCcb == NULL)
     {
	return(STATUS_SUCCESS);
     }
   
   pFcb = pCcb->pFcb;
   
   pFcb->RefCount--;
   if(pFcb->RefCount<=0)
   {
      KeAcquireSpinLock(&DeviceExt->FcbListLock, &oldIrql);
      RemoveEntryList(&pFcb->FcbListEntry);
      KeReleaseSpinLock(&DeviceExt->FcbListLock, oldIrql);
      ExFreePool(pFcb);
   }
   ExFreePool(pCcb);
   return STATUS_SUCCESS;
}

NTSTATUS FsdOpenFile(PDEVICE_EXTENSION DeviceExt, PFILE_OBJECT FileObject, 
		     PWSTR FileName)
/*
 * FUNCTION: Opens a file
 */
{
   PWSTR current = NULL;
   PWSTR next;
   PWSTR string;
   PVFATFCB ParentFcb;
   PVFATFCB Fcb,pRelFcb;
   PVFATFCB Temp;
 PVFATCCB newCCB,pRelCcb;
   NTSTATUS Status;
   PFILE_OBJECT pRelFileObject;
   PWSTR AbsFileName=NULL;
   short i,j;
   PLIST_ENTRY current_entry;
   KIRQL oldIrql;
   
   DPRINT("FsdOpenFile(%08lx, %08lx, %S)\n", 
          DeviceExt,
          FileObject,
          FileName);
   
  /* FIXME : treat relative name */
   if(FileObject->RelatedFileObject)
   {
      DbgPrint("try related for %S\n",FileName);
     pRelFileObject=FileObject->RelatedFileObject;
     pRelCcb=pRelFileObject->FsContext2;
     assert(pRelCcb);
     pRelFcb=pRelCcb->pFcb;
     assert(pRelFcb);
     /*
      * verify related object is a directory and target name don't start with \.
      */
     if( !(pRelFcb->entry.Attrib & FILE_ATTRIBUTE_DIRECTORY)
         || (FileName[0]!= '\\') )
     {
       Status=STATUS_INVALID_PARAMETER;
       return Status;
     }
     /* construct absolute path name */
     AbsFileName=ExAllocatePool(NonPagedPool,MAX_PATH);
     for (i=0;pRelFcb->PathName[i];i++)
       AbsFileName[i]=pRelFcb->PathName[i];
     AbsFileName[i++]='\\';
     for (j=0;FileName[j]&&i<MAX_PATH;j++)
       AbsFileName[i++]=FileName[j];
     assert(i<MAX_PATH);
     AbsFileName[i]=0;
     FileName=AbsFileName;
   }
 
 /*
  * try first to find an existing FCB in memory
  */
   CHECKPOINT;
   
   KeAcquireSpinLock(&DeviceExt->FcbListLock, &oldIrql);
   current_entry = DeviceExt->FcbListHead.Flink;
   while (current_entry != &DeviceExt->FcbListHead)
     {
	Fcb = CONTAINING_RECORD(current_entry, VFATFCB, FcbListEntry);

	DPRINT("Scanning %x\n", Fcb);
	DPRINT("Scanning %S\n", Fcb->PathName);
	
	if (DeviceExt==Fcb->pDevExt
	    && wstrcmpi(FileName,Fcb->PathName))
	  {
	     Fcb->RefCount++;
	     KeReleaseSpinLock(&DeviceExt->FcbListLock, oldIrql);
	     FileObject->FsContext =(PVOID) &Fcb->NTRequiredFCB;
	     newCCB = ExAllocatePool(NonPagedPool,sizeof(VFATCCB));
	     memset(newCCB,0,sizeof(VFATCCB));
	     FileObject->FsContext2 = newCCB;
	     newCCB->pFcb=Fcb;
	     newCCB->PtrFileObject=FileObject;
	     if(AbsFileName)ExFreePool(AbsFileName);
	     return(STATUS_SUCCESS);
	  }
	
	current_entry = current_entry->Flink;
     }
   KeReleaseSpinLock(&DeviceExt->FcbListLock, oldIrql);
   
