// Copyright 2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#pragma once

#include <cstddef>
#include <cstdint>

#include "ec_util_interface.hpp"
#include "google3/host_commands.h"
#include "host_command.hpp"

namespace google {
namespace hoth {
namespace internal {

class CommandNotSupportedException : public std::exception {
 public:
  explicit CommandNotSupportedException(uint16_t command) : command(command) {
    std::stringstream ss;
    ss << "EC Command 0x" << std::hex << command << " not supported";
    this->message = ss.str();
  }
  const char* what() const noexcept override { return message.c_str(); }

  uint16_t get_command() const { return command; }

 private:
  uint16_t command;
  std::string message;
};

class CommandRunException : public std::exception {
 public:
  explicit CommandRunException(uint16_t command, uint16_t result)
      : command(command), result(result) {
    std::stringstream ss;
    ss << "EC Command 0x" << std::hex << command << " returned error 0x"
       << std::hex << result;
    this->message = ss.str();
  }
  const char* what() const noexcept override { return message.c_str(); }

  uint16_t get_command() const { return command; }
  uint16_t get_result() const { return result; }

 private:
  uint16_t command;
  uint16_t result;
  std::string message;
};

class EcUtilImpl : public EcUtil {
 public:
  explicit EcUtilImpl(HostCommand* hostCmd) : hostCmd(hostCmd) {}

  // Check wether a command is supported and authorized.
  bool isHostCommandSupported(uint16_t cmd) const override;

  // Get the Hoth statistics by issuing an EC_PRV_CMD_HOTH_GET_STATISTICS
  // Command.
  ec_response_statistics getHothStatistics() const override;

  // Get the hardware information from Hoth chip by issuing an
  // EC_PRV_CMD_HOTH_CHIP_INFO command.
  ec_response_chip_info getHothChipInfo() const override;

  // Get the Hoth persistent panic info by issuing a series of
  // EC_PRV_CMD_HOTH_PERSISTENT_PANIC_INFO commands.
  std::optional<ec_response_persistent_panic_info> getHothPersistentPanicInfo()
      const;

  // Check the presence of Hoth peresistent panic info by issuing a single
  // EC_PRV_CMD_HOTH_PERSISTENT_PANIC_INFO command.
  bool checkHothPersistentPanicInfo() const override;

  // Get the Hoth auth record.
  // Only supports record id = 0, which is the only one currently used.
  ec_authz_record_get_response getHothAuthRecord() const override;

  ec_response_key_rotation_status getHothKeyRotationStatus() const override;

 private:
  [[nodiscard]] std::vector<uint8_t> sendCommand(uint16_t command,
                                                 uint8_t* request_ptr,
                                                 size_t request_size) const;

  /** @brief Connection to Hoth for sending and receiving host commands */
  HostCommand* hostCmd;
};

}  // namespace internal

}  // namespace hoth

}  // namespace google