#include <kstd/flat_map>
#include <kstd/format>
#include <kstd/tests/os_panic.hpp>

#include <catch2/catch_test_macros.hpp>

#include <iterator>
#include <sstream>

SCENARIO("Formatting to a new string", "[format]")
{
  GIVEN("a format string without any placeholders")
  {
    auto const & fmt = "This is a test";

    WHEN("calling format with without any arguments.")
    {
      auto result = kstd::format(fmt);

      THEN("the result is the unmodified string")
      {
        REQUIRE(result == "This is a test");
      }
    }

    WHEN("calling format with additional arguments")
    {
      auto result = kstd::format(fmt, 1, 2, 3);

      THEN("the result is the unmodified string")
      {
        REQUIRE(result == "This is a test");
      }
    }
  }

  GIVEN("a format string with placeholders")
  {
    auto const & fmt = "Here are some placeholders: {} {} {}";

    WHEN("calling format with the same number of arguments as there are placeholders")
    {
      auto result = kstd::format(fmt, 1, true, 'a');

      THEN("the result is the formatted string")
      {
        REQUIRE(result == "Here are some placeholders: 1 true a");
      }
    }

    WHEN("calling format with too many arguments")
    {
      auto result = kstd::format(fmt, 2, false, 'b', 4, 5, 6);

      THEN("the result is the formatted string")
      {
        REQUIRE(result == "Here are some placeholders: 2 false b");
      }
    }
  }
}

SCENARIO("Formatting to an output iterator", "[format]")
{
  auto buffer = std::ostringstream{};

  GIVEN("a format string without any placeholders")
  {
    auto const & fmt = "This is a test";

    WHEN("calling format with without any arguments.")
    {
      kstd::format_to(std::ostream_iterator<char>{buffer}, fmt);

      THEN("the unmodified string is written to the iterator")
      {
        REQUIRE(buffer.str() == "This is a test");
      }
    }

    WHEN("calling format with additional arguments")
    {
      kstd::format_to(std::ostream_iterator<char>{buffer}, fmt, 1, 2, 3);

      THEN("the unmodified string is written to the iterator")
      {
        REQUIRE(buffer.str() == "This is a test");
      }
    }
  }

  GIVEN("a format string with placeholders")
  {
    auto const & fmt = "Here are some placeholders: {} {} {}";

    WHEN("calling format with the same number of arguments as there are placeholders")
    {
      kstd::format_to(std::ostream_iterator<char>{buffer}, fmt, 1, true, -100);

      THEN("the formatted string is written to the iterator")
      {
        REQUIRE(buffer.str() == "Here are some placeholders: 1 true -100");
      }
    }

    WHEN("calling format with too many arguments")
    {
      kstd::format_to(std::ostream_iterator<char>{buffer}, fmt, 2, false, -200, 4, 5, 6);

      THEN("the formatted string is written to the iterator")
      {
        REQUIRE(buffer.str() == "Here are some placeholders: 2 false -200");
      }
    }
  }
}