// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SRC_BRINGUP_BIN_NETSVC_FILE_API_H_
#define SRC_BRINGUP_BIN_NETSVC_FILE_API_H_

#include <zircon/boot/netboot.h>

#include <tftp/tftp.h>

#include "netcp.h"
#include "paver.h"

namespace netsvc {

// Provides capabilities to read/write files sent over TFTP.
//
// Reads only implements netcp. Specifically it enables reading of files in
// global /data.
//
// Writes come in 4 flavors:
// * netcp: Ability to write to global /data.
// * netboot: Mexec into image once write completes.
// * paving: Writes boot partions, or FVM.
// * board name validation: Validates that board name sent matches current
//   board.
class FileApiInterface {
 public:
  // Returns size of file on success.
  virtual ssize_t OpenRead(const char* filename) = 0;
  virtual tftp_status OpenWrite(const char* filename, size_t size) = 0;
  virtual tftp_status Read(void* data, size_t* length, off_t offset) = 0;
  virtual tftp_status Write(const void* data, size_t* length, off_t offset) = 0;
  virtual void Close() = 0;
  // Like close, but signals read or write operation was incomplete.
  virtual void Abort() = 0;

  virtual bool is_write() = 0;
  virtual const char* filename() = 0;
};

class FileApi : public FileApiInterface {
 public:
  // FileApi does *not* take ownership of |paver|.
  explicit FileApi(bool is_zedboot,
                   std::unique_ptr<NetCopyInterface> netcp = std::make_unique<NetCopy>(),
                   zx::channel sysinfo = zx::channel(), PaverInterface* paver = Paver::Get());

  ssize_t OpenRead(const char* filename) final;
  tftp_status OpenWrite(const char* filename, size_t size) final;
  tftp_status Read(void* data, size_t* length, off_t offset) final;
  tftp_status Write(const void* data, size_t* length, off_t offset) final;
  void Close() final;
  void Abort() final;

  const char* filename() final { return filename_; }

  bool is_write() final { return is_write_; }

 private:
  // Identifies what the file being streamed over TFTP should be
  // used for.
  enum class NetfileType {
    kUnknown,    // No reads/writes currently in progress.
    kNetCopy,    // A file in /data
    kNetboot,    // A bootfs file
    kPaver,      // A disk image which should be paved to disk
    kBoardInfo,  // A file containing the board name.
                 // Expected to return error if it doesn't match the current board name.
  };

  bool is_zedboot_;

  bool is_write_ = false;
  char filename_[PATH_MAX + 1] = {};
  NetfileType type_ = NetfileType::kUnknown;

  // Use when type_ == NetfileType::kBoardName.
  zx::channel sysinfo_;

  // Used when type_ == NetfileType::kNetCopy.
  std::unique_ptr<NetCopyInterface> netcp_;

  // Only valid when type_ == NetfileType::kNetboot.
  nbfile* netboot_file_ = nullptr;

  // Used when type_ == NetfileType::kPaver.
  PaverInterface* paver_;
};

}  // namespace netsvc

#endif  // SRC_BRINGUP_BIN_NETSVC_FILE_API_H_