#pragma once

#include <array>
#include <vector>
#include <type_traits>

#include "RetroTypes.hpp"

namespace aurora {
template <typename T>
class ArrayRef {
public:
  using value_type = std::remove_cvref_t<T>;
  using pointer = value_type*;
  using const_pointer = const value_type*;
  using reference = value_type&;
  using const_reference = const value_type&;
  using iterator = const_pointer;
  using const_iterator = const_pointer;
  using reverse_iterator = std::reverse_iterator<iterator>;
  using const_reverse_iterator = std::reverse_iterator<const_iterator>;
  using size_type = std::size_t;
  using difference_type = std::ptrdiff_t;

  ArrayRef() = default;
  explicit ArrayRef(const T& one) : ptr(&one), length(1) {}
  ArrayRef(const T* data, size_t length) : ptr(data), length(length) {}
  ArrayRef(const T* begin, const T* end) : ptr(begin), length(end - begin) {}
  template <size_t N>
  constexpr ArrayRef(const T (&arr)[N]) : ptr(arr), length(N) {}
  template <size_t N>
  constexpr ArrayRef(const std::array<T, N>& arr) : ptr(arr.data()), length(arr.size()) {}
  ArrayRef(const std::vector<T>& vec) : ptr(vec.data()), length(vec.size()) {}
  template <size_t N>
  ArrayRef(const rstl::reserved_vector<T, N>& vec) : ptr(vec.data()), length(vec.size()) {}

  const T* data() const { return ptr; }
  size_t size() const { return length; }
  bool empty() const { return length == 0; }

  const T& front() const {
    assert(!empty());
    return ptr[0];
  }
  const T& back() const {
    assert(!empty());
    return ptr[length - 1];
  }
  const T& operator[](size_t i) const {
    assert(i < length && "Invalid index!");
    return ptr[i];
  }

  iterator begin() const { return ptr; }
  iterator end() const { return ptr + length; }

  reverse_iterator rbegin() const { return reverse_iterator(end()); }
  reverse_iterator rend() const { return reverse_iterator(begin()); }

  /// Disallow accidental assignment from a temporary.
  template <typename U>
  std::enable_if_t<std::is_same<U, T>::value, ArrayRef<T>>& operator=(U&& Temporary) = delete;

  /// Disallow accidental assignment from a temporary.
  template <typename U>
  std::enable_if_t<std::is_same<U, T>::value, ArrayRef<T>>& operator=(std::initializer_list<U>) = delete;

private:
  const T* ptr = nullptr;
  size_t length = 0;
};
} // namespace aurora