// { dg-do run { target c++23 } }
// { dg-options "-fexec-charset=UTF-8" }
// { dg-timeout-factor 2 }

#include <array>
#include <format>
#include <list>
#include <ranges>
#include <span>
#include <string>
#include <testsuite_hooks.h>
#include <testsuite_iterators.h>
#include <vector>

struct NotFormattable
{};

static_assert(!std::formattable<std::vector<NotFormattable>, char>);
static_assert(!std::formattable<std::span<NotFormattable>, wchar_t>);

template<typename... Args>
bool
is_format_string_for(const char* str, Args&&... args)
{
  try {
    (void) std::vformat(str, std::make_format_args(args...));
    return true;
  } catch (const std::format_error&) {
    return false;
  }
}

template<typename... Args>
bool
is_format_string_for(const wchar_t* str, Args&&... args)
{
  try {
    (void) std::vformat(str, std::make_wformat_args(args...));
    return true;
  } catch (const std::format_error&) {
    return false;
  }
}

template<typename Rg, typename CharT>
bool is_range_formatter_spec_for(CharT const* spec, Rg&& rg)
{
  using V = std::remove_cvref_t<std::ranges::range_reference_t<Rg>>;
  std::range_formatter<V, CharT> fmt;
  std::basic_format_parse_context<CharT> pc(spec);
  try {
    (void)fmt.parse(pc);
    return true;
  } catch (const std::format_error&) {
    return false;
  }
}

void
test_format_string()
{
  // invalid format spec 'p'
  VERIFY( !is_range_formatter_spec_for("p", std::vector<int>()) );
  VERIFY( !is_format_string_for("{:p}", std::vector<int>()) );
  VERIFY( !is_range_formatter_spec_for("np", std::vector<int>()) );
  VERIFY( !is_format_string_for("{:np}", std::vector<int>()) );

  // width needs to be integer type
  VERIFY( !is_format_string_for("{:{}}", std::vector<int>(), 1.0f) );

  // element format needs to be valid
  VERIFY( !is_range_formatter_spec_for(":p", std::vector<int>()) );
  VERIFY( !is_format_string_for("{::p}", std::vector<int>()) );
  VERIFY( !is_range_formatter_spec_for("n:p", std::vector<int>()) );
  VERIFY( !is_format_string_for("{:n:p}", std::vector<int>()) );
}

#define WIDEN_(C, S) ::std::__format::_Widen<C>(S, L##S)
#define WIDEN(S) WIDEN_(CharT, S)

template<typename CharT, typename Range, typename Storage>
void test_output()
{
  using Sv = std::basic_string_view<CharT>;
  using T = std::ranges::range_value_t<Range>;
  auto makeRange = [](Storage& s) -> Range {
    if constexpr (std::is_same_v<std::remove_cvref_t<Range>, Storage>)
      return s;
    else
      return Range(std::ranges::data(s),
		   std::ranges::data(s) + std::ranges::size(s));
  };

  std::basic_string<CharT> res;
  size_t size = 0;

  Storage v1{1, 2, 3};
  res = std::format(WIDEN("{}"), makeRange(v1));
  VERIFY( res == WIDEN("[1, 2, 3]") );
  res = std::format(WIDEN("{:}"), makeRange(v1));
  VERIFY( res == WIDEN("[1, 2, 3]") );
  res = std::format(WIDEN("{:n}"), makeRange(v1));
  VERIFY( res == WIDEN("1, 2, 3") );

  res = std::format(WIDEN("{:3}"), makeRange(v1));
  VERIFY( res == WIDEN("[1, 2, 3]") );

  res = std::format(WIDEN("{:10}"), makeRange(v1));
  VERIFY( res == WIDEN("[1, 2, 3] ") );

  res = std::format(WIDEN("{:{}}"), makeRange(v1), 10);
  VERIFY( res == WIDEN("[1, 2, 3] ") );

  res = std::format(WIDEN("{1:{0}}"), 10, makeRange(v1));
  VERIFY( res == WIDEN("[1, 2, 3] ") );

  res = std::format(WIDEN("{:10n}"), makeRange(v1));
  VERIFY( res == WIDEN("1, 2, 3   ") );

  res = std::format(WIDEN("{:*<11}"), makeRange(v1));
  VERIFY( res == WIDEN("[1, 2, 3]**") );

  res = std::format(WIDEN("{:->12}"), makeRange(v1));
  VERIFY( res == WIDEN("---[1, 2, 3]") );

  res = std::format(WIDEN("{:=^13}"), makeRange(v1));
  VERIFY( res == WIDEN("==[1, 2, 3]==") );

  res = std::format(WIDEN("{:=^13n}"), makeRange(v1));
  VERIFY( res == WIDEN("===1, 2, 3===") );

  res = std::format(WIDEN("{::#x}"), makeRange(v1));
  VERIFY( res == WIDEN("[0x1, 0x2, 0x3]") );

  res = std::format(WIDEN("{:|^25n:#05x}"), makeRange(v1));
  VERIFY( res == WIDEN("|||0x001, 0x002, 0x003|||") );

