//  Copyright 2021 Herald Project Contributors

//  SPDX-License-Identifier: Apache-2.0

//

#include "herald/payload/simple/f.h"

#include "herald/datatype/data.h"

#include "herald/datatype/sha256.h"

namespace herald {

namespace payload {

namespace simple {

using namespace herald::datatype;

namespace F {

[[maybe_unused]]

Data h(const Data& data) noexcept {

  SHA256 sha;

  return sha.digest(data);

}

[[maybe_unused]]

Data t(const Data& data) noexcept {

  return t(data,data.size() / 2);

}

[[maybe_unused]]

Data t(const Data& data, int n) noexcept {

  return data.subdata(0,n);

}

[[maybe_unused]]

Data xorData(const Data& left, const Data& right) noexcept {

  Data result;

  // note: we're ensuring we don't have an out of bound index (has effect of XOR with 0 as we set value above)

  for (std::size_t i = 0;i < right.size() && i < left.size();i++) {

    result.append(std::byte(((int)left.at(i)) ^ ((int)right.at(i))));

  }

  if (right.size() < left.size()) {

    for (std::size_t i = left.size();i < left.size();i++) {

      result.append(left.at(i));

    }

  }

  return result;

}

} // end namespace f

}

}

}