// Copyright 2024 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine License
// Agreement.
//
#ifndef WVOEC_UTIL_PROV4_VALIDATION_HELPER_H_
#define WVOEC_UTIL_PROV4_VALIDATION_HELPER_H_

#include <sstream>

#include "cbor_validator.h"
#include "string_conversions.h"

namespace wvoec {
namespace util {

enum FieldStatus {
  kAbsent = 0,  // field key doesn't exist
  kEmpty = 1,   // field value is empty, e.g. empty string, map, array, etc.
  kPresent = 2  // present and non-empty
};

std::string StatusToString(FieldStatus status);
// Apply a new status to current status if it is more severe.
void ApplyStatus(CborMessageStatus& status, CborMessageStatus new_status);

// Validates that the given field name is present, and prints error messages
// if not. It is acceptable that some field, although specified as required by
// DICE specification, is not present in practice. This function will return
// kCborValidateWarning instead of the default kCborValidateError in those
// cases.
template <typename T>
CborMessageStatus ValidateRequiredField(
    const std::string& name, const std::string& component,
    const std::pair<FieldStatus, T>& p,
    std::vector<std::pair<CborMessageStatus, std::string>>& msgs,
    CborMessageStatus error = kCborValidateError) {
  if (p.first != kPresent) {
    msgs.push_back(
        std::make_pair(error, component + ": missing required field " + name));
    return error;
  }
  return kCborValidateOk;
}

// Validates that the given field name is present, and prints warning messages
// if not.
template <typename T>
CborMessageStatus ValidateImportantField(
    const std::string& name, const std::string& component,
    const std::pair<FieldStatus, T>& p,
    std::vector<std::pair<CborMessageStatus, std::string>>& msgs) {
  if (p.first != kPresent) {
    msgs.push_back(std::make_pair(
        kCborValidateWarning, component + ": missing important field " + name));
    return kCborValidateWarning;
  }
  return kCborValidateOk;
}

// Print a field value with a built-in type in component with |name| to
// stringstream.
template <typename T>
void PrintField(std::stringstream& ss, const std::string& name,
                const std::pair<FieldStatus, T>& p) {
  ss << " " << name << ":";
  if (p.first != kPresent) {
    ss << StatusToString(p.first) << ",";
  } else {
    ss << p.second << ",";
  }
}

// Print a field encoded as a CBOR bstr in component with |name| to
// stringstream.
template <typename T>
void PrintBstrField(std::stringstream& ss, const std::string& name,
                    const std::pair<FieldStatus, T>& p) {
  ss << " " << name << ":";
  if (p.first != kPresent) {
    ss << StatusToString(p.first) << ",";
  } else {
    ss << wvutil::b2a_hex(p.second) << ",";
  }
}

// Print a field encoded as CBOR structure in component with |name| to
// stringstream.
template <typename T>
void PrintCborField(std::stringstream& ss, const std::string& name,
                    const std::pair<FieldStatus, T>& p) {
  ss << " " << name << ":";
  if (p.first != kPresent) {
    ss << StatusToString(p.first) << ",";
  } else {
    ss << p.second.ToString() << ",";
  }
}
}  // namespace util
}  // namespace wvoec
#endif  // WVOEC_UTIL_PROV4_VALIDATION_HELPER_H_