// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "webkit/browser/fileapi/copy_or_move_operation_delegate.h"

#include "base/bind.h"
#include "base/files/file_path.h"
#include "webkit/browser/fileapi/copy_or_move_file_validator.h"
#include "webkit/browser/fileapi/file_system_context.h"
#include "webkit/browser/fileapi/file_system_operation_runner.h"
#include "webkit/browser/fileapi/file_system_url.h"
#include "webkit/browser/fileapi/recursive_operation_delegate.h"
#include "webkit/common/blob/shareable_file_reference.h"
#include "webkit/common/fileapi/file_system_util.h"

namespace fileapi {

CopyOrMoveOperationDelegate::CopyOrMoveOperationDelegate(
    FileSystemContext* file_system_context,
    const FileSystemURL& src_root,
    const FileSystemURL& dest_root,
    OperationType operation_type,
    const StatusCallback& callback)
    : RecursiveOperationDelegate(file_system_context),
      src_root_(src_root),
      dest_root_(dest_root),
      operation_type_(operation_type),
      callback_(callback),
      weak_factory_(this) {
  same_file_system_ = src_root_.IsInSameFileSystem(dest_root_);
}

CopyOrMoveOperationDelegate::~CopyOrMoveOperationDelegate() {
}

void CopyOrMoveOperationDelegate::Run() {
  // Not supported; this should never be called.
  NOTREACHED();
}

void CopyOrMoveOperationDelegate::RunRecursively() {
  // Perform light-weight checks first.

  // It is an error to try to copy/move an entry into its child.
  if (same_file_system_ && src_root_.path().IsParent(dest_root_.path())) {
    callback_.Run(base::PLATFORM_FILE_ERROR_INVALID_OPERATION);
    return;
  }

  // It is an error to copy/move an entry into the same path.
  if (same_file_system_ && src_root_.path() == dest_root_.path()) {
    callback_.Run(base::PLATFORM_FILE_ERROR_EXISTS);
    return;
  }

  // First try to copy/move it as a file.
  CopyOrMoveFile(URLPair(src_root_, dest_root_),
                 base::Bind(&CopyOrMoveOperationDelegate::DidTryCopyOrMoveFile,
                            weak_factory_.GetWeakPtr()));
}

void CopyOrMoveOperationDelegate::ProcessFile(const FileSystemURL& src_url,
                                         const StatusCallback& callback) {
  CopyOrMoveFile(URLPair(src_url, CreateDestURL(src_url)), callback);
}

void CopyOrMoveOperationDelegate::ProcessDirectory(const FileSystemURL& src_url,
                                              const StatusCallback& callback) {
  FileSystemURL dest_url = CreateDestURL(src_url);

  // If operation_type == Move we may need to record directories and
  // restore directory timestamps in the end, though it may have
  // negative performance impact.
  // See http://crbug.com/171284 for more details.
  operation_runner()->CreateDirectory(
      dest_url, false /* exclusive */, false /* recursive */, callback);
}

void CopyOrMoveOperationDelegate::DidTryCopyOrMoveFile(
    base::PlatformFileError error) {
  if (error == base::PLATFORM_FILE_OK ||
      error != base::PLATFORM_FILE_ERROR_NOT_A_FILE) {
    callback_.Run(error);
    return;
  }

  // The src_root_ looks to be a directory.
  // Try removing the dest_root_ to see if it exists and/or it is an
  // empty directory.
  operation_runner()->RemoveDirectory(
      dest_root_,
      base::Bind(&CopyOrMoveOperationDelegate::DidTryRemoveDestRoot,
                 weak_factory_.GetWeakPtr()));
}

void CopyOrMoveOperationDelegate::DidTryRemoveDestRoot(
    base::PlatformFileError error) {
  if (error == base::PLATFORM_FILE_ERROR_NOT_A_DIRECTORY) {
    callback_.Run(base::PLATFORM_FILE_ERROR_INVALID_OPERATION);
    return;
  }
  if (error != base::PLATFORM_FILE_OK &&
      error != base::PLATFORM_FILE_ERROR_NOT_FOUND) {
    callback_.Run(error);
    return;
  }

