/** @file

;******************************************************************************
;* Copyright (c) 2020, Insyde Software Corp. All Rights Reserved.
;*
;* You may not reproduce, distribute, publish, display, perform, modify, adapt,
;* transmit, broadcast, present, recite, release, license or otherwise exploit
;* any part of this publication in any form, by any means, without the prior
;* written permission of Insyde Software Corporation.
;*
;******************************************************************************
*/

/** @file
  Internal file explorer helper functions for RamDiskDxe driver.

  Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include "RamDiskImpl.h"


/**
  Helper function called as part of the code needed to allocate the proper
  sized buffer for various EFI interfaces.

  @param[in, out] Status     Current status.
  @param[in, out] Buffer     Current allocated buffer, or NULL.
  @param[in]      BufferSize Current buffer size needed.

  @retval  TRUE         If the buffer was reallocated and the caller should
                        try the API again.
  @retval  FALSE        The caller should not call this function again.

**/
BOOLEAN
GrowBuffer (
  IN OUT EFI_STATUS   *Status,
  IN OUT VOID         **Buffer,
  IN UINTN            BufferSize
  )
{
  BOOLEAN TryAgain;

  //
  // If this is an initial request, buffer will be null with a new buffer size
  //
  if ((*Buffer == NULL) && (BufferSize != 0)) {
    *Status = EFI_BUFFER_TOO_SMALL;
  }
  //
  // If the status code is "buffer too small", resize the buffer
  //
  TryAgain = FALSE;
  if (*Status == EFI_BUFFER_TOO_SMALL) {

    if (*Buffer != NULL) {
      FreePool (*Buffer);
    }

    *Buffer = AllocateZeroPool (BufferSize);

    if (*Buffer != NULL) {
      TryAgain = TRUE;
    } else {
      *Status = EFI_OUT_OF_RESOURCES;
    }
  }
  //
  // If there's an error, free the buffer
  //
  if (!TryAgain && EFI_ERROR (*Status) && (*Buffer != NULL)) {
    FreePool (*Buffer);
    *Buffer = NULL;
  }

  return TryAgain;
}


/**
  This function gets the file information from an open file descriptor,
  and stores it in a buffer allocated from pool.

  @param[in] FHand           File Handle.

  @return    A pointer to a buffer with file information or NULL is returned.

**/
EFI_FILE_INFO *
FileInfo (
  IN EFI_FILE_HANDLE                        FHand
  )
{
  EFI_STATUS                           Status;
  EFI_FILE_INFO                        *Buffer;
  UINTN                                BufferSize;

  //
  // Initialize for GrowBuffer loop
  //
  Buffer      = NULL;
  BufferSize  = SIZE_OF_EFI_FILE_INFO + 200;

  //
  // Call the real function
  //
  while (GrowBuffer (&Status, (VOID **) &Buffer, BufferSize)) {
    Status = FHand->GetInfo (
                      FHand,
                      &gEfiFileInfoGuid,
                      &BufferSize,
                      Buffer
                      );
  }

  return Buffer;
}


/**
  This function will open a file or directory referenced by DevicePath.

  This function opens a file with the open mode according to the file path. The
  Attributes is valid only for EFI_FILE_MODE_CREATE.

  @param[in, out] FilePath   On input, the device path to the file.
                             On output, the remaining device path.
  @param[out]     FileHandle Pointer to the file handle.
  @param[in]      OpenMode   The mode to open the file with.
  @param[in]      Attributes The file's file attributes.

  @retval EFI_SUCCESS             The information was set.
  @retval EFI_INVALID_PARAMETER   One of the parameters has an invalid value.
  @retval EFI_UNSUPPORTED         Could not open the file path.
  @retval EFI_NOT_FOUND           The specified file could not be found on the
                                  device or the file system could not be found
                                  on the device.
  @retval EFI_NO_MEDIA            The device has no medium.
  @retval EFI_MEDIA_CHANGED       The device has a different medium in it or
                                  the medium is no longer supported.
  @retval EFI_DEVICE_ERROR        The device reported an error.
  @retval EFI_VOLUME_CORRUPTED    The file system structures are corrupted.
  @retval EFI_WRITE_PROTECTED     The file or medium is write protected.
  @retval EFI_ACCESS_DENIED       The file was opened read only.
  @retval EFI_OUT_OF_RESOURCES    Not enough resources were available to open
                                  the file.
  @retval EFI_VOLUME_FULL         The volume is full.
**/
EFI_STATUS
EFIAPI
OpenFileByDevicePath(
  IN OUT EFI_DEVICE_PATH_PROTOCOL           **FilePath,
  OUT EFI_FILE_HANDLE                       *FileHandle,
  IN UINT64                                 OpenMode,
  IN UINT64                                 Attributes
  )
{
  EFI_STATUS                           Status;
  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL      *EfiSimpleFileSystemProtocol;
  EFI_FILE_PROTOCOL                    *Handle1;
  EFI_FILE_PROTOCOL                    *Handle2;
  EFI_HANDLE                           DeviceHandle;

  if ((FilePath == NULL || FileHandle == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  Status = gBS->LocateDevicePath (
                  &gEfiSimpleFileSystemProtocolGuid,
                  FilePath,
                  &DeviceHandle
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  Status = gBS->OpenProtocol(
                  DeviceHandle,
                  &gEfiSimpleFileSystemProtocolGuid,
                  (VOID**)&EfiSimpleFileSystemProtocol,
                  gImageHandle,
                  NULL,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  Status = EfiSimpleFileSystemProtocol->OpenVolume(EfiSimpleFileSystemProtocol, &Handle1);
  if (EFI_ERROR (Status)) {
    FileHandle = NULL;
    return Status;
  }

  //
  // go down directories one node at a time.
  //
  while (!IsDevicePathEnd (*FilePath)) {
    //
    // For file system access each node should be a file path component
    //
    if (DevicePathType    (*FilePath) != MEDIA_DEVICE_PATH ||
        DevicePathSubType (*FilePath) != MEDIA_FILEPATH_DP
       ) {
      FileHandle = NULL;
      return (EFI_INVALID_PARAMETER);
    }
    //
    // Open this file path node
    //
    Handle2  = Handle1;
    Handle1 = NULL;

    //
    // Try to test opening an existing file
    //
    Status = Handle2->Open (
                          Handle2,
                          &Handle1,
                          ((FILEPATH_DEVICE_PATH*)*FilePath)->PathName,
                          OpenMode &~EFI_FILE_MODE_CREATE,
                          0
                         );

    //
    // see if the error was that it needs to be created
    //
    if ((EFI_ERROR (Status)) && (OpenMode != (OpenMode &~EFI_FILE_MODE_CREATE))) {
      Status = Handle2->Open (
                            Handle2,
                            &Handle1,
                            ((FILEPATH_DEVICE_PATH*)*FilePath)->PathName,
                            OpenMode,
                            Attributes
                           );
    }
    //
    // Close the last node
    //
    Handle2->Close (Handle2);

    if (EFI_ERROR(Status)) {
      return (Status);
    }

    //
    // Get the next node
    //
    *FilePath = NextDevicePathNode (*FilePath);
  }

  //
  // This is a weak spot since if the undefined SHELL_FILE_HANDLE format changes this must change also!
  //
  *FileHandle = (VOID*)Handle1;
  return EFI_SUCCESS;
}