// Formatting library for C++ - the core API
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
//
// Copyright (c) 2018 - present, Remotion (Igor Schulz)
// All Rights Reserved
// {fmt} support for ranges, containers and types tuple interface.

#ifndef FMT_RANGES_H_
#define FMT_RANGES_H_

#include "format.h"
#include <type_traits>

// output only up to N items from the range.
#ifndef FMT_RANGE_OUTPUT_LENGTH_LIMIT
# define FMT_RANGE_OUTPUT_LENGTH_LIMIT 256
#endif

FMT_BEGIN_NAMESPACE

template <typename Char>
struct formatting_base {
  template <typename ParseContext>
  FMT_CONSTEXPR auto parse(ParseContext &ctx) -> decltype(ctx.begin()) {
    return ctx.begin();
  }
};

template <typename Char, typename Enable = void>
struct formatting_range : formatting_base<Char> {
  static FMT_CONSTEXPR_DECL const std::size_t range_length_limit =
      FMT_RANGE_OUTPUT_LENGTH_LIMIT; // output only up to N items from the range.
  Char prefix = '{';
  Char delimiter = ',';
  Char postfix = '}';
  static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
  static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
};

template <typename Char, typename Enable = void>
struct formatting_tuple : formatting_base<Char> {
  Char prefix = '(';
  Char delimiter = ',';
  Char postfix = ')';
  static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
  static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
};

namespace internal {

template <typename RangeT, typename OutputIterator>
void copy(const RangeT &range, OutputIterator out) {
  for (const auto &it : range) {
    *out++ = it;
  }
}

template <typename OutputIterator>
void copy(const char *str, OutputIterator out) {
  const char *p_curr = str;
  while (*p_curr) {
    *out++ = *p_curr++;
  }
}

template <typename OutputIterator>
void copy(char ch, OutputIterator out) {
  *out++ = ch;
}

/// Return true value if T has std::string interface, like std::string_view.
template <typename T>
class is_like_std_string {
  template <typename U>
  static auto check(U *p) ->
    decltype(p->find('a'), p->length(), p->data(), int());
  template <typename>
  static void check(...);

 public:
  static FMT_CONSTEXPR_DECL const bool value =
    !std::is_void<decltype(check<T>(nullptr))>::value;
};

template <typename... Ts>
struct conditional_helper {};

template <typename T, typename _ = void>
struct is_range_ : std::false_type {};

template <typename T>
struct is_range_<T,typename std::conditional<
                   false,
                   conditional_helper<decltype(std::declval<T>().begin()),
                                      decltype(std::declval<T>().end())>,
                   void>::type> : std::true_type {};

template <typename T>
struct is_range {
  static FMT_CONSTEXPR_DECL const bool value =
    is_range_<T>::value && !is_like_std_string<T>::value;
};

/// tuple_size and tuple_element check.
template <typename T>
class is_tuple_like_ {
  template <typename U>
  static auto check(U *p) ->
    decltype(std::tuple_size<U>::value,
             std::declval<typename std::tuple_element<0, U>::type>(), int());
  template <typename>
  static void check(...);

 public:
  static FMT_CONSTEXPR_DECL const bool value =
    !std::is_void<decltype(check<T>(nullptr))>::value;
};

template <typename T>
struct is_tuple_like {
  static FMT_CONSTEXPR_DECL const bool value =
    is_tuple_like_<T>::value && !is_range_<T>::value;
};

template <size_t... Is, class Tuple, class F>
void for_each(std::index_sequence<Is...>, Tuple &&tup, F &&f) noexcept {
  using std::get;
  // using free function get<I>(T) now.
  const int _[] = {0, ((void)f(get<Is>(tup)), 0)...};
  (void)_;  // blocks warnings
}

template <class T>
FMT_CONSTEXPR std::make_index_sequence<std::tuple_size<T>::value> 
get_indexes(T const &) { return {}; }

template <class Tuple, class F>
void for_each(Tuple &&tup, F &&f) {
  const auto indexes = get_indexes(tup);
  for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
}
}  // namespace internal

template <typename TupleT, typename Char>
struct formatter<TupleT, Char, 
    typename std::enable_if<fmt::internal::is_tuple_like<TupleT>::value>::type> {

  fmt::formatting_tuple<Char> formatting;

  template <typename ParseContext>
  FMT_CONSTEXPR auto parse(ParseContext &ctx) -> decltype(ctx.begin()) {
    return formatting.parse(ctx);
  }

  template <typename FormatContext = format_context>
  auto format(const TupleT &values, FormatContext &ctx) -> decltype(ctx.out()) {
    auto out = ctx.out();
    std::size_t i = 0;
    internal::copy(formatting.prefix, out);
    internal::for_each(values, [&](const auto &v) {
      if (i > 0) {
        if (formatting.add_prepostfix_space) {
          *out++ = ' ';
        }
        internal::copy(formatting.delimiter, out);
      }
      if (formatting.add_delimiter_spaces && i > 0) {
        format_to(out, " {}", v);
      } else {
        format_to(out, "{}", v);
      }
      ++i;
    });
    if (formatting.add_prepostfix_space) {
      *out++ = ' ';
    }
    internal::copy(formatting.postfix, out);

    return ctx.out();
  }
};

template <typename RangeT, typename Char>
struct formatter< RangeT, Char,
    typename std::enable_if<fmt::internal::is_range<RangeT>::value>::type> {

  fmt::formatting_range<Char> formatting;

  template <typename ParseContext>
  FMT_CONSTEXPR auto parse(ParseContext &ctx) -> decltype(ctx.begin()) {
    return formatting.parse(ctx);
  }

  template <typename FormatContext>
  auto format(const RangeT &values, FormatContext &ctx) -> decltype(ctx.out()) {
    auto out = ctx.out();
    internal::copy(formatting.prefix, out);
    std::size_t i = 0;
    for (const auto &it : values) {
      if (i > 0) {
        if (formatting.add_prepostfix_space) {
          *out++ = ' ';
        }
        internal::copy(formatting.delimiter, out);
      }
      if (formatting.add_delimiter_spaces && i > 0) {
        format_to(out, " {}", it);
      } else {
        format_to(out, "{}", it);
      }
      if (++i > formatting.range_length_limit) {
        format_to(out, " ... <other elements>");
        break;
      }
    }
    if (formatting.add_prepostfix_space) {
      *out++ = ' ';
    }
    internal::copy(formatting.postfix, out);
    return ctx.out();
  }
};

FMT_END_NAMESPACE

#endif // FMT_RANGES_H_