  // Start to process the source directory recursively.
  // TODO(kinuko): This could be too expensive for same_file_system_==true
  // and operation==MOVE case, probably we can just rename the root directory.
  // http://crbug.com/172187
  StartRecursiveOperation(
      src_root_,
      base::Bind(&CopyOrMoveOperationDelegate::DidFinishRecursiveCopyDir,
                 weak_factory_.GetWeakPtr(), src_root_, callback_));
}

void CopyOrMoveOperationDelegate::CopyOrMoveFile(
    const URLPair& url_pair,
    const StatusCallback& callback) {
  // Same filesystem case.
  if (same_file_system_) {
    if (operation_type_ == OPERATION_MOVE) {
      operation_runner()->MoveFileLocal(url_pair.src, url_pair.dest, callback);
    } else {
      operation_runner()->CopyFileLocal(url_pair.src, url_pair.dest, callback);
    }
    return;
  }

  // Cross filesystem case.
  // Perform CreateSnapshotFile, CopyInForeignFile and then calls
  // copy_callback which removes the source file if operation_type == MOVE.
  StatusCallback copy_callback =
      base::Bind(&CopyOrMoveOperationDelegate::DidFinishCopy,
                 weak_factory_.GetWeakPtr(), url_pair, callback);
  operation_runner()->CreateSnapshotFile(
      url_pair.src,
      base::Bind(&CopyOrMoveOperationDelegate::DidCreateSnapshot,
                 weak_factory_.GetWeakPtr(), url_pair, copy_callback));
}

void CopyOrMoveOperationDelegate::DidCreateSnapshot(
    const URLPair& url_pair,
    const StatusCallback& callback,
    base::PlatformFileError error,
    const base::PlatformFileInfo& file_info,
    const base::FilePath& platform_path,
    const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref) {
  if (error != base::PLATFORM_FILE_OK) {
    callback.Run(error);
    return;
  }
  current_file_ref_ = file_ref;

  // For now we assume CreateSnapshotFile always return a valid local file path.
  // TODO(kinuko): Otherwise create a FileStreamReader to perform a copy/move.
  DCHECK(!platform_path.empty());

  CopyOrMoveFileValidatorFactory* factory =
      file_system_context()->GetCopyOrMoveFileValidatorFactory(
          dest_root_.type(), &error);
  if (error != base::PLATFORM_FILE_OK) {
    callback.Run(error);
    return;
  }
  if (!factory) {
    DidValidateFile(url_pair.dest, callback, file_info, platform_path, error);
    return;
  }

  validator_.reset(
      factory->CreateCopyOrMoveFileValidator(url_pair.src, platform_path));
  validator_->StartPreWriteValidation(
      base::Bind(&CopyOrMoveOperationDelegate::DidValidateFile,
                 weak_factory_.GetWeakPtr(),
                 url_pair.dest, callback, file_info, platform_path));
}

void CopyOrMoveOperationDelegate::DidValidateFile(
    const FileSystemURL& dest,
    const StatusCallback& callback,
    const base::PlatformFileInfo& file_info,
    const base::FilePath& platform_path,
    base::PlatformFileError error) {
  if (error != base::PLATFORM_FILE_OK) {
    callback.Run(error);
    return;
  }

  operation_runner()->CopyInForeignFile(platform_path, dest, callback);
}

void CopyOrMoveOperationDelegate::DidFinishRecursiveCopyDir(
    const FileSystemURL& src,
    const StatusCallback& callback,
    base::PlatformFileError error) {
  if (error != base::PLATFORM_FILE_OK ||
      operation_type_ == OPERATION_COPY) {
    callback.Run(error);
    return;
  }

  DCHECK_EQ(OPERATION_MOVE, operation_type_);

  // Remove the source for finalizing move operation.
  operation_runner()->Remove(
      src, true /* recursive */,
      base::Bind(&CopyOrMoveOperationDelegate::DidRemoveSourceForMove,
                 weak_factory_.GetWeakPtr(), callback));
}

void CopyOrMoveOperationDelegate::DidFinishCopy(
    const URLPair& url_pair,
    const StatusCallback& callback,
    base::PlatformFileError error) {
  if (error != base::PLATFORM_FILE_OK) {
    callback.Run(error);
    return;
  }

