formats/bmff/xpath.h

// Copyright 2026 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
//
//    https://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.
//

#ifndef THIRD_PARTY_CREDENTIO_FORMATS_BMFF_XPATH_H_
#define THIRD_PARTY_CREDENTIO_FORMATS_BMFF_XPATH_H_

#include <optional>
#include <string>

#include "absl/strings/string_view.h"

namespace credentio {

// An XPath represents a path from the root to a BMFF box, with the formatted
// string according to https://www.w3.org/TR/xpath-10/.
class XPath {
 public:
  // Constructs an XPath with a parent and a name.
  XPath(const XPath* parent, std::string name) : parent_(parent), name_(name) {}

  // Constructs an XPath with a parent, a name, and a position.
  XPath(const XPath* parent, std::string name, int position)
      : parent_(parent), name_(name), position_(position) {}

  // Sets the position of the element for this path.
  void SetPosition(int position) { position_ = position; }
  // Returns the string representation of this full path.
  std::string ToString() const;

 private:
  // The parent of this path.
  const XPath* parent_;
  // The name of the element pointed by this path.
  std::string name_;
  // The position of the element for this path. The position represents that
  // this path is the Nth child with tag name in its parent.
  std::optional<int> position_ = std::nullopt;
};

// A util class to match a XPath.
class XPathMatcher {
 public:
  explicit XPathMatcher(absl::string_view pattern) : pattern_(pattern) {}
  bool Matches(absl::string_view path) const;

 private:
  std::string pattern_;
};

}  // namespace credentio

#endif  // THIRD_PARTY_CREDENTIO_FORMATS_BMFF_XPATH_H_