// 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.

#include "src/bringup/bin/netsvc/file-api.h"

#include <errno.h>
#include <fcntl.h>
#include <lib/component/incoming/cpp/protocol.h>
#include <lib/netboot/netboot.h>
#include <stdio.h>
#include <string.h>

#include "board-info.h"
#include "netboot.h"

namespace netsvc {
namespace {

size_t NETBOOT_IMAGE_PREFIX_LEN() { return strlen(NETBOOT_IMAGE_PREFIX); }
size_t NETBOOT_FILENAME_PREFIX_LEN() { return strlen(NETBOOT_FILENAME_PREFIX); }

}  // namespace

FileApi::FileApi(bool is_zedboot, std::unique_ptr<NetCopyInterface> netcp,
                 fidl::ClientEnd<fuchsia_sysinfo::SysInfo> sysinfo, PaverInterface& paver)
    : is_zedboot_(is_zedboot),
      sysinfo_(std::move(sysinfo)),
      netcp_(std::move(netcp)),
      paver_(paver) {
  if (!sysinfo_) {
    zx::result client_end = component::Connect<fuchsia_sysinfo::SysInfo>();
    if (client_end.is_ok()) {
      sysinfo_ = std::move(client_end.value());
    }
  }
}

ssize_t FileApi::OpenRead(const char* filename, zx::duration) {
  // Make sure all in-progress paving operations have completed
  std::shared_future fut = paver_.exit_code();
  if (fut.wait_for(std::chrono::nanoseconds::zero()) != std::future_status::ready) {
    return TFTP_ERR_SHOULD_WAIT;
  }
  zx_status_t exit_code = fut.get();
  if (exit_code != ZX_OK) {
    fprintf(stderr, "paver exited with error: %s\n", zx_status_get_string(exit_code));
    return TFTP_ERR_IO;
  }

  is_write_ = false;
  strlcpy(filename_, filename, sizeof(filename_));
  netboot_file_ = nullptr;
  size_t file_size;

  if (is_zedboot_ && !strcmp(filename_, NETBOOT_BOARD_INFO_FILENAME)) {
    type_ = NetfileType::kBoardInfo;
    return BoardInfoSize();
  }
  type_ = NetfileType::kNetCopy;
  if (netcp_->Open(filename, O_RDONLY, &file_size) == 0) {
    return static_cast<ssize_t>(file_size);
  }

  return TFTP_ERR_NOT_FOUND;
}

tftp_status FileApi::OpenWrite(const char* filename, size_t size, zx::duration timeout) {
  // Make sure all in-progress paving operations have completed
  std::shared_future fut = paver_.exit_code();
  if (fut.wait_for(std::chrono::nanoseconds::zero()) != std::future_status::ready) {
    return TFTP_ERR_SHOULD_WAIT;
  }
  zx_status_t exit_code = fut.get();
  if (exit_code != ZX_OK) {
    fprintf(stderr, "paver exited with error: %s\n", zx_status_get_string(exit_code));
    return TFTP_ERR_IO;
  }

  is_write_ = true;
  strlcpy(filename_, filename, sizeof(filename_));

  if (is_zedboot_ && !strncmp(filename_, NETBOOT_FILENAME_PREFIX, NETBOOT_FILENAME_PREFIX_LEN())) {
    type_ = NetfileType::kNetboot;
    netboot_file_ = netboot_get_buffer(filename_, size);
    if (netboot_file_ != nullptr) {
      return TFTP_NO_ERROR;
    }
  } else if (is_zedboot_ && !strcmp(filename_, NETBOOT_BOARD_NAME_FILENAME)) {
    printf("netsvc: Running board name validation\n");
    type_ = NetfileType::kBoardInfo;
    return TFTP_NO_ERROR;
  } else if (is_zedboot_ && !strncmp(filename_, NETBOOT_IMAGE_PREFIX, NETBOOT_IMAGE_PREFIX_LEN())) {
    type_ = NetfileType::kPaver;
    tftp_status status = paver_.OpenWrite(filename_, size, timeout);
    if (status != TFTP_NO_ERROR) {
      filename_[0] = '\0';
    }
    return status;
  } else {
    type_ = NetfileType::kNetCopy;
    if (netcp_->Open(filename_, O_WRONLY, nullptr) == 0) {
      return TFTP_NO_ERROR;
    }
  }
  return TFTP_ERR_INVALID_ARGS;
}

tftp_status FileApi::Read(void* data, size_t* length, off_t offset) {
  if (length == nullptr) {
    return TFTP_ERR_INVALID_ARGS;
  }

  switch (type_) {
    case NetfileType::kBoardInfo: {
      zx::result<> status = ReadBoardInfo(sysinfo_, data, offset, length);
      if (status.is_error()) {
        printf("netsvc: Failed to read board information: %s\n", status.status_string());
        return TFTP_ERR_BAD_STATE;
      }
      return TFTP_NO_ERROR;
    }
    case NetfileType::kNetCopy: {
      ssize_t read_len = netcp_->Read(data, offset, *length);
      if (read_len < 0) {
        return TFTP_ERR_IO;
      }
      *length = static_cast<size_t>(read_len);
      return TFTP_NO_ERROR;
    }
    default:
      return ZX_ERR_BAD_STATE;
  }
  return TFTP_ERR_BAD_STATE;
}

tftp_status FileApi::Write(const void* data, size_t* length, off_t offset) {
  if (length == nullptr) {
    return TFTP_ERR_INVALID_ARGS;
  }
  switch (type_) {
    case NetfileType::kNetboot: {
      nbfile_t* nb_file = netboot_file_;
      if ((static_cast<size_t>(offset) > nb_file->size) || (offset + *length) > nb_file->size) {
        return TFTP_ERR_INVALID_ARGS;
      }
      memcpy(nb_file->data + offset, data, *length);
      nb_file->offset = offset + *length;
      return TFTP_NO_ERROR;
    }
    case NetfileType::kPaver:
      return paver_.Write(data, length, offset);

    case NetfileType::kBoardInfo: {
      zx::result status = CheckBoardName(sysinfo_, reinterpret_cast<const char*>(data), *length);
      if (status.is_error()) {
        printf("netsvc: Failed to check board name: %s\n", status.status_string());
        return TFTP_ERR_BAD_STATE;
      }
      if (!status.value()) {
        printf("netsvc: Board name validation failed\n");
        return TFTP_ERR_BAD_STATE;
      }
      printf("netsvc: Board name validation succeeded\n");
      return TFTP_NO_ERROR;
    }
    case NetfileType::kNetCopy: {
      ssize_t write_result = netcp_->Write(reinterpret_cast<const char*>(data), offset, *length);
      if (static_cast<size_t>(write_result) == *length) {
        return TFTP_NO_ERROR;
      }
      if (write_result == -EBADF) {
        return TFTP_ERR_BAD_STATE;
      }
      return TFTP_ERR_IO;
    }
    default:
      return ZX_ERR_BAD_STATE;
  }

  return TFTP_ERR_BAD_STATE;
}

void FileApi::Close() {
  if (type_ == NetfileType::kNetCopy) {
    netcp_->Close();
  } else if (type_ == NetfileType::kPaver) {
    paver_.Close();
  }
  type_ = NetfileType::kUnknown;
}

void FileApi::Abort() {
  if (is_write_) {
    switch (type_) {
      case NetfileType::kNetCopy:
        netcp_->AbortWrite();
        break;
      case NetfileType::kPaver:
        paver_.Abort();
        break;
      default:
        break;
    }
  }
  Close();
}

}  // namespace netsvc