// ArduinoJson - https://arduinojson.org

// Copyright © 2014-2025, Benoit BLANCHON

// MIT License

#pragma once

#include <ArduinoJson/Array/JsonArrayIterator.hpp>

#include <ArduinoJson/Variant/VariantAttorney.hpp>

#include <ArduinoJson/Variant/VariantData.hpp>

ARDUINOJSON_BEGIN_PUBLIC_NAMESPACE

class JsonObject;

// A read-only reference to an array in a JsonDocument

// https://arduinojson.org/v7/api/jsonarrayconst/

class JsonArrayConst : public detail::VariantOperators<JsonArrayConst> {

  friend class JsonArray;

  friend class detail::VariantAttorney;

 public:

  using iterator = JsonArrayConstIterator;

  // Returns an iterator to the first element of the array.

  // https://arduinojson.org/v7/api/jsonarrayconst/begin/

  iterator begin() const {

    return iterator(impl_.createIterator(), impl_.resources());

  }

  // Returns an iterator to the element following the last element of the array.

  // https://arduinojson.org/v7/api/jsonarrayconst/end/

  iterator end() const {

    return iterator();

  }

  // Creates an unbound reference.

  JsonArrayConst() {}

  // INTERNAL USE ONLY

  JsonArrayConst(detail::VariantData* data, detail::ResourceManager* resources)

      : impl_(data, resources) {}

  // INTERNAL USE ONLY

  JsonArrayConst(const detail::VariantImpl& impl) : impl_(impl) {}

  // Returns the element at the specified index.

  // https://arduinojson.org/v7/api/jsonarrayconst/subscript/

  template <typename T,

            detail::enable_if_t<detail::is_integral<T>::value, int> = 0>

  JsonVariantConst operator[](T index) const {

    return JsonVariantConst(impl_.getElement(size_t(index)), impl_.resources());

  }

  // Returns the element at the specified index.

  // https://arduinojson.org/v7/api/jsonarrayconst/subscript/

  template <typename TVariant,

            detail::enable_if_t<detail::IsVariant<TVariant>::value, int> = 0>

  JsonVariantConst operator[](const TVariant& variant) const {

    if (variant.template is<size_t>())

      return operator[](variant.template as<size_t>());

    else

      return JsonVariantConst();

  }

  operator JsonVariantConst() const {

    return JsonVariantConst(impl_.data(), impl_.resources());

  }

  // Returns true if the reference is unbound.

  // https://arduinojson.org/v7/api/jsonarrayconst/isnull/

  bool isNull() const {

    return impl_.isNull();

  }

  // Returns true if the reference is bound.

  // https://arduinojson.org/v7/api/jsonarrayconst/isnull/

  operator bool() const {

    return !isNull();

  }

  // Returns the depth (nesting level) of the array.

  // https://arduinojson.org/v7/api/jsonarrayconst/nesting/

  size_t nesting() const {

    return impl_.nesting();

  }

  // Returns the number of elements in the array.

  // https://arduinojson.org/v7/api/jsonarrayconst/size/

  size_t size() const {

    return impl_.size();

  }

  // DEPRECATED: always returns zero

  ARDUINOJSON_DEPRECATED("always returns zero")

  size_t memoryUsage() const {

    return 0;

  }

 private:

  const detail::VariantData* getData() const {

    return impl_.data();

  }

  detail::VariantImpl impl_;

};

// Compares the content of two arrays.

// Returns true if the two arrays are equal.

inline bool operator==(JsonArrayConst lhs, JsonArrayConst rhs) {

  if (!lhs && !rhs)

    return true;

  if (!lhs || !rhs)

    return false;

  auto a = lhs.begin();

  auto b = rhs.begin();

  for (;;) {

    if (a == b)  // same pointer or both null

      return true;

    if (a == lhs.end() || b == rhs.end())

      return false;

    if (*a != *b)

      return false;

    ++a;

    ++b;

  }

}

ARDUINOJSON_END_PUBLIC_NAMESPACE