  // ':' is start of the format string for element
  res = std::format(WIDEN("{::^+04}"), makeRange(v1));
  VERIFY( res == WIDEN("[ +1 ,  +2 ,  +3 ]") );

  size = std::formatted_size(WIDEN("{:}"), makeRange(v1));
  VERIFY( size == Sv(WIDEN("[1, 2, 3]")).size() );

  size = std::formatted_size(WIDEN("{:3}"), makeRange(v1));
  VERIFY( size == Sv(WIDEN("[1, 2, 3]")).size() );

  size = std::formatted_size(WIDEN("{:10}"), makeRange(v1));
  VERIFY( size == 10 );

  size = std::formatted_size(WIDEN("{:|^25n:#05x}"), makeRange(v1));
  VERIFY( size == 25 );
}

template<typename Cont>
void test_output_cont()
{
  test_output<char, Cont&, Cont>();
  test_output<wchar_t, Cont const&, Cont>();
}

template<typename View>
void test_output_view()
{
  test_output<char, View, int[3]>();
  test_output<wchar_t, View, int[3]>();
}

void
test_outputs()
{
  using namespace __gnu_test;
  test_output_cont<std::vector<int>>();
  test_output_cont<std::list<int>>();
  test_output_cont<std::array<int, 3>>();

  test_output_view<std::span<int>>();
  test_output_view<std::ranges::subrange<int*>>();
  test_output_view<test_forward_range<int>>();
  test_output_view<test_input_range<int>>();
  test_output_view<test_input_range_nocopy<int>>();

  test_output_view<std::span<const int>>();
  test_output_view<std::ranges::subrange<const int*>>();
  test_output_view<test_forward_range<const int>>();
}

void
test_nested()
{
  std::vector<std::vector<int>> v
  {
    {1, 2},
    {11, 12}
  };

  std::string res = std::format("{}", v);
  VERIFY( res == "[[1, 2], [11, 12]]" );

  res = std::format("{:+^18:n:02}", v);
  VERIFY( res == "+[01, 02, 11, 12]+" );
}

bool strip_quote(std::string_view& v)
{
  if (!v.starts_with('"'))
    return false;
  v.remove_prefix(1);
  return true;
}

bool strip_prefix(std::string_view& v, std::string_view expected, bool quoted = false)
{
  if (quoted && !strip_quote(v))
    return false;
  if (!v.starts_with(expected))
    return false;
  v.remove_prefix(expected.size());
  if (quoted && !strip_quote(v))
    return false;
  return true;
}

bool strip_squares(std::string_view& v)
{
  if (!v.starts_with('[') || !v.ends_with(']'))
    return false;
  v.remove_prefix(1);
  v.remove_suffix(1);
  return true;
}

bool strip_prefix(std::string_view& v, size_t n, char c)
{
  size_t pos = v.find_first_not_of(c);
  if (pos == std::string_view::npos)
    pos = v.size();
  if (pos != n)
    return false;
  v.remove_prefix(n);
  return true;
}

void test_padding()
{
  std::string res;
  std::string_view resv;

  // width is 3, size is 15
  std::string in = "o\u0302\u0323i\u0302\u0323u\u0302\u0323";
  in += in; // width is 6, size is 30
  in += in; // width is 12, size is 60
  in += in; // width is 24, size is 120
  in += in; // width is 48, size is 240
  // width is 192, size is 960
  std::vector<std::string> const vs{in, in, in, in};

  auto const check_elems = [=](std::string_view& v, bool quoted)
  {
    VERIFY( strip_prefix(v, in, quoted) );
    VERIFY( strip_prefix(v, ", ", false) );
    VERIFY( strip_prefix(v, in, quoted) );
    VERIFY( strip_prefix(v, ", ", false) );
    VERIFY( strip_prefix(v, in, quoted) );
    VERIFY( strip_prefix(v, ", ", false) );
    VERIFY( strip_prefix(v, in, quoted) );
    return v.empty();
  };

  resv = res = std::format("{}", vs);
  VERIFY( strip_squares(resv) );
  VERIFY( check_elems(resv, true) );

  resv = res = std::format("{:n}", vs);
  VERIFY( check_elems(resv, true) );

  resv = res = std::format("{::}", vs);
  VERIFY( strip_squares(resv) );
  VERIFY( check_elems(resv, false) );

  resv = res = std::format("{:n:}", vs);
  VERIFY( check_elems(resv, false) );

  resv = res = std::format("{:*>10}", vs);
  VERIFY( strip_squares(resv) );
  VERIFY( check_elems(resv, true) );

  resv = res = std::format("{:*>10n}", vs);
  VERIFY( check_elems(resv, true) );

  resv = res = std::format("{:*>10:}", vs);
  VERIFY( strip_squares(resv) );
  VERIFY( check_elems(resv, false) );

  resv = res = std::format("{:*>10n:}", vs);
  VERIFY( check_elems(resv, false) );

  resv = res = std::format("{:*>256}", vs);
  VERIFY( strip_prefix(resv, 48, '*') );
  VERIFY( strip_squares(resv) );
  VERIFY( check_elems(resv, true) );

  resv = res = std::format("{:*>256n}", vs);
  VERIFY( strip_prefix(resv, 50, '*') );
  VERIFY( check_elems(resv, true) );

  resv = res = std::format("{:*>240}", vs);
  VERIFY( strip_prefix(resv, 32, '*') );
  VERIFY( strip_squares(resv) );
  VERIFY( check_elems(resv, true) );

  resv = res = std::format("{:*>240n}", vs);
  VERIFY( strip_prefix(resv, 34, '*') );
  VERIFY( check_elems(resv, true) );

  resv = res = std::format("{:*>240:}", vs);
  VERIFY( strip_prefix(resv, 40, '*') );
  VERIFY( strip_squares(resv) );
  VERIFY( check_elems(resv, false) );

  resv = res = std::format("{:*>240n:}", vs);
  VERIFY( strip_prefix(resv, 42, '*') );
  VERIFY( check_elems(resv, false) );
}

int main()
{
  test_format_string();
  test_outputs();
  test_nested();
  test_padding();
}