// Copyright 2023 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine License
// Agreement.
//
//  Reference implementation utilities of OEMCrypto APIs
//
#ifndef WVOEC_UTIL_CBOR_VALIDATOR_H_
#define WVOEC_UTIL_CBOR_VALIDATOR_H_

#include <inttypes.h>

#include <string>
#include <utility>
#include <vector>

#include "cppbor.h"
#include "cppbor_parse.h"
#include "wv_class_utils.h"

namespace wvoec {
namespace util {
// CborMessageStatus values are ranked in level of severity.
// kCborUninitialized being the lowest severity, and
// kCborValidateFatal being the highest.
enum CborMessageStatus {
  kCborUninitialized = 0,
  kCborParseOk = 1,
  kCborParseError = 2,
  kCborValidateOk = 3,
  kCborValidateWarning = 4,
  kCborValidateError = 5,
  kCborValidateFatal = 6
};

std::string CppborMajorTypeToString(cppbor::MajorType type);
std::string CborMessageStatusToString(CborMessageStatus status);

class CborValidator {
 public:
  CborValidator() = default;
  WVCDM_DISALLOW_COPY_AND_MOVE(CborValidator);
  virtual ~CborValidator() = default;

  // Decodes |cbor| and sets |message_status_|.
  virtual CborMessageStatus Parse(const std::vector<uint8_t>& cbor);
  const cppbor::ParseResult* GetParseResult() const;
  // Returns pretty-printed CBOR for |parse_result_|. Returns empty string if
  // |parse_result_| is not valid.
  std::string GetRawMessage() const;

  // Verifies the fields in |parse_result_| to have expected types and values.
  // Requires that Parse() is called first and |parse_result_| contains a valid
  // CBOR message.
  virtual CborMessageStatus Validate();
  // Returns all validation messages from Validate().
  const std::vector<std::pair<CborMessageStatus, std::string>>&
  GetValidateMessages() const {
    return validate_messages_;
  }
  // Prints |parse_result_| in readable format. Requires that Parse() is called
  // first and |parse_result_| contains a valid CBOR message.
  virtual std::string GetFormattedMessage() const;
  const cppbor::ParseResult& parse_result() const { return parse_result_; }
  const std::vector<std::pair<CborMessageStatus, std::string>>&
  validate_messages() {
    return validate_messages_;
  }

 protected:
  void Reset();
  // Writes validation output |msg| to |validate_messages_|, and updates
  // |message_status_| if the |status| is more severe than the current value.
  void AddValidationMessage(CborMessageStatus status, const std::string& msg);
  static const cppbor::Item* GetMapEntry(const cppbor::Map& map,
                                         const std::string& entry_name);
  // Checks whether an entry with |entry_name| and |major_type| exists in |map|.
  static std::string CheckMapEntry(const cppbor::Map& map,
                                   cppbor::MajorType major_type,
                                   const std::string& entry_name);
  CborMessageStatus message_status_ = kCborUninitialized;

 private:
  // Internal status of parsing and validating.
  cppbor::ParseResult parse_result_ = {};
  std::vector<std::pair<CborMessageStatus, std::string>> validate_messages_;
};  // class CborValidator
}  // namespace util
}  // namespace wvoec
#endif  // WVOEC_UTIL_CBOR_VALIDATOR_H_