 CHECKPOINT; 

 string = FileName;
 ParentFcb = NULL;
 Fcb = ExAllocatePool(NonPagedPool, sizeof(VFATFCB));
 memset(Fcb,0,sizeof(VFATFCB));
 Fcb->ObjectName=Fcb->PathName;
 next = &string[0];   
   
   CHECKPOINT;
   while (next!=NULL)
   {
      CHECKPOINT;
     *next = '\\';
     current = next+1;
     next = wcschr(next+1,'\\');
     if (next!=NULL)
	{
	   *next=0;
	}
      DPRINT("current '%S'\n",current);
      Status = FindFile(DeviceExt,Fcb,ParentFcb,current,NULL,NULL);
      if (Status != STATUS_SUCCESS)
	{
	   CHECKPOINT;
	   if (Fcb != NULL)
	     ExFreePool(Fcb);
	   if (ParentFcb != NULL)
	     ExFreePool(ParentFcb);
	   if(AbsFileName)
             ExFreePool(AbsFileName);
           return(Status);
	}
      Temp = Fcb;
CHECKPOINT;
      if (ParentFcb == NULL)
	{
	   CHECKPOINT;
	   Fcb = ExAllocatePool(NonPagedPool,sizeof(VFATFCB));
	   memset(Fcb,0,sizeof(VFATFCB));
	   Fcb->ObjectName=Fcb->PathName;
	}
      else
        Fcb = ParentFcb;
CHECKPOINT;
      ParentFcb = Temp;
   }
CHECKPOINT;
 FileObject->FsContext =(PVOID) &ParentFcb->NTRequiredFCB;
   newCCB = ExAllocatePool(NonPagedPool,sizeof(VFATCCB));
   memset(newCCB,0,sizeof(VFATCCB));
   FileObject->FsContext2 = newCCB;
   newCCB->pFcb=ParentFcb;
   newCCB->PtrFileObject=FileObject;
   ParentFcb->RefCount++;
   //FIXME : initialize all fields in FCB and CCB
   
   KeAcquireSpinLock(&DeviceExt->FcbListLock, &oldIrql);
   InsertTailList(&DeviceExt->FcbListHead, &ParentFcb->FcbListEntry);
   KeReleaseSpinLock(&DeviceExt->FcbListLock, oldIrql);
   
   vfat_wcsncpy(ParentFcb->PathName,FileName,MAX_PATH);
   ParentFcb->ObjectName=ParentFcb->PathName+(current-FileName);
   ParentFcb->pDevExt=DeviceExt;
   DPRINT("file open, fcb=%x\n",ParentFcb);
   DPRINT("FileSize %d\n",ParentFcb->entry.FileSize);
   if(Fcb) ExFreePool(Fcb);
   if(AbsFileName)ExFreePool(AbsFileName);
   CHECKPOINT;
   return(STATUS_SUCCESS);
 }
 
NTSTATUS FsdClose(PDEVICE_OBJECT DeviceObject, PIRP Irp)
/*
 * FUNCTION: Close a file
 */
{
   PIO_STACK_LOCATION Stack = IoGetCurrentIrpStackLocation(Irp);
   PFILE_OBJECT FileObject = Stack->FileObject;
   PDEVICE_EXTENSION DeviceExtension = DeviceObject->DeviceExtension;
   NTSTATUS Status;

   DPRINT("FsdClose(DeviceObject %x, Irp %x)\n",DeviceObject, Irp);
   
   Status = FsdCloseFile(DeviceExtension,FileObject);

   Irp->IoStatus.Status = Status;
   Irp->IoStatus.Information = 0;
   
   IoCompleteRequest(Irp, IO_NO_INCREMENT);
   return(Status);
}


NTSTATUS FsdCreate(PDEVICE_OBJECT DeviceObject, PIRP Irp)
/*
 * FUNCTION: Create or open a file
 */
{
   PIO_STACK_LOCATION Stack;
   PFILE_OBJECT FileObject;
   NTSTATUS Status=STATUS_SUCCESS;
   PDEVICE_EXTENSION DeviceExt;
   ULONG RequestedDisposition,RequestedOptions;
   PVFATCCB pCcb;
   PVFATFCB pFcb;

   assert(DeviceObject);
   assert(Irp);
   
   if (DeviceObject->Size==sizeof(DEVICE_OBJECT))
   {
      /* DeviceObject represent FileSystem instead of  logical volume */
      DbgPrint("FsdCreate called with file system\n");
      Irp->IoStatus.Status=Status;
      Irp->IoStatus.Information=FILE_OPENED;
      IoCompleteRequest(Irp,IO_NO_INCREMENT);
      return(Status);
   }
   
   Stack = IoGetCurrentIrpStackLocation(Irp);
   assert(Stack);
   RequestedDisposition = ((Stack->Parameters.Create.Options>>24)&0xff);
   RequestedOptions=Stack->Parameters.Create.Options&FILE_VALID_OPTION_FLAGS;
   FileObject = Stack->FileObject;
   DeviceExt = DeviceObject->DeviceExtension;
   assert(DeviceExt);
   ExAcquireResourceExclusiveLite(&DeviceExt->DirResource, TRUE);
   Status = FsdOpenFile(DeviceExt,FileObject,FileObject->FileName.Buffer);
   CHECKPOINT;
   Irp->IoStatus.Information = 0;
   if(!NT_SUCCESS(Status))
     {
      if(RequestedDisposition==FILE_CREATE
         ||RequestedDisposition==FILE_OPEN_IF
         ||RequestedDisposition==FILE_OVERWRITE_IF)
      {
CHECKPOINT;
         Status=addEntry(DeviceExt,FileObject,RequestedOptions
             ,(Stack->Parameters.Create.FileAttributes & FILE_ATTRIBUTE_VALID_FLAGS));
         if(NT_SUCCESS(Status))
           Irp->IoStatus.Information = FILE_CREATED;
         // FIXME set size if AllocationSize requested
         // FIXME set extended attributes ?
         // FIXME set share access
         // IoSetShareAccess(DesiredAccess,ShareAccess,FileObject
         //   ,((PVfatCCB)(FileObject->FsContext2))->pFcb->FCBShareAccess);
      }
   }
   else
   {
     if(RequestedDisposition==FILE_CREATE)
     {
       Irp->IoStatus.Information = FILE_EXISTS;
       Status=STATUS_OBJECT_NAME_COLLISION;
     }
     pCcb=FileObject->FsContext2;
     pFcb=pCcb->pFcb;
     if( (RequestedOptions&FILE_NON_DIRECTORY_FILE)
         && (pFcb->entry.Attrib & FILE_ATTRIBUTE_DIRECTORY))
     {
       Status=STATUS_FILE_IS_A_DIRECTORY;
     }
     if( (RequestedOptions&FILE_DIRECTORY_FILE)
         && !(pFcb->entry.Attrib & FILE_ATTRIBUTE_DIRECTORY))
     {
       Status=STATUS_NOT_A_DIRECTORY;
     }
     // FIXME : test share access
     // FIXME : test write access if requested
     if(!NT_SUCCESS(Status))
       FsdCloseFile(DeviceExt,FileObject);
     else Irp->IoStatus.Information = FILE_OPENED;
     // FIXME : make supersed or overwrite if requested
   }
CHECKPOINT;   
   
   Irp->IoStatus.Status = Status;   
   IoCompleteRequest(Irp, IO_NO_INCREMENT);
   ExReleaseResourceLite(&DeviceExt->DirResource);
   
   return Status;
}