  // |validator_| is NULL in the same-filesystem case or when the destination
  // filesystem does not do validation.
  if (!validator_.get()) {
    scoped_refptr<webkit_blob::ShareableFileReference> file_ref;
    DidPostWriteValidation(url_pair, callback, file_ref,
                           base::PLATFORM_FILE_OK);
    return;
  }

  DCHECK(!same_file_system_);
  operation_runner()->CreateSnapshotFile(
      url_pair.dest,
      base::Bind(&CopyOrMoveOperationDelegate::DoPostWriteValidation,
                 weak_factory_.GetWeakPtr(), url_pair, callback));
}

void CopyOrMoveOperationDelegate::DoPostWriteValidation(
    const URLPair& url_pair,
    const StatusCallback& callback,
    base::PlatformFileError error,
    const base::PlatformFileInfo& file_info,
    const base::FilePath& platform_path,
    const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref) {
  if (error != base::PLATFORM_FILE_OK) {
    operation_runner()->Remove(
        url_pair.dest, true,
        base::Bind(&CopyOrMoveOperationDelegate::DidRemoveDestForError,
                   weak_factory_.GetWeakPtr(), error, callback));
    return;
  }

  DCHECK(validator_.get());
  // Note: file_ref passed here to keep the file alive until after
  // the StartPostWriteValidation operation finishes.
  validator_->StartPostWriteValidation(
      platform_path,
      base::Bind(&CopyOrMoveOperationDelegate::DidPostWriteValidation,
                 weak_factory_.GetWeakPtr(), url_pair, callback, file_ref));
}

// |file_ref| is unused; it is passed here to make sure the reference is
// alive until after post-write validation is complete.
void CopyOrMoveOperationDelegate::DidPostWriteValidation(
    const URLPair& url_pair,
    const StatusCallback& callback,
    const scoped_refptr<webkit_blob::ShareableFileReference>& /*file_ref*/,
    base::PlatformFileError error) {
  if (error != base::PLATFORM_FILE_OK) {
    operation_runner()->Remove(
        url_pair.dest, true,
        base::Bind(&CopyOrMoveOperationDelegate::DidRemoveDestForError,
                   weak_factory_.GetWeakPtr(), error, callback));
    return;
  }

  if (operation_type_ == OPERATION_COPY) {
    callback.Run(error);
    return;
  }

  DCHECK_EQ(OPERATION_MOVE, operation_type_);

  // Remove the source for finalizing move operation.
  operation_runner()->Remove(
      url_pair.src, true /* recursive */,
      base::Bind(&CopyOrMoveOperationDelegate::DidRemoveSourceForMove,
                 weak_factory_.GetWeakPtr(), callback));
}

void CopyOrMoveOperationDelegate::DidRemoveSourceForMove(
    const StatusCallback& callback,
    base::PlatformFileError error) {
  if (error == base::PLATFORM_FILE_ERROR_NOT_FOUND)
    error = base::PLATFORM_FILE_OK;
  callback.Run(error);
}

FileSystemURL CopyOrMoveOperationDelegate::CreateDestURL(
    const FileSystemURL& src_url) const {
  DCHECK_EQ(src_root_.type(), src_url.type());
  DCHECK_EQ(src_root_.origin(), src_url.origin());

  base::FilePath relative = dest_root_.virtual_path();
  src_root_.virtual_path().AppendRelativePath(src_url.virtual_path(),
                                              &relative);
  return file_system_context()->CreateCrackedFileSystemURL(
      dest_root_.origin(),
      dest_root_.mount_type(),
      relative);
}

void CopyOrMoveOperationDelegate::DidRemoveDestForError(
    base::PlatformFileError prior_error,
    const StatusCallback& callback,
    base::PlatformFileError error) {
  if (error != base::PLATFORM_FILE_OK) {
    VLOG(1) << "Error removing destination file after validation error: "
            << error;
  }
  callback.Run(prior_error);
}

}  // namespace